Metropolitan estuaries and sea-level rise:
Adaptive environmental planning solutions at the regional scale
By
Pedro Janela Pinto
A dissertation submitted in partial satisfaction of the
requirements for the degree of
Doctor of Philosophy
in
Landscape Architecture and Environmental Planning
in the
Graduate Division
of the
University of California, Berkeley
Committee in charge:
Professor G. Mathias Kondolf, Chair
Professor Louise A. Mozingo
Professor Vincent H. Resh
Summer 2015
Metropolitan estuaries and sea-level rise:
Adaptive environmental planning solutions at the regional scale
Copyright ©2015
Pedro Janela Pinto
Copyright page
ABSTRACT
Metropolitan estuaries and sea-level rise: Adaptive environmental planning solutions
at the regional scale
by
Pedro Janela Pinto
Doctor of Philosophy in Landscape Architecture and Environmental Planning
University of California, Berkeley
Professor G. Mathias Kondolf, Chair
Wide estuaries are natural magnets for urban development. Several of the World’s
major cities developed around estuaries, but at the same time encroached upon some
of the most complex and vital ecosystems. Sea-level rise threatens to submerge both
rare wetland habitat and essential urban areas and infrastructure. This prospect
discloses the urgency of balancing urban development and environmental protection
in Metropolitan Estuaries. The hard task of dealing with this threat may provide the
opportunity to promote an integrated approach to regional planning, where the
necessary adaptation of cities to sea-level rise could equally promote the
preservation, or even the enhancement, of wetland habitat.
The two case study metropolitan estuaries, San Francisco Bay (California, USA) and
the Tagus Estuary (Lisbon, Portugal), share striking similarities in terms of
morphology. They both host large metropolitan areas and important wetland
ecosystems. Nevertheless, a finer analysis of development patterns reveals crucial
differences in the extent of shoreline alteration and types of land use that now
encroach upon natural estuarine habitat. The comparative study of both estuaries
provides mutually beneficial insights on the shortcomings of each system, and helps
identify opportunities to enhance coastal zone management, adaptive governance and
environmental planning efforts.
The evolution of both estuaries throughout the Holocene is reconstructed, with
special emphasis on the process of anthropogenic alteration. While this impact has
been significant and continuous in the Tagus Estuary for over two millennia, large
scale disturbance of the San Francisco Bay was concentrated in the last two centuries.
The legal frameworks that have guided, with varying degrees of effectiveness, the
process of wetland reclamation and landfilling share a common ancestry in the Roman
Law. These have evolved continuously in Lisbon and the State has upheld with
relative success the provision to keep estuarine lowlands in public control, even as
they were steadily transformed to farmland. In San Francisco, a period of deep
1
disturbances over the Sacramento River’s hydrology was coupled with extremely fast
and under regulated development of lowlands. During a short period, the property of
these lands, which would theoretically fall within the Public Trust, was transferred to
local governments and private landowners, which led to their steady transformation
onto salt ponds, industrial zones and even residential neighborhoods. As a
consequence, the Bay Area now has extensive developed areas at very low elevations,
vulnerable to low levels of sea-level rise, and remaining wetlands are now heavily
encroached upon by urban development. Around the Tagus Estuary, while most
original wetlands have long been drained for farmland, the remaining patches are
adjacent to non-urban land uses, which could facilitate future efforts of restoration or
allow wetland migration with rising seas.
A comparative modelling of sea-level rise flooding over existing land uses reveals that,
while around the Tagus Estuary most reclaimed lowlands are reserved for farmland
and urban development over landfill is limited, the extent of developed urban areas at
very low elevations is much greater around the SF Bay, which renders the region more
vulnerable to early stages of SLR. Nonetheless, both cities have begun to incorporate
climate adaptation onto their main environmental planning blueprints, for which they
can be seen as early adopters of local sea-level rise adaptation strategies. Through
interviews with stakeholders and document analysis, the planning and decisionmaking exercises that led to the recent elaboration of the first Tagus Estuary
Management Plan, and the Bay Plan Climate Change Amendment, are analyzed and
discussed.
Lisbon benefits from a very simple, top-down, planning structure, with a handful of
public entities directly communicating and articulating stakes and approaches along
the planning process. A lack of transparency as to some specific interventions and a
still somewhat incipient tradition of public participation have contributed to protract
the Plan’s final approval.
The Bay Area institutional framework is well-used to collaborative planning efforts,
which are usually successful in articulating conflicting interests, but are prone to
limitations derived from narrow, and often difficult to expand, mandates for
environmental planning agencies, within an extremely complex, multi-level,
governance structure involving three levels of government and very active interest
groups.
While broad mitigation/adaptation strategies are decided at the National or State
levels, the actual implementation of SLR adaptation measures often require a great
deal of involvement of local actors. Given that it is at this juncture that adaptation
takes a concrete spatial expression, this is also the moment when land-use conflicts
arise. Local governments are left with much of the burden of mediating competing
interests, between urban development, environmental protection, and other social
demands. In some instances, the prospect of shoreline development may be very
attractive for both property owners/developers and local governments, given the
2
potential land value and economic benefits, but these have to be weighed against the
medium-/long-term costs of defending these assets from rising sea-levels.
In San Francisco Bay, there is an increasing awareness of the challenges posed by SLR,
but the institutional arrangements are complex, and communication between the
different public agencies/departments is not always as streamlined as it could be.
Some agencies and departments need to adapt their procedures in order to remove
institutional barriers to adaptation, but path dependence is an obstacle. The several
projects where different federal and state agencies are partnered with local
governments highlight the benefits of a more frank and regular communication
between public actors. It also emphasizes the benefits of a coordination of efforts and
strategies, something that was eroded in the transition from government-led policies
to a new paradigm of local-based adaptive governance.
Whereas the articulation of public actors is often easy to address by increasing
communication and coordination, conflicts involving private landowners and
developers may be much complicated by the threat of litigation. The lack of a strong
legal backing to public environmental protection mandates is a major obstacle to
shoreline planning around the Bay and elsewhere, and this is highlighted by the
extreme caution of some public agencies in upholding their jurisdictions over private
property. Environmental NGOs have, in the case of California, a big role to play, as they
are able to resort to the same legal and lobbying instruments as the developers, and
may help even-out the field between public stakeholders with limited legal and
economic resources, and powerful private developers with nothing to lose. There is
seemingly a sense of urgency in pushing for the development of shoreline properties,
as public opposition to development on locations exposed to SLR is most likely to
increase in the coming decades. At the same time, NGOs and public agencies are aware
of the stress wetlands will be under as the rates of SLR increase towards the end of
the century.
“Green”, or ecosystem-based, adaptation is already on the way around the Bay. Large
scale wetland restoration projects have already been concluded, and further action
now often requires articulation with the reinforcement of flood defense structures,
given the level of urban encroachment. While levee setback, or removal, would
provide greater environmental benefit, the need to protect urban areas and
infrastructure has led to the trial of ingenious solutions for promoting wetland
resilience while upgrading the level of protection granted by levees.
3
To my mother.
i
CONTENTS
Abstract........................................................................................................................................................... 1
Contents.......................................................................................................................................................... ii
List of Tables ................................................................................................................................................. v
List of Figures ............................................................................................................................................... v
List of Acronyms......................................................................................................................................... vi
Acknowledgments .................................................................................................................................. viii
1
urbanized Estuaries and sea-level rise ....................................................................................... 1
1.1
Estuaries........................................................................................................................................................ 1
1.1.1
Estuarine ecology ................................................................................................................................. 1
Salinity ..................................................................................................................................................................................... 2
Sediment ................................................................................................................................................................................. 2
Tidal range ............................................................................................................................................................................. 2
Habitat connectivity .......................................................................................................................................................... 3
1.2
Urbanization of estuaries ....................................................................................................................... 3
1.2.1
Brief history of the urbanization of estuaries ........................................................................... 3
1.2.2
Recent evolution ................................................................................................................................... 6
1.3
Anthropogenic influence and the emergence of environmental protection ..................... 6
1.3.1
Impacts of human activity ................................................................................................................. 6
1.3.2
Metropolitan estuaries and the rise of the environmental movement .......................... 8
1.3.3
Current Issues in the management of urbanized estuaries.............................................. 11
Wetland restoration ....................................................................................................................................................... 13
1.4
Sea level rise: how much, by when?................................................................................................ 15
1.5
Problem statement: Metropolitan estuaries and Sea-Level Rise ........................................ 19
References ................................................................................................................................................................ 22
2 Evolution of Two Urbanized Estuaries: Environmental Change, Legal Framework,
and Implications for Sea-Level Rise Vulnerability ...................................................................... 29
2.1
Introduction.............................................................................................................................................. 29
2.2
Materials and methods ......................................................................................................................... 31
2.2.1
Reconstruction and mapping of Environmental Histories ............................................... 31
2.2.2
Analysis of planning literature and legal documents ......................................................... 32
2.3
Results ......................................................................................................................................................... 33
2.3.1
Environmental histories of the estuaries ................................................................................ 33
The Tagus Estuary ........................................................................................................................................................... 33
The San Francisco Bay ................................................................................................................................................... 35
Comparison ........................................................................................................................................................................ 38
ii
2.3.2
Legal Context ....................................................................................................................................... 40
Lisbon and Portuguese Law ........................................................................................................................................ 40
San Francisco and United States Law ..................................................................................................................... 42
2.4
Discussion .................................................................................................................................................. 45
2.4.1
Property and land use in estuarine lowlands ........................................................................ 45
2.4.2
Environmental protection standards and the concept of “high water line”.............. 46
2.5
Conclusion ................................................................................................................................................. 47
References ................................................................................................................................................................ 49
3 A tale of two estuaries: Governance, environmental planning, and adaptation to
sea-level rise in San Francisco and Lisbon..................................................................................... 58
3.1
Introduction.............................................................................................................................................. 58
3.2
Materials and methods ......................................................................................................................... 61
3.2.1
Reconstruction of Environmental Histories and vulnerability to sea-level rise ..... 61
3.2.2
Documentation and Analysis of Key Players and Plan Development .......................... 62
3.3
Results ......................................................................................................................................................... 63
3.3.1
Environmental histories and resulting land-use patterns of the estuaries ............... 63
San Francisco Bay ............................................................................................................................................................ 63
The Tagus Estuary ........................................................................................................................................................... 64
3.3.2
The Planning Instruments and Planning Processes ............................................................ 66
San Francisco Bay ............................................................................................................................................................ 66
The Tagus Estuary ........................................................................................................................................................... 68
3.3.3
Comparing Conservation and Sea-Level-Rise Adaptation Efforts ................................. 71
Conservation efforts ....................................................................................................................................................... 71
SLR adaptation .................................................................................................................................................................. 74
3.4
Discussion .................................................................................................................................................. 77
3.4.1
Land use challenges in face of rising seas................................................................................ 77
3.4.2
San Francisco Bay Plan and environmental governance................................................... 78
3.4.3
Tagus Estuary Management Plan and environmental governance .............................. 80
3.5
Conclusions ............................................................................................................................................... 81
References ................................................................................................................................................................ 82
4 Emerging conflicts in implementing green sea level rise adaptation: think globally,
solve locally? .............................................................................................................................................. 89
4.1
Introduction.............................................................................................................................................. 89
Complexity of local adaptation .................................................................................................................................. 89
The expanded role of local governance ................................................................................................................. 90
Emerging conflicts in local adaptation: intractable conflicts or intractable stakeholders? ........... 91
iii
4.2
Materials and methods ......................................................................................................................... 92
4.3
Results ......................................................................................................................................................... 93
4.3.1
Adaptation studies and programs in the San Francisco Bay Area................................. 94
Federal Level ..................................................................................................................................................................... 94
Partnerships between federal, state, and local institutions ......................................................................... 94
State level ............................................................................................................................................................................ 95
Local level............................................................................................................................................................................ 95
4.3.2
Charleston Slough .............................................................................................................................. 96
4.3.3
Redwood City Saltworks ................................................................................................................. 99
Jurisdictional determination under the Clean Water Act ........................................................................... 100
4.3.4 Adapting to adaptation: restoration standards require changes to Bay protection
standards ........................................................................................................................................................... 102
BCDC’s discomfort with rubber-stamping fill .................................................................................................. 103
4.4
Discussion ............................................................................................................................................... 103
4.4.1
Public vs. Public ............................................................................................................................... 104
4.4.2
Public vs. Private ............................................................................................................................. 105
4.4.3
Private vs. Private: for-profit vs. non-profit ........................................................................ 107
4.5
Conclusions ............................................................................................................................................ 107
References ............................................................................................................................................................. 109
Appendix A – Sea-Level Rise Mapping for the San Francisco Bay ......................................116
Appendix B – Sea-Level Rise Mapping for the Tagus Estuary ..............................................124
Appendix C – Comparison of areas rendered below SLR in San Francisco Bay and
Tagus Estuary ..........................................................................................................................................129
iv
LIST OF TABLES
Table 1 – Global mean temperature change and mean sea-level rise according to each
emission concentration path scenario............................................................................................. 16
Table 2 – Statistics for the SF Bay and Tagus Estuary. .............................................................. 30
Table 3 – Sources used for the reconstruction of environmental histories. ..................... 32
Table 4 – Characteristics of the San Francisco and Tagus estuaries. ................................... 60
Table 5 – Data sources used in the flood mapping of both estuaries. ................................. 61
Table C. 1 – Land area of each classof land use rendered below each step of SLR above
current MSL (in hectares) – San Francisco Bay .........................................................................130
Table C. 2 – Land area of each classof land use rendered below each step of SLR above
current MSL (in hectares) – Tagus Estuary .................................................................................130
LIST OF FIGURES
Figure 1 – Miletus (center of image), a major port city during the Hellenistic Period,
relied on its strategic site on the natural harbor created by the Meander River’s
estuary. ........................................................................................................................................................... 4
Figure 2 – Ortelius interprets Thomas Moore’s description of Utopia. ................................. 5
Figure 3 – Side-by-side context maps showing both estuaries at the same scale and
locations mentioned in the text. ......................................................................................................... 29
Figure 4 – Environmental history of the Tagus Estuary. .......................................................... 33
Figure 5 – Environmental history of the San Francisco Bay. .................................................. 36
Figure 6 – Chronograms tracing the evolution of land cover in estuarine low lands of
the Tagus Estuary and San Francisco Bay. ..................................................................................... 39
Figure 7 – Definition of Public Trust/Public Domain and additional planning mandates
in the Tagus Estuary and the San Francisco Bay. ........................................................................ 42
Figure 8 – Urbanized landfill, reclaimed farmland, and cancelled projects (~1850~2000). ........................................................................................................................................................ 43
Figure 9 – Maps of the San Francisco (a) and Tagus (b) estuaries shown at the same
scale, showing locations referred to in the text. .......................................................................... 59
Figure 10 – Complexity of the planning systems......................................................................... 66
Figure 11 – Entities involved in the management of Bay shorelines (Nature reserves
and public open spaces). ....................................................................................................................... 72
Figure 12 – Entities and numbers involved in the South Bay Salt Ponds and the
Samouco Salt Ponds Restoration Projects...................................................................................... 74
Figure 13 – Cumulative area of Wetlands, non-artificial, and artificial areas rendered
below mean sea level with sea level rise, in SF Bay and the Tagus Estuary. .................... 75
Figure 14 – Map of the San Francisco Bay, with locations mentioned in text. ................. 91
v
Figure 15 – Map of the Charleston Slough and surroundings. ............................................... 96
Figure 16 – Map of the Redwood City Saltworks.......................................................................100
Figure 17 – Levee with ecotone zone. ............................................................................................103
Figure A. 1 – Flood Map of the San Francisco Bay - Current situation at ~0 m (MSL)117
Figure A. 2 – +1 m above current MSL ...........................................................................................118
Figure A. 3 – +2 m above current MSL ...........................................................................................119
Figure A. 4 – +3 m above current MSL ...........................................................................................120
Figure A. 5 – +5 m above current MSL ...........................................................................................121
Figure A. 6 – +10 m above current MSL ........................................................................................122
Figure A. 7 – +25 m above current MSL ........................................................................................123
Figure B. 1 – Flood Map of the Tagus Estuary - Current situation at ~0 m (MSL) .......125
Figure B. 2 – +1 m above current MSL ...........................................................................................125
Figure B. 3 – +2 m above current MSL ...........................................................................................126
Figure B. 4 – +3 m above current MSL ...........................................................................................126
Figure B. 5 – +5 m above current MSL ...........................................................................................127
Figure B. 6 – +10 m above current MSL ........................................................................................127
Figure B. 7 – +25 m above current MSL ........................................................................................128
LIST OF ACRONYMS
APA
Agência Portuguesa do Ambiente (Portuguese Environment Agency)
ARH
Administração de Região Hidrográfica (Hydrographic Region
Administration)
BCDC
San Francisco Bay Conservation and Development Commission
CDFW
California Department of Fish and Wildlife
CDWR
California Department of Water Resources
CWRCB
California Water Resources Control Board
CWA
Federal Clean Water Act of 1972
EEA
European Environment Agency
EPA
United States Environmental Protection Agency
vi
EVOA
Espaço de Visitação e Observação de Aves (Bird Watching Center)
FEMA
Federal Emergency Management Agency
HAT
Highest Astronomical Tide level
ICS
Inner Charleston Slough (Mountain View, CA)
IPCC
Intergovernmental Panel on Climate Change
MHW
Mean High Water level
MLW
Mean Low Water level
MSL
Mean Sea Level
NOAA
National Oceanic and Atmospheric Administration
NRC
United States National Research Council
RCP
Representative Concentration Pathway
RHA
Federal Rivers and Harbors Act of 1899
SBSPRP
South Bay Salt Ponds Restoration Project
SF Bay
San Francisco Bay (including San Pablo and Suisun Bays)
SFEI
San Francisco Estuary Institute
SFRWQCB
San Francisco Regional Water Quality Control Board
SLR
Sea-Level Rise
SPUR
San Francisco Planning+Research Association
UNEP
United Nations Environment Programme
UNSAP
United Nations Scientific Advisory Panel
USACE
United States Army Corps of Engineers
USFWS
United States Fish and Wildlife Service
WFD
European Water Framework Directive (Directive 2000/60/EC)
Y.B.P.
Years Before Present
vii
ACKNOWLEDGMENTS
Entering a PhD program at a place such as Berkeley sounded a bit too daunting at first.
It was the support and warmth of the Faculty that made the long road leading to this
dissertation a little easier to navigate. Matt Kondolf is guilty of having me believe I
could do this in the first place, and it was only through his relentless encouragement,
his knowledgeable coaching, and precise editing that the present dissertation came to
be. He is also an incredible person. It was, and will be, a privilege working with him,
and an even greater one having him and his family as friends. Louise Mozingo had to
work double-duty, not only in incessantly keeping me on-track with dissertation
writing, but also in providing crucial council through the (frequent) moments of selfdoubt. Her dedication to the students at LAEP, as a mentor and teacher, is staggering
and inspiring. Vince Resh is one of the most engaging teachers I’ve ever had – ask
anyone who has heard him explain the process through which parasite wasps explode
their hosts in mid-air. He is also exceedingly kind. Several other folks at the Faculty
made this possible, especially John Radke, Michael Southworth, and Richard Walker.
I am deeply grateful for the generous and frank collaboration of all the 16
stakeholders interviewed while researching the topic. The open-mindedness and
knowledge which all willingly shared was most inspiring and encouraging, and
without their insights this dissertation would (literally) have not been possible.
Dealing with distance was made much easier through the efforts of old and new
friends I made in Berkeley. My fellow PhD students, David De La Peña, Sara Jensen,
Allison Lassiter, Zan Rubin, Ye Kang Ko, or Kristen Podolak, are awesome people and
brilliant minds. Raymond Wong, besides being all that, was also paramount not only in
introducing me to real Dim Sum, but also in providing fundamental input to the last
chapter of this dissertation. Still in the Department, Jessica Ludy, Ricardo Sousa, Tami
Church, Rachael Marzion, Catherine Sherraden, Karuna Greenberg, Rosie Jenks and
Bill Eisenstein, among so many others, kept me sane through the workload and homesickness, as did my good friends at the I-House: Aravind Unni, Antón Fernández de
Rota, André Alt, and Sebastião Macedo. I will miss our endless talks over (bad)
breakfast, lunch and dinner. A special thank you is due to Sebastião for kindly taking
care of the bureaucracy necessary to remotely file the dissertation.
Finally, my special thanks go to my family in Lisbon, especially my father, sister, and
aunt. My grandfather Joaquim was a beacon and will be sorely missed. And Susana
dealt with distance and saudade with stoicism, support, and love, worthy of a muchbetter book than the present one.
PhD research was funded by the Portuguese Foundation for Science and Technology
(FCT), through its multi-year PhD Grant (Bolsa SFRH/BD/76317/2011). The first two
years studying at Berkeley were made possible by the generous Pinto-Fialon Multiyear Fellowship, of UC Berkeley’s Portuguese Studies Program, with additional
funding from UC Berkeley’s Normative Time Fellowship and UC Berkeley Beatrix
Farrand Fund of the Department of Landscape Architecture and Environmental
Planning.
viii
1 URBANIZED ESTUARIES AND SEA-LEVEL RISE
1.1 Estuaries
An estuary is “a partially enclosed body of water formed where freshwater from rivers
and streams flows into the oceans, mixing with the seawater” (McLusky 2004).
Estuaries go by several names, and this leads to some ambiguity over what constitutes
an estuary. Via the definition, the wide San Francisco Bay is certainly in an estuary, but
it is only part of a much larger system that also includes the San Pablo and Suisun
Bays and may include part of the Sacramento-San Joaquin Delta. But an estuary can
also be ‘simply’ the terminal stretch of a river, long and usually only gradually
widening, as is the case with the Thames downstream from London or the Elbe,
downstream from Hamburg. An estuary can go by several names: river (Thames), bay
(San Francisco), harbor (Sydney), sound (Seattle), ria (Faro); while in the first
situation the estuarine transition from river to open sea is not entirely perceptible in
that the river’s morphology does not change dramatically (except for the tidal regime
and salinity), in others, the estuary might easily be considered as a mere inlet of the
sea (although there is mixing of fresh and saltwater and land-borne sediment yield).
For clarity, I will be concentrating mostly on large, urbanized, estuaries with a clear
sense of enclosure but that are also evidently wider than the river upstream.
Examples of such estuaries are the San Francisco Bay, the Tagus Estuary (Lisbon,
Portugal), or the Swan River estuary (Perth, Australia).
1.1.1 Estuarine ecology
Estuarine habitats are considered “some of the most productive areas on earth”
(Kennish 1992: 119), ranking at the same level as coral reefs and mangrove swamps.
And elevated productivity is maintained because of high nutrient levels in both
sediment and water column” (McLusky 2004: 1). They form fundamental stepping
stones along major flyways, especially for wading birds, for which they provide
feeding, mating, breeding, and resting habitat. They also constitute important
nurseries for several fish species, responsible for the health of the fisheries off-shore,
and provide excellent habitat for countless species of birds, macro invertebrates, and
mammals (Costa 1999, Conradson 1982, Brearley 2005, Atkinson 2001). Their
shallow waters and silt mudflats provide the substrate for the fixation of seaweeds,
sea grasses, and the salt-tolerant salt marsh plant succession.
The estuarine ecosystem, in temperate regions, is composed of a few major types of
habitat: the mudflat (underwater except for low tide), the salt-marsh (just above the
daily high-tide, submerged frequently in neap tides) and the coastal prairie (low-lying
grasslands, with the saline water table very close to the surface). The man-made saltponds also provide, under certain conditions, good habitat. It is the close succession of
these habitats that constitutes a perfect environment for a vast number of species of
waterfowl. For instance, several wading birds depend on ephemeral lagoons formed
on slightly higher ground for protection, but require the mudflats as feeding grounds.
In estuaries, such environments can be found within close range.
1
Three interrelated major factors appear to control the estuary’s natural functions:
salinity, tidal range, and sediment yield.
Salinity
Estuaries range, by definition, between the salinity of freshwater, always less than 0.5,
and that of seawater, about 35 to 371 (McLusky 2004: 2). Water with salinity within
these limits is called ‘brackish’. The area where the mixing of saline water and
freshwater occurs is usually quite spread, in temperate zones. In these regions, where
freshwater inflow is greater than evaporation, salt tidal water inflows near the bottom
and progressively mixes with fresh water that circulates nearer the surface.
Circulation patterns can be very uniform, in linear, relatively narrow estuaries
(Thames, Severn) or can be characterized by more complex patterns of vertical mixing
and horizontal recirculation of water, as affected by the Coriolis force, in wide
estuaries (San Francisco Bay, Tagus Estuary)2. These circulation patterns also affect
significantly the distribution and deposition of sediment, especially finer sediment
carried in suspension.
Sediment
Estuaries are depositional zones at the lower end of watersheds. As sediment
transport is a direct function of velocity, where rivers flow at fast to moderate speeds,
they are able to transport coarser sediment but, when they reach the lower plains
where they form estuaries, they lose speed. While the top end of an estuary may still
receive larger pebble or sand material, only the finer silts and clays are kept in
suspension and recirculated around the estuary. A usually even greater input of very
fine sediment is received from the sea via the tidal currents (McLusky 2004: 9). These
combined suspended loads are then slowly deposited by the effect of slackened
currents where the river and tidal currents meet, usually in the calmer middle and
upper reaches of the estuary. Here, they form the substrate of the highly productive
intertidal zone.
Tidal range
The circulation patterns mentioned before are deeply dependent on the tidal range of
the estuary (after McLusky 2004): in macrotidal (4-6m amplitude) or hypertidal
(>6m) estuaries, tidal currents can be extremely powerful and impede the fixation of
stable flats; likewise, the depth of water in high tide is unsuited for saltmarsh
1
Salinity is expressed in Practical Salinity Units, a dimensionless unit (McLusky 2004:3)
2
McLusky builds on Fairbridge and Davidson et al (1991) to identify 9 types of estuary. Among these
are the Fjord (narrow, deep interior, shallow mouth); Rias (drowned river valleys, strong marine
influence: Rias of northwest Iberia); Coastal plain (drowned, shallow and wide, river valleys:
Chesapeake Bay); Complex (similar to Coastal plain, but affected by complex topography, driven by
glaciers or tectonic activity: San Francisco Bay, Tagus Estuary).
2
vegetation (such as spartina) to develop; as such, macrotidal estuaries are
characterized by very large, barren, mudflats. Although devoid of vegetation, they are
still abundant with macroinvertebrates and provide excellent habitat form wading
birds. Mesotidal (2-4m) estuaries are composed by the more characteristic succession
of three biotypes: mudflat (drowned in high-tide); wide saltmarsh, dominated by
spartina associations, which provide excellent habitat for water fowl and mammals;
and low-lying coastal plains. Microtidal (<2m) estuaries typically host narrow but
very stable intertidal zones.
Habitat connectivity
A few recent studies have addressed the issue of habitat connectivity in estuaries as a
major determinant on the global health of the fish populations (Herzka 2005,
Meynecke 2007): in ecologically impaired estuaries, the reduced level of connectivity
and proximity of nurseries affect the yield of the fisheries; unlike in terrestrial
habitats (that can be fully isolated by development), a patchwork of fragmented
stretches of wetland habitat may still perform collectively as a viable and productive
ecosystem, even if a few of the elements are lost to pollution or landfilling, as all the
different elements remain connected by the estuary (Meynecke 2007). Only the
systematic destruction of habitat or extreme impairment of the water quality can
render estuaries lifeless (McLusky 2004), which arguably instills them with a greater
level of resilience than terrestrial habitats. Wading birds, for instance, often use
different spaces within a same estuary for resting, feeding and breeding, relying on
this highly interconnected network of different habitats.
1.2 Urbanization of estuaries
1.2.1 Brief history of the urbanization of estuaries
The importance of fluvial and maritime transport to the vitality of cities was
primordial throughout most of history. Only recently did the railroad and highway
systems supersede water-borne transport for long-distance trade, and then not for
very long hauls. As such, mercantile cities were virtually always characterized by
having a good port. The port was the gateway to long-distance trade, and longdistance trade was, at different periods in history, the bloodline of the larger urban
centers. This port should constitute a good harbor for sea-faring vessels (if longdistance trade was the raison d’être of the city) and as such good bottoms were
essential to ensure navigability. This meant that these large port cities usually had to
be located within the lower reaches of rivers, under tidal influence, or in natural
harbors.
Although this was already the case with several Phoenician and Greek trade ports
(Figure 1), the emergence of major port cities is best observable as medieval trade
centers transitioned to the mercantile era. Lisbon, Seville, London, Amsterdam,
Antwerp, and later Liverpool, Boston, New York, San Francisco, Shanghai, Sydney…
The list of major port cities located at the tidal, sheltered harbors of estuaries is vast.
3
And a few of the factors determining the location and expansion of cities in estuaries
remained remarkably consistent throughout history.3
Figure 1 – Miletus (center of image), a major port city during the Hellenistic Period,
relied on its strategic site on the natural harbor created by the Meander River’s
estuary. As the harbor became silted-in, likely due to major changes to the land-cover
of the Meander’s watershed, the port became unusable, and the city lost its purpose.
(Image by Eric Gaba, Wikimedia Commons:Miletus_Bay_silting_evolution_map).
For the idealized capital of Utopia, Thomas Moore settled for a location at the furthest
inland point along a major river that would allow a port for sea-faring vessels London springs to mind as the inspiration (Figure 2).
3
Hart (2001: 91): “San Francisco Bay is a harbor, a place to shelter and to anchor, to moor, to load and
unload ships. It was the harbor that brought the Spanish and then the Americans here. It was the
harbor that made this a metropolitan region. Even today, the harbor is a major support for the regional
economy. (…) Yerba Buena Cove (…) had special advantages. Here mariners found a combination rare
in these parts, deep water close to a gentle shore.” (Morris 1979: 207) The Phoenicians had selected a
similar location, next to an embayment on the north shore of the Tagus Estuary, where they founded
Lisbon, 30 centuries before.
4
This location, at the upstream limit of the estuary where tidal influence still permits
sea-faring ships to navigate, is akin to that of London, Hamburg, or Seville, Spain,
which is located about 70 Km inland along the Gualdalquivir estuary (UNEP 2004).
The dominance of these port cities over entire regions arose from their control over
long-distance trade, but other factors determined earlier settlement around estuaries.
For a start, estuaries are usually surrounded by, or at the extremity of, large alluvial
plains, with very fertile soils. As such, agriculture is typically highly productive in
these regions, and estuarine cities were natural trade centers for this regional
agricultural surplus. In some cases, the rich biodiversity of the region also provided a
wealthy source of food and income, and hunting was a far-from-insignificant activity
in the early stages of the settlement of New York and San Francisco (McCully 2007,
Hart 2001). Also, being located at the confluence of river and sea, these port cities
acted as command centers and transfer points: for the river-based transport, through
which they dominated the natural hinterland formed by the watershed; for the longdistance, sea-based, trade, through which these large ports exported the goods
produced by the hinterland and transformed in the city; and, especially, as gateways
between the “global” and the “local” trade systems.
Figure 2 – Ortelius interprets Thomas Moore’s description of Utopia and places the
capital city at the most central location along the major river that would allow the
creation of a seaport. (Wikimedia Commons:File:Utopia.ortelius).
5
1.2.2 Recent evolution
As technologies evolved, trade increased, and ships grew in size, port areas changed.
First from a rather informal beach landing with a row of warehouses towards
organized port infrastructure, with wide piers or docks extending further and further
into the shores, reaching out for deeper waters (Meyer 1999). Port authorities became
dominant institutions with land-use rights over vast stretches of estuarine shores
(Brown 2008). These land-uses typically took full advantage of extensive landfilling
and dredging, the impacts of which will be analyzed further ahead.
The already pronounced detach between urban areas and the estuary was often
aggravated by the introduction of linear transport infrastructure, first the railroad,
then the highways. In the end, the cities (now mostly metropolises) that had benefited
from the port to achieve greatness, had lost their umbilical connection to the harbor.
Tucked behind the girdle of two or three layers of infrastructure, cities now grew
according to the expansion of inland transport infrastructure (first along railroad
lines, then sprawling with the web of highways). The metropolitan center shifted
steadily away from the port and original business center, as did residents.
Metropolitan estuaries (estuaries and the metropolitan areas than surround them)
generally experienced the same trends in metropolitan evolution as other
metropolitan regions. The driving forces of suburbanization (to use a neutral term)
have been at work, with cities vastly expanding, shifting in scale, and changing their
economy (Beuregard 2006). Having exploded in the United States, after the creation of
the highway system, during the 50s and 60s, the process is ongoing. In Europe, after a
slow start, the post-war era witnessed a steady onset of a new suburban model,
although typically at a different scale and with different housing types (Southworth
1996). Sprawl has paved over entire regions, in Atlanta, Los Angeles or San Francisco,
but also around several European cities (Bosselmann 2008).
1.3 Anthropogenic influence and the emergence of environmental
protection
1.3.1 Impacts of human activity
Estuaries are especially vulnerable to pollution, as the patterns of circulation and
enclosure tend to entrap and re-circulate pollutants over a longer period of time,
where they would be dissipated over time in open coastal environments and along
rivers. Kennish (1992) and McLusky (2004) list the different sources of pollution and
their specific impacts over estuarine ecology.4 These range from chemical pollutants,
degradable or organic enrichment.
4
Oil pollution is perhaps the most visible and infamous of these. Kennish (1992) cites the examples of
Buzzard’s Bay, MA oil spill, in 1969 (8 years of significant disturbance to the environment), and
Chedabucto Bay, Nova Scotia, in 1970 (significant concentrations could still be detected 10 years after
the spill). Frighteningly, these spills account for only about 25% of the total oil that reaches sea, as most
6
Several estuarine environments were subjected to widespread contamination from
chemical pollutants and heavy metals, from industries, nitrogen and phosphorus, from
agricultural runoff, or organic matter, from urban effluents. Needless to say that the
combination of the three activities in the most explosive concentrations occurred in
urbanized estuaries: here, the typical combination of a heavily cultivated agricultural
hinterland and the encroachment by densely populated and industrialized port cities
led to a generalized disruption of the natural environment, through direct destruction
of habitat (filling, dredging), chemical and organic pollution, and introduction of exotic
species. Also, being located at the downstream end of watersheds, pollutants floated
down streams or carried in suspension tend to be trapped in the estuaries’
recirculation and large quantities of heavy metals and other hazardous pollutants are
affixed to the fine particles that deposit on the intertidal flats.
Turbidity, which is naturally dependent on the quantity of suspended fine particles on
the water column, can prevent sunlight from penetrating deep into the water column.
In estuaries that have experienced organic enrichment by urban and agricultural
runoff, the reduced sunlight is a crucial limiting factor for phytoplankton growth, and
potentially toxic algal blooms can be averted in highly impacted estuaries. In
sediment-starved estuaries5, turbidity is reduced and, as frequent blooms occur,
anoxia ensues, triggering mass die-offs along food chain. The ‘dead zones’ thus created
are some of the most gruesome and visible results of anthropogenic modification of
estuarine ecology.
Fortunately, estuaries show signs of great resilience to pollution6: being naturally
unstable systems (with highly variable current systems, temperatures, salinity,
seasonal variation…), several of the species have adapted to withstand some degree of
disturbance and still thrive. Nevertheless, the stress level to which some estuarine
ecosystems have been subjected once appeared beyond recovery and without major
changes to the management of watersheds and pollution control, a quick rebound is
contamination is derived from industries, river and urban runoff (45%), and about 8% from normal
operational losses of the shipping industry.
5
Estuaries typically receive large sediment inputs from their watersheds. If the watercourses are
blocked by dams or weirs, or if the amount of water diverted for human use is such that the capacity of
the river to transport sediment is reduced or annulled, the input of sediment can be severely reduced.
(Kondolf 1997, 2001, Barnard 2013, Schoellhamer 2013)
6
The Thames estuary degraded to the point of full anoxia, in the 1950s, caused by heavy inputs of
domestic sewage; treatment of effluents, starting in 1964, permitted a remarkable ecosystem recovery
and, as the oxygen content in the water slowly increased, the fish diversity in the estuary bounced back
from zero (!) fish species caught in the Thames, for the period 1920-60, up to a remarkable 120, by
2002. (McLusky 2004: 104)
7
unlikely. Particularly in the case of morphological modifications to the estuary,
through landfilling or dredging, recovery without human intervention is often
impossible. This type of direct and often irreversible impact is especially pervasive
around heavily urbanized ‘metropolitan’ estuaries, where port activities, heavy
industry, or garbage dumps, have long been encroaching upon the estuarine
shoreline.7
In these estuaries that host large ports, the number of introduced exotic species is
typically very high. They are, literally, shipped-in and released along with ballast
water, and often cause severe disturbances to the ecosystem (Brearley 2005: 122,
McLusky 2004). An extreme example, “the San Francisco Bay is the most altered
aquatic ecosystem in the United States. More than 250 nonnative species of plants and
animals have taken hold”, and pressure from environmental groups has just recently
led to the EPA being judicially mandated to regulate the discharge of ship ballast along
the coasts. (Walker 2009: 119).
1.3.2 Metropolitan estuaries and the rise of the environmental movement
These recent environmental protection efforts are the natural evolution of a process
that started over 50 years ago. As rivers before them, estuaries were for long
perceived as inexhaustible dumping grounds (McLusky 2004: 95) and sources of
unlimited bounty; not unlike the shocking extinction of the passenger pigeon8, the
possibility of large estuarine ecosystems facing a similar fate served as a potent wake7
Lisbon started early, landfilling a small inlet on the north shore of the Tagus Estuary in the early
middle ages, to build a new quarter, the ‘Baixa’. San Francisco Bay, likewise, was «(…)intensively used
and sorely abused after the 1849 Gold Rush. The State of California wasted no time in turning over to
private owners the entire shoreline and intertidal zone, which thereafter became the exclusive province
of docks, factories, railroads, and warehouses.» (Walker 2009: 110). Over 80% of the historical extent
of wetlands around the San Francisco Bay have been lost to development (Goals Project 1999), and
roughly the same percentage was lost around the New York/New Jersey Estuary (Montalto 2004).
Perth has all-but-eliminated the wetlands around the Swan Estuary (Brearley 2005), converting them
mostly to residential, recreational, and industrial uses.
8
“The passenger pigeon was so pervasive in the early 19th century so as to be considered an
inexhaustible supply of cheap food. They are considered to have been the most abundant bird in the
world and formed the largest flocks of birds ever recorded, only to be exterminated within less than a
century. Audubon witnessed the flyover of one such flock in Ohio in 1813, and pondered that, even with
all the hunting, “nothing but the gradual diminution of our forests can accomplish their decrease”. He
was wrong. Shacking trees so as to cause the nests, and the delectable chicks therein, to fall to the
ground, or organizing massive shootings of flocks, did the trick and the last passenger pigeon died in a
Zoo 101 years later” (McCully 2007: 130-131).
8
up call for environmental protection: that the ecosystem of bodies of water so vast as
the Chesapeake and San Francisco Bays could be degraded close to the point of no
return, was so alarming that they spurred environmental activism: “as the [San
Francisco] bay reached its nadir in post-World War II era, a political movement broke
out to save it in the early 1960s. Saving the bay was one of the first mass, popular
mobilizations on behalf of the natural environment, here or anywhere in the world.”
(Walker 2009: 110-111)
The publication of the infamous Reber Plan9, culminating half a century of widespread
land filling of the San Francisco Bay (Conomos 1979), triggered a chain of events that
would change environmental protection and activism, not only in the Bay, but the
whole country.10 The publication of a map by the Corps depicting the possible extent
of fill resulting from the Reber Plan, in the Oakland Tribune, led a group of three
women of the East Bay elite to initiate a movement to stop further filling11 of the Bay.
Save the Bay was started in 1961 and quickly gathered public and political support
that led to the passing of a State-mandated moratorium on filling and the creation of
the Bay Conservation and Development Commission, through 1965’s McAteer-Petris
Act. The BCDC has, to this day, regulated all projects proposing modification or filling
of estuarine habitat and has successfully prevented significant loss of wetlands since
its creation (Walker 2009).
The fight for San Francisco Bay, along with the perhaps even more staggering
appearance of the infamous Chesapeake Bay’s dead zones in the 1970s12, helped pave
9
This plan (Price 2002) proposed the damming of the San Francisco and San Pablo bays, and led to a
study by the US Army Corps of Engineers (USACE) that predicted that by 2020 70% of the Bay was
suitable for land-filling. See also Section 2.3.1 and Figure 8.
10
In an unprecedented decision, USACE reviewed the project under a presidential mandate. For three
years, the Army Corps conducted simulations of the effect of the two dams over the hydrologic system
of the Bay and Delta. Obvious by today’s standards, maybe not so by 1960s ones, the Army Corps
reached a decision in 1960 that no further testing was necessary; they concluded that the plan’s
consequences were unacceptable, and specifically mentioned the grounds for rejecting it: “It would
adversely affect the unique ecosystem.” (Price 2002).
11
The publication of this map in the Oakland Tribune, led to the three initiators of Save the Bay
reprinting the map under the title Bay or River?. It was mailed-out to 1,000 houses as an incredibly
effective recruitment tool (Walker 2009).
12
Nitrogen and phosphorus pollution of the Chesapeake Bay are at the origin of algal blooms that
deprived large areas of the estuary of oxygen. This leads to mass die-offs up the trophic ladder, from
sea-grass and micro-invertebrates to crabs and fish. That the largest estuary in the country, covering an
9
the way to the creation of some of US’s boldest environmental protection legislation:
the Federal Water Pollution Control Amendments (later Clean Water Act), of 1972
(Kennish 1992: 388), that included severe limitations to the filling and dredging of
wetlands, and a mandate for a much more rigorous control of pollution of all waters.
In a similar process, the widespread elimination of wetland habitat around the New
York-New Jersey Estuary (McCully 2007), likely as much as 75-80% of the historic
extent (Montalto 2004), led to the creation of the Meadowlands Commission, in 1968
(Marshall 2004).
Of course, the environmental tribulations of urbanized estuaries are not exclusive to
the United States. The same processes of encroachment and pollution affected
estuaries all over the world. In other developed societies, the process of
environmental protection was equally influenced by the scale of the environmental
impacts experienced by estuaries.
The Swan River estuary, in Perth, Western Australia, still experiences algal blooms
and massive fish die-offs.13 Although there is evidently a lot to be done, the fact
remains that the Swan estuary has been the subject of some of the foremost
environmental protection legislation, due to the visibility of the environmental
impacts of agriculture and encroachment by the metropolitan area of Perth: the first
committee set-up to deal with the purity of water and cleanliness of the estuary’s
foreshore was established as early as 1943, and the Swan River Conservation Act of
1958 established the Swan River Conservation Board. The occurrence of algal blooms
is now being fought through changes to agricultural practices on the whole watershed
(Brearley 2005).
In Lisbon, Portugal, this link between estuaries and environmental awareness and
protection is also present. As early as in 1836, a company was set up to manage
(through what are now considered to be sustainable practices) the vast expanses of
agricultural land, the lezíria, around the Tagus Estuary14 (see Section 2.3.1). The
area only slightly smaller than the State of Connecticut, could be so severely impaired by the combined
effluents from its watershed was a dramatic demonstration of our collective destructive capacity, much
along Garrett Hardin’s argument in The Tragedy of the Commons, published in 1968.
13
The more enclosed nature of the estuary, the reduced surface of water (as compared to the San
Francisco Bay, for instance) and extreme seasonality of the inflows from the Swan-Canning river
system all contribute to occasional flushing of high concentrations of phosphorus and nitrogen onto the
estuary; in an unseasonal storm in January, 2000, this process led to the whole estuary being closed to
all human activity due to a massive bloom of poisonous alga (Brearley 2005: 102).
14
The lezíria is a type of man-made low-lying agricultural land, regulated through a system of canals
and low sustaining walls, that has proven to be a sustainable agricultural practice ever since.
10
intrinsic value of these lands was again recognized in 1964, when a Regional Plan
prevented potential urban development on the best habitat and agricultural land
around the estuary. Although this may not have been an express concern of the plan,
but rather the directing of development towards more suitable land, the result is that
the northeastern part of the estuary was kept in very good condition until the first
natural parks were created, after the Revolution of 1974. Then, once more, the value
of the estuary was asserted when the Tagus Estuary was included in the first group of
Natural Reserves15 created in 1976. Although historically the Tagus estuary has
experienced severe impacts, from agricultural, industrial and urban discharges of
pollutants, the high turbidity appears to have prevented major algal blooms from
occurring (Ramiro Neves, cited in Garcia 2011).
A few major disasters, such as the 1966 accidental spill of 700 tons of sulfuric acid
from the CUF plant, led to the elimination of a few iconic species, such as the
Portuguese oyster, but recent legislation (National and European, see Sections 2.3.1
and 3.3.1) have led to the progressive treatment of all sewage, and the estuary has
been showing signs of recovery. A multi-decade plan to collect and treat all sewerage
around the Tagus Estuary has just been completed. Even before an emblematic urban
sewage collector started diverting the last remaining untreated outlets within the city
of Lisbon to a newly-expanded treatment plant, the improvements to water quality,
not the least from the much-reduced activity of the heavy industries surrounding the
estuary, were already visible and reflected in the growing abundance of fish species
(Garcia 2011, Cabral 2001).
1.3.3 Current Issues in the management of urbanized estuaries
The recent concentration of port activities in large container terminals is releasing
waterfront for redevelopment or restoration. Whether to create business centers or
housing condominiums; provide public facilities, public open space or other amenities
for the populations; or to restore wetland habitat along these coveted shorelines,
becomes the fighting ground between several vested interests, both private
(promoters, land owners…) and public (port authorities, environmental protection
agencies, city governments…) (Meyer 1999, Brown 2008, ULI 2004). The citizens have
gained growing influence: increasingly, the traditional lobbies are now joined, or
fought against, by several environmental or social activist associations, whose
interests range from saving wetland habitat, to the creation of more public open areas,
or the protection of built heritage.
Unique conflicts emerge from clashing interests, even when they could all be
considered in the “public interest”: in Lisbon, the proposed expansion of the Alcântara
15
The Natural Reserve is highest level of importance after the only National Park in the country, the
Peneda-Gerês. The Tagus Estuary Natural Reserve was created by the Decreto-Lei nº575/76 (July 19th),
recognizing its “fundamental and irreplaceable economic and ecological roles” and protecting its
“extreme [biological] richness”, under the Ramsar Convention of 1971.
11
container terminal (publicaly owned, privately operated) generated much opposition
from the residents of a nearby hillside neighborhood, that thought the added
containers would interfere with their views of the river; in New York, NIMBY practices
have turned the implementation of necessary infrastructure into a topic of hot debate
in the new field of environmental justice (Sze 2007); SF Bay is host to several such
disputes. The largest proposed development on former Baylands, the Redwood City
Saltworks, will be further discussed in Chapter 4, as will these emerging land-use
conflicts.
Compromise has not always been the rule of the game and some entities, especially
port authorities, have been less than willing to negotiate in the past. Lisbon Port
Authority was, until recently, still considering a proposal to create a giant jetty over
the Tagus river’s spit that would allegedly decrease the silting of navigation channels,
with little concern over the consequences to the natural environment. Nevertheless,
the greater public involvement has changed, if ever-so-slightly, the decision-making
process and the balance of power: with enough uproar, most proposals that seriously
impact the shoreline now seem growingly subject to compromise and improvement.
The management of estuaries, formerly done according to strictly top-down, sectoral,
and often conflicting perspectives, failed for long to tackle the threats to the estuarine
ecosystem. As of recent, a more collaborative and transparent approach to local
governance, integrating land-use planning and natural resource management, is being
pushed forth in several developed nations. Integrated estuary management plans now
serve as platforms for the promotion of sustainable ecosystem management, pollution
control, and adequate planning of shoreline uses and environmental stressors
(McLusky 2004: 158, BCDC 2008).
So, after a period of profound abuse and neglect, improvements to the environmental
health of estuaries are starting to show, especially in developed countries.16 As
pollution control and sewage treatment are implemented, the water quality will, given
16
“The management of nutrients and carbon inputs has virtually eliminated dead zones from several
systems, including the Hudson and East Rivers in the United States and the Mersey and Thames
Estuaries in England.” (Diaz 2008); in the Chesapeake Bay, the management of sewage and pulp mill
effluents has led to many small-scale reversals in hypoxia, even if overall the system is still
experiencing extreme rates in loss of biomass (mostly sea grass, micro and macro invertebrates).
Jacksonville, NC, has concluded an extremely successful program to clean-up and recover Wilson Bay
through what looked as a desperate attempt at re-introducing oysters to the heavily polluted system:
“The oysters did not simply live. They thrived. (…) As the oysters filtered the detritus and consumed it,
the water became cleaner and as it became cleaner, the benthic community reestablished itself. That
attracted fish, which in turn attracted birds. Soon even sea otters splashed in the bay.” (Moore 2009:
88).
12
time, improve dramatically. If the destruction of wetland habitat is equally halted,
estuaries seem to possess an excellent capacity of self-healing.17
Wetland restoration
Larger wetland restoration efforts have spread around several estuaries. In the San
Francisco Bay (Williams 2001), and the South Bay Restoration Project is the largest
tidal wetland restoration project on the West Coast of the United States. Specific
interventions range from relatively simple actions on degraded habitat so as to
restore lost functions, to more complex projects to create these wetlands from scratch.
These interventions could be qualified as the creation of artificial wetlands. The Goals
Project (1999) assessed common causes of (technical) failure, frequent in some of
these restoration efforts:
- Inability to re-create all of the functions of a natural marsh;
- unrealistic design, siting or size;
- the requirement to undertake mitigation on the same site as the development
impact often resulted in mitigation projects being sited in disturbed or
marginally suitable locations;
- a lack of clear or realistic objectives frequently made it difficult to determine
whether a wetland project was a success or failure (to which Kondolf (2000)
and others would append the need for post project appraisal and monitoring).
The San Francisco Bay has, to a large extent, functioned as a testing ground for
wetland restoration, but experience has allowed some of the earlier mistakes to be
corrected. The efforts of habitat restoration are now a welcome and integral part of
the process of ecosystem recovery that the San Francisco Bay has been going through
(see Chapter 4).
There has been an ongoing debate over the relative merits of environmental
restoration. Nassauer (1995) reminds that ecological function and naturalness are not
17
«The environmental movement to save the bay reversed a century of degradation. Since the Bay
Conservation and Development Commission has been established in 1965, the bay has shrunk no
further and has had hundreds of acres of wetlands restored. Its waters are no longer rank, and aquatic
life is abundant, with shorebirds in large number feeding along the mudflats and marshes. Most
important, the nay is now seen as a vast scenic, recreational, and ecological open space, instead of a
dour transportation hub and industrial landscape. Some 180 of 275 miles of bay shoreline are now
open to the public, compared to only 5 miles when the blue-green revolution began. The bay has come
back as the visual centerpiece of the metropolis, a watery commons for the region, and a source of pride
to Bay Area residents.» (Walker 2009: 111).
13
necessarily synonymous, as Nature is a social construct: restoring ecological function
is (or should be) the purpose of environmental restoration, but should not be
confused with design criteria, at least not in the aesthetic sense of design. The
‘neatness’ expected from the ‘well-kept’ landscape is often not present in strictly
functional projects; although these are likely to perform well in the ecological
dimensions, they might be misinterpreted as ‘failures’ by a less-informed observer,
because they lack visual ‘cues’ that attest their validity and performance.18
Mozingo (1997), reinforces this point, and proposes ways through which ecological
designs can incorporate principles of landscape design so as to make them ‘readable’
to an observer.19 By introducing a few common elements of landscape design,
restoration efforts may be made not only ecologically, but also socially valid.
Especially in artificial wetlands, that create habitat rather than restore it, there should
be a preoccupation as to the didactic value of the intervention, by incorporating
features that make the ecological function an enjoyable sight (something as simple as
interpretation signs and clear ‘gateways’ may do a lot to improve this…).
Wetland restoration in metropolitan estuaries has some specific merits, in that it deals
with a rather ‘wild’ natural feature within a highly artificial environment. Estuaries,
when not completely degraded, are the largest ecologically functional ecosystems
within their metropolitan regions, somewhat subverting the historical push towards
the dichotomy between Man and Nature as incompatible realms. Cronon (1995)
brilliantly argues that the romantic quest for the unspoiled and idyllic wilderness
might prevent the urban dweller from perceiving, and thus valuing, the wildness at the
door-step.20
Restoration efforts may easily fall into the trap of the ‘technological solution’ that
renders bad habits ‘sustainable’: in his much-misunderstood critique of restoration,
Katz (1992) ends up highlighting this crucial point: «we are not restoring nature; (…)
18
Nassauer (1995: 248): «The general design principle we can use to guide design and policy is to label
ecological function with socially recognized signs of human intentions for the landscape, setting
expected characteristics of landscape beauty side by side with characteristics of ecological health».
19
Mozingo (1997): «Ecological designers may presume that the ecological value of a landscape will
speak for itself. (…) What is visible is the surface manifestation of ecosystems and the material
conclusions of ecological process. (…) The ready perception of the surface features of ecological
systems (…) suggests the particular importance of access and pathway to create viewpoint and contrast
in ecological design. (…) where and how the ecological and the cultural interact should be obvious and
celebrated.»
20
Mozingo (1997) sums it up: “A land ethic born from a wilderness vision inevitably leaves the city as
wilderness’s discomfiting and degraded opposite.”
14
Nature restoration is a compromise; it should not be a basic policy goal. (…) it cleans
up our mess. We are putting a piece of furniture over the stain in the carpet, for it
provides a better appearance. As a matter of policy, however, it would be much more
significant to prevent the causes of the stains. » If there is a perception that all errors
might be remedied, the underlying principle of restoration as an improvement of the
damaged natural function (Atkinson 2001) might be put in jeopardy by a less acute
sense of cause and consequence.
This warning seems particularly adequate to the climate change debate: just as
restoration efforts are starting to spread throughout the developed world, sea-level
rise threatens to drown the new wetlands, along with the original ones and quite a
few of the low-lying urban areas… Idly standing by, in face of this challenge, is simple
not an option.
1.4 Sea level rise: how much, by when?
The scientific debate over SLR has long moved from whether it is happening, and it
now focuses on the determination of rates of sea level rise, spatial variability in sea
level elevation and what factors affect this. The challenge now is increasing the
accuracy in determining local impacts/effects of rising sea levels.
The latest IPCC report establishes a range between 0.26 to 0.55m as likely if major
progress is achieved in curbing emissions, and 0.52 to 0.98m in the projected worstcase scenario (IPCC 2013: 13-14, Table 1). The same report concludes that, based on
current understanding, “only the collapse of marine-based sectors of the Antarctic Ice
Sheet, if initiated, could cause global mean sea level to rise substantially above the
likely range during the 21st century. This potential additional contribution cannot be
precisely quantified but there is medium confidence that it would not exceed several
tenths of a meter of sea level rise during the 21st century.” (IPCC 2013, pp.13-14).
While not entirely reassuring, the report, which is for the most part an aggregation of
scientific research, sets a manageable timeframe for adaptation for most developed
nations. The survivability of island nations, or the odds some types of wetland
ecosystems will have in adjusting to the rates on the high end of the spectrum, are still
major challenges, even if unclenching of polar sheet ice is averted.
As of late (past decade), the IPCC and UNSAP have been adopting a cautious approach
to the form of communication of scientific data and results, a ‘calibrated language’ to
express the confidence in and/or likelihood of specific findings. This is most effective
when there are a very large number of contributions, so as to allow for a quantitative
assessment of confidence and uncertainty. The shift in the style of results
communication is especially evident in the transition from IPCC’s AR4 (IPCC 2007) to
AR5 (IPCC 2014).
Even under this very cautious approach, IPCC communicates that further sea level rise
past 2100 is nevertheless inevitable, and paleo sea level records indicate that sea level
exceeded 5m above present when global temperature was up to 2ºC warmer than preindustrial:
15
«Cumulative emissions of CO2 largely determine global mean surface warming by
the late 21st century and beyond. Most aspects of climate change will persist for
many centuries even if emissions of CO2 are stopped. This represents a
substantial multi-century climate change commitment created by past, present
and future emissions of CO2 (...) A large fraction of anthropogenic climate change
resulting from CO2 emissions is irreversible on a multi-century to millennial time
scale, except in the case of a large net removal of CO2 from the atmosphere over a
sustained period.» (IPCC 2013, SPM-15).
Table 1 – Global mean temperature change and mean sea-level rise according to each
emission concentration path scenario (IPCC 2013: SPM-2).
So, even under IPCC’s cautious assessement, we have already committed to several
centuries of SLR, which could represent up to 5m above current MSL. Uncertainty may
hinder the capacity or willingness of policymakers to advance adaptation agendas and
spur active adaptation measures, but what is known is defenitively not an impediment
of resolute action, in the eyes of the European Environmental Agency:
«The lack of perfect information is a common feature in all areas of
policymaking. Uncertainties must not prevent taking decisions but it is in the
interest of policy-makers to be aware of the degree of uncertainty associated with
specific data sources so that they can consider the range of plausible
developments in their decisions. The importance of uncertainties about climate
change and its impacts for a particular decision depends on factors such as the
time horizon and reversibility of the decision, the importance of climate factors
for the decision, and the costs of buffering the decision against uncertain
developments. For example, when uncertainties are very large, it is often (but not
always) prudent to focus on ‘no regrets’ and ‘win-win’ adaptation strategies that
address adaptation to (uncertain) climate change jointly with other societal
goals, thereby limiting the additional cost of the adaptation component.» (EEA
2012b: 43)
Sea-level rise (SLR) has been described as a “slow moving emergency” (Gordon 2014).
It challenges common perceptions of what constitutes a natural disaster in more than
one way. It is, for the most part, a consequence of anthropogenic actions, but not
16
directly so: Climate Change can now reliably be attributed to human action (IPCC
2014), but the mechanisms through which this global change produces SLR are far
from simple and are still not fully understood (IPCC 2013, IPCC 2014). What is known
is that SLR has been happening at an accelerated rate for at least a century, and will
accelerate in the near-future (NRC 2012). Also consensual is the idea that past
emissions of greenhouse gases alone will produce effects over the global sea level for
several centuries.
This concept is, in itself, a major challenge to common perceptions of impending
“danger”. Crisis and risk management are often closely associated with a sharp
awareness of the risks of inaction, or protracted action. Every time a flood hits a
floodplain, for instance, it helps reinforce a notion that people might already have, and
most policy and planning officials are most likely aware of: there is exposure to a risk
(EEA 2012b:45), that vulnerability is often recognized (EEA 2012b, Adjer 2006), and
people have a few reliable ways to avoid it, if they are willing to so (EEA 2013). SLR
itself, on the other hand, is a new challenge, and is yet to express itself fully in a way
that renders it obvious to the general public. People are unable to process
hypothetical scenarios in the multi-generational scale, which makes it hard to
communicate danger and make the issue a relevant one for policy-makers.
The early “doomsday” communication techniques, where the scientific community
conveyed the full extent of SLR’s plausible impacts with abandon, were not entirely
successful in transmitting the message to the general public (Feinberg 2011). It is, in
this respect, a problem more closely resembling that of communicating the risk of a
very large earthquake striking a given area: they are usually devastating events, but
might have a recurrence interval of a few centuries. Finding the right balance between
raising unnecessary alarm and letting the issue fade into oblivion is often challenging
for the scientific community and decision-makers: too many “false alarms” might
expose scientific knowledge to (often unfair) challenges, in a “boy-who-cried-wolf”
type of situation; too little, or too infrequent, communication of the risk renders it
virtually unknown to the general public.
Precision is essential: using the term “global warming” rather than “climate change”,
while equally correct, exposes scientific knowledge to uninformed attacks such as the
typical “how come the planet is warming up if there’s an epic blizzard out there?!”
type of argument (Schuldt 2011, Whitmarsh 2008). Yet, a little cunning could go a long
way. While SLR is, for the most part, “invisible”, the extreme climate can be very easily
associated to it, and the aftermath presents an opportunity to inform the general
public while climate is under the media spotlights (IPCC 2012, Carey 2011).
In fact, it is now evident that two extreme storm events – Katrina, in 2005, and Sandy,
in 2012 – were paramount in mainstreaming SLR adaptation into US media and
political agenda (Tollefson 2012). It could be argued that the latter, in particular,
while having had a (fortunately) reduced death toll, was particularly effective in
conveying the message, as it struck US centers of power and decision-making. This is a
cynical, yet pervasive, issue: the “it could happen to us” is still an exceedingly powerful
concept, and “us” often means narrowly those with power.
17
While the political environment in 2005 and 2012 should necessarily be taken into
account, it is obvious that the media attention granted to storm surges was
fundamental in raising awareness to coastal hazards. In the words of John Laird,
Secretary of California’s Natural Resources Agency:
“the situation is not a bathtub where there is only gradual rise. (…) it is the 2-year
old child jumping into the bathtub, which is the extreme event. And it is the
extreme event that will especially drive the message home on what sea-level rise
is and what its effects are on the coast.” (Gordon 2014:4)
To be absolutely rigorous, extreme events such as hurricanes or epic surges did occur
before late Holocene climate change was unclenched; it is the frequency with which
the most extreme events occur that is alarming (IPCC 2012, Birkman 2010). Be it as it
may, climate change and its impacts are finally in the public agenda for most
developed (and quite a few developing) nations, and coastal zone management is
deserving of a special attention.
This may not only be related to the media attention surrounding the impacts of recent
storm events (such as Sandy and the 2013-2014 Winter Storms in the Atlantic Coast of
Europe), but also to an increasing awareness that most of the damages and casualties
can be attributed to more or less crass planning and policy choices: risk21 is a function
of hazard and exposure; simply put, if a huge hurricane strikes an unpopulated or
extremely well prepared/protected shoreline damage will be minimal, in the same
way a major earthquake in Japan or in Haiti will have vastly disparate impacts.
Planning mistakes of today may prove exceedingly expensive in the near-future.
In the very definition of the word vulnerability, which can be directly correlated to
risk, the human component is evident: vulnerability is “the quality or state of having
little resistance to some outside agent; the state of being left without shelter or
protection against something harmful” (Merriam Webster). While the hazard itself is
often uncontrolable, risk may be averted or mitigated (namely through risk avoidance
strategies, including removing vulnerable structures or setting up efficient evacuation
strategies), and vulnerabilities can be addressed through proactive adaptation
(increasing the sturdiness of built structures, protecting valuable or strategic assets in
the more exposed areas) (IPCC 2012). Given that the hazard itself, in the case of
coastal storms, is a more or less uncontrollable variable, the mitigation of risk lies
precisely in reducing the level of exposure to it – by addressing current vulnerability.
This recognition of past mistakes, while far from easy, is essential as a trigger for
change. Change in policy, legal standards, and land-use/planning practices. Riskavoidance strategies often entail, over flat and exposed coastlines, dramatic shifts in
21
Very intersting takes on this issue come, unsurprisingly, from those agents dealing with insurance
and security: http://www.pinkerton.com/blog/risk-vulnerability-threat-differences;
http://www.threatanalysis.com/2010/05/03/threat-vulnerability-risk-commonly-mixed-up-terms/
18
long-standing practices and cultural attitudes. The perseverance and willingness to
rebuild displayed by local populations along the Mid-Atlantic US coast after Sandy
stroke, while certainly worthy of praise, may be ill-advised: the level of exposure to
risk along those sandy (no pun intended) coastlines would demand a thorough and
honest weighing of the benefits and the risks of rebuilding, in place where one is,
scientifically speaking, certain another disaster will fall.
The issue with exposed coastlines is not whether a major event will occur, but rather
how often and how big that event will be. And climate change’s contribution to an
exacerbated risk is two-pronged: there is a growing consensus that the frequency and
intensity of storms may increase in the future; and the elevated eustatic sea levels
expected in the future will increase the hazard they present to any given coastline.
1.5 Problem statement: Metropolitan estuaries and Sea-Level Rise
Metropolitan estuaries combine characteristics that make them especially vulnerable
to sea-level rise: they host large expanses of low-lying alluvium, located just above
current MSL; vast expanses of these lowlands are often occupied with urban areas and
infrastructure along the shorelines; and urban development has encroached upon
(and severely disturbed) wetlands, which are highly sensitive to fluctuations in sea
level. As such, the threat of SLR is a very real and eminent prospect in these settings
(Diez 2011).
The potential losses (economic, social, and ecological) to SLR could be astronomical
(Ericson 2006, Heberger 2009, EEA 2012a and 2012b, ANPC 2010, Strauss 2012), as
many of these metropolitan estuaries are characterized by having their most valuable
assets located on, or near, the waterfront. The level of exposure of central business
districts, historic centers, and crucial infrastructure, such as ports and airports, makes
adaptation to SLR a matter of survival for these cities.
The costs of early adaptation to SLR have been assessed by different sources to be
much smaller than the future costs of hasty reaction (EEA 2013, Gordon 2014,
Pendleton 2008, RAE, n.d.). As such, several of these metropolitan areas have begun to
address this threat through regional planning and some local adaptation actions.
As urban areas, vital infrastructure, and irreplaceable wetland habitat would, in their
present condition, be severely affected by sea-level rise, inaction is no longer an
acceptable attitude. The possibility of protecting urban areas and infrastructure
simply through the construction or reinforcement of levees would in all likelihood
prove to be but a temporary solution, as sea-level is expected to keep rising far
beyond the estimates for the year 2100.
Also, some of the more radical technological solutions might in fact contribute to
worsen the flooding problems elsewhere, as is often the case with heavy-engineered
coastal protection: besides conveying a sense of false security that may encourage
further development behind these structures, introducing levees or sea-walls might
contribute for sediment starvation along non-protected shoreline and increase the
energy of tidal currents and storm surges over unprotected areas. A more resilient
19
attitude could consider planning in advance for the progressive relocation of crucial
urban functions and infrastructure to higher ground, allowing the existing and
expanded wetlands to work as natural buffers against the ever-more-frequent storm
surges (Beatley 2009, Titus 2011, SPUR 2011).
Walker et al (2004) define resilience as “the capacity of a system to absorb disturbance
and reorganize while undergoing change so as to still retain essentially the same
function, structure, identity, and feedbacks.” This definition draws on Holling’s previous
work and is expanded by Beatley (2009). Although the concept of resilience may be
ambiguous, this precise definition perfectly fits the vision of a sustainable, viable,
metropolitan estuary in face of ever-changing conditions: Sea-level rise may produce
irreversible modifications to both urban and natural environments around estuaries,
but there seem to be solutions that would allow for the vital functions of both to be
retained. Heavily-engineered technical solutions, such as sea-walls and levees, may
help protect vital urban infrastructure, but the consideration of passive approaches,
such as the planned withdrawal to higher ground, and the protection and expansion of
wetlands, could help preserve crucial habitat and also act as a damper preventing
direct impacts from storm-surges (Goldie 2006, IPCC 2007, SPUR 2011, Titus 2011).
For that to happen, estuarine ecosystems demand special attention. As mentioned
before, these ecosystems have experienced severe disruption from anthropogenic
action. Just as they are showing signs of improving health in developed countries with
higher environmental protection standars, they are now faced with a big challenge
from SLR. Most salt marshes will likely be unable to keep up to future rates of SLR
unless proactive action is taken so as to enhance their capacity of accretion22 or to
permit their slow migration upland (Middleton 2012, Woodroffe 1990, Morris 2002,
Temmerman 2003, French 2006, D’Alpaos 2007, Kirwan 2007, 2010, Mudd 2009. See
also Chapter 4). Within urbanized settings, armoured shorelines make this an
especially tasking exercise.
Accretion (the vertical growth of wetlands, in response to higher water levels) is
improbable if the rate of rise is too fast. Only the perfect combination of high inputs of
sediments from the watershed and the presence of plant species already adapted to
high variability (those in estuaries with meso- or high-tidal ranges) can reasonably be
expected to keep up with rising sea levels. For the highest rates of SLR being
considered towards the end of the century, only the migration of wetlands would
preserve them.
22
«Wetlands are generally able to keep up with moderate rates of sea level rise by accreting (building
up in place). There are two major processes of accretion: organic build-up and mineral sediment
trapping. (...) the response rate of accretion to varying degrees of sea-level rise is poorly understood,
leaving open the question of when a wetland surface may become unstable due to insufficient sediment
supply and organic matter accumulation, [is] commonly referred to as the threshold of resilience.»
(Middleton 2012: 86)
20
This would be possible only where gentle slopes inland from their current extent are
unobstructed by man-made barriers, such as levees, highways or railroads (Goldie
2006, Bird 1993). Wetland preservation is thus possible under the more conservative
estimates of sea-level rise (IPCC 2007: 329, Allen 1995, Bird 1993, Chmura 1992,
Krone 1985, Morris 2002, Reed 1990, 1995, Simas 2001, Temmerman 2003, see also
Section 4.3.4), but incompatible with urban encroachment without significant
measures, wich could include the relocation of existing urban development (Goldie
2006: 251-258, BCDC 1987, 2008, IPCC 2007, SPUR 2011).
The following chapters take as case studies two metropolitan estuaries sharing
striking morphological and climatic similarities – San Francisco Bay and the Tagus
Estuary in Lisbon, Portugal – to analyze how they have evolved and which may be the
underlying causes for their diverse development patterns (Chapter 2), how the
environmental governance structure works and how it has been addressing more
exigent environmental standards and incorporating SLR (Chapter 3) and, finally, what
are the emerging conflicts and opportunities arising from local adaptation (Chapter
4).
21
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28
2 EVOLUTION OF TWO URBANIZED ESTUARIES: ENVIRONMENTAL
CHANGE, LEGAL FRAMEWORK, AND IMPLICATIONS FOR SEALEVEL RISE VULNERABILITY
A version of this chapter has been submitted for review to
The Holocene (Print ISSN: 0959-6836)
2.1 Introduction
The estuaries of the Sacramento River, California (San Francisco Bay) and of the Tagus
River in Portugal (Figure 3) share many commonalities in topography, hydrology, and
climate. Both face threats from accelerated sea-level rise, but the exposure of urban
areas to rising waters is significantly greater in San Francisco Bay than in the Lisbon
Estuary (as will be discussed in Chapter 3). In this paper, we explore differences in the
historical evolution of these two estuaries, and key divergences in the legal and
institutional histories, such as the degree to which tidelands have historically been
treated as public lands, how the ‘high-water’ limits of public trust are defined, and
how the public trust zone migrates with coastal erosion. We argue that these
differences can largely explain the contrasting situations in which the two estuaries
find themselves as they confront sea level rise.
Figure 3 – Side-by-side context maps showing both estuaries at the same scale and
locations mentioned in the text.
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The San Francisco Bay, California (henceforth, SF Bay), is the largest estuary along the
west coast of North America. The Tagus Estuary, Portugal (henceforth, the Tagus
Estuary), is the largest estuary on the Atlantic coast of Europe (Table 2). With an area
of ~1260 km2, SF Bay is significantly larger than the Tagus Estuary, ~320 km2 (EPA
2011, APA 2013). Both provide critical wetlands habitat along major flyways and are
crucial as nurseries replenishing fish stocks offshore (Okamoto 2011, Catry 2011,
Costa 1989, Costa 1999). Both SF Bay and the Tagus Estuary are surrounded by large
metropolitan areas, with the San Francisco Bay Area being, with a population of about
7 million, the second largest metropolitan area on the Pacific coast of North America,
and the Lisbon Metropolitan Area, with about 3 million inhabitants, being the largest
urban center located directly on the Atlantic Coast of Europe. Geomorphologically,
both estuaries are “drowned valleys”, marked by alternating episodes of active
incision during ice ages and marine transgression during warm periods (McLusky
2004). Thanks to rock type and active tectonics, both estuaries have “bottlenecks” at
their mouths, with wide inner basins and inland deltas. The Mediterranean-type
climates of both estuaries results in large seasonal and inter-annual variability in
precipitation and fresh water inputs.
Table 2 – Statistics for the SF Bay and Tagus Estuary.
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2.2 Materials and methods
2.2.1 Reconstruction and mapping of Environmental Histories
We reconstructed the environmental histories of both estuaries, drawing upon
primary such as historical maps and documents, and modern paleogeographic
reconstructions (Table 3). Map sources were scanned, georeferenced, and processed
on GIS software to delineate shorelines and identify (when possible) wetlands, urban
areas and infrastructure. It is important to note that older map references (e.g. Seco
1561, Cañizares 1776) did not adhere to current standards in terms of their accuracy
and projection. These sources provide important information (regarding the existing
of more than one branch on the Tagus delta, for instance) but the delineation of the
features therein should be regarded as an approximation. Therefore, the maps for
12,000 BP, 4,000 BP and 1000 BP should be interpreted as well-informed
approximations, rather than accurate depictions. For San Francisco Bay, we analyzed
historical maps such as Cañizares (1776), Duflot de Mofras (1844), Cadwalader
Ringgold (1850), Britton & Rey (1874), as well as landscape reconstructions such as
Anderson (2013a, 2013b), which provide valuable information on the status of the
estuary before and at the onset of European settlement. We also drew upon
reconstructions of past geography and bathymetry by Schoellhamer (2013), Kirwan
(2011), Goals Project (1999), Watson (2013), Atwater (1977, 1979), Wright (2004),
Okamoto (2011), and Knight (2014), which provided information on the patterns of
post-glacial flooding of the estuary, and the emergence and expansion of wetlands. For
the Tagus estuary, we analyzed prior studies of historical change and
paleostratigraphy (especially the exceptional work of Vis (2008), but equally with
inputs from Martins (2010), Schriek (2007), Leorri (2013), Dias (1997), Fletcher
(2007), and Uribelarrea (2003)), and complemented them with the abundant
information provided by historical maps (such as Seco (1561), Gendron (1757), Eça
(1767), Cabral (1790), Costa (1809 and 1813), Lamotte (1821), Silva (1847), Lopes
(1930, 1945), and Instituto Hidrográfico (2012)), and historical documentation of
land-use (Companhia das Lezírias 1839). We used historical data compiled by
Beirante (1998), Madaleno (2006), Soares (2011), and studies of historical and
modern distribution of wetlands (Vale 1987, Gameiro 2007, Ribeiro 2003, Taborda
2009). Additionally, we combined map data from NASA (2010), Goals Project (1999),
USGS (2006) and IGP (2007) with the information on wetland distribution from the
previous sources in mapping the current situation.
Each reconstruction was assembled as a project in GIS software and we retrieved the
area of each of the following categories: permanently flooded, corresponding to open
waters of the estuary; wetlands, corresponding to the extent of mudflats, oyster , and
saltmarsh; drained for farmland corresponds to the conjectural extent of wetlands and
permanently flooded areas that were converted onto farmland; diked ponds is the area
of former wetlands and open waters that were diked for the creation of salt ponds;
and landfilled for urban development corresponds to those areas of landfill which were
developed as large infrastructure (such as ports, airports, transport and other
infrastructure corridors, refuse disposal), industrial, commercial or residential areas.
From these values, we created chronograms tracing the relative percentage of each
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category in relation to the maximum extent of estuarine lands before disturbance
(corresponding to the scenario for ~4,000 Y.B.P.).
Lisbon
Maps
San Francisco
Other documents
Maps
Schriek 2007, Leorri
2013, Fletcher 2007
Atwater 1977, Atwater 1979
Other documents
Smith 2011, Okamoto 2011,
Barnard 2013
Smith 2011, Barnard 2013,
Vis 2008, Dias 1997, Taborda 2009,
Schriek 2007, Leorri
Atwater 1977, Atwater 1979 Goman 2008, Okamoto 2011,
4000 YBP (Figs 2b & 3b)
NASA 2009
2013, Fletcher 2007
Anderson 2013b
Goman 2008, Barnard 2013,
Seco 1561, Gendron 1757, Eça 1767, Beirante 1998, Martins
Watson 2013, Atwater 1979 Kirwan 2011, Watson 2013,
1000 YBP (Figs 2c & 3c)
Vis 2008
2010, Fletcher 2007
Anderson 2013a and 2013b
Gendron 1757, Eça 1767, Cabral
Goals Project 1999, Duflot
Martins 2010, Peixoto
Kondolf 2008, Swanson 1975,
ca. 1800 (Figs 2d & 3d) 1790, Costa 1809 and 1813, Lamotte
de Mofras 1844, Atwater 1979,
Matias 2010
Anderson 2013a and 2013b
1821, Silva 1847, Vis 2008
Watson 2013
Developed landfill and
Kondolf 2008, Swanson
Silva 1847, Lopes 1930 and 1945,
20th century projects
Costa 1999, Duarte 2013 Watson 2013, BCDC 1998
1975
COS 2007, Instituto Hidrográfico 2012
(Figs 6a &6b)
COS 2007, Instituto Hidrográfico
Current Situation (Figs
Martins 2010, Duarte
2012, NASA 2009, Vale 1987, Ribeiro
Goals Project 1999
Kondolf 2008, Swanson 1975
1a, 1b, 2e & 3e)
2013
2003, Gameiro 2007, Taborda 2009
12000 Years Before
Present (Figs 2a & 3a)
Dias 1997, Vis 2008
Table 3 – Sources used for the reconstruction of environmental histories.
2.2.2 Analysis of planning literature and legal documents
We reviewed past and current legal standards, contained in laws and planning
documents, and compared them with historical land-use changes. This allowed for a
critical analysis of the historical adherence and detach between theoretical planning
standards and the actual outcomes in terms of land-use changes, especially regarding
reclamation, expansion of landfills and shoreline development. For historical law
doctrines and standards our main sources for the Tagus Estuary were Beirante
(1998), which lists a number of precedent-setting court decisions predating the mid1800s Portuguese Civil Code ( including King John I v. Gonçalo Velho (1410)), and
Cândido de Pinho (1985). For more recent standards for the definition of the Public
Domain and delimitation of the high water line used in its definition, we referred to
Rilo (2014) and Assembleia da República (2005). The later also provides indication of
the current doctrine regarding erosion & avulsion. Moniz (2011), and APA (2013)
document the Tagus Estuary Management Plan’s regulation and objectives, and are
complemented by recent news regarding environmental standards and enforcement
of Public Domain law (Garcia 2014, Soares 2014). For the SF Bay, we consulted
references on the Public Trust Doctrine (Sax 1970, Lazarus 1985, Eichenberg 2009,
2013, Cech 2010, McGinley 2013, The Crown Estate n.d.) and complementary
information on the doctrine regarding erosion & avulsion (Ruggiero 2001, Caldwell
2007, Sax 2009, Glasscock 1993). We also analyzed documents regarding the specific
institutional and legal arrangements around the San Francisco Bay (Dolezel 1971,
Luken 1974, Briscoe 1979, City of Berkeley v. Superior Court 1980, Davoren 1982,
Berke 1983, BCDC 2011, Johnson 2013).
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2.3 Results
2.3.1 Environmental histories of the estuaries
The Tagus Estuary
The Tagus Estuary was created after the end of the last glacial period, when the rising
sea level drowned the lower Tagus River valley (Dias 1997, Vis 2008). After being
drowned by the rapid post-glacial sea level rise, the inland delta of the Tagus grew
through sediment deposition, and sediment further accreted along the margins of the
estuary, establishing tidal wetlands.
Figure 4 – Environmental history of the Tagus Estuary: a) situation of the narrow
estuary ~12,000 Years Before Present, following the Last Glacial Maximum; b) ~4,000
Y.B.P., after the rate of SLR stabilized, the estuary began to fill, and wetlands became
established at sheltered and upstream sections; c) ~1,000 Y.B.P., after at least one
millennium of settlement around the estuary and along the basin, increased sediment
inflow and prograding delta, with reclamation already occurring along tributaries and
margins on the upper delta; d) ca. 1800 most of the reclamation of the delta and
consolidation of the lezírias was complete, but the river still displayed remnants of its
former anastomosing delta; e) Current situation. Wetlands are now mostly confined to
the widened middle section of the estuary, and the remnant river branches have been
transformed into regulated irrigation channels. Urbanization and infrastructure has
taken over most of the right bank along Lisbon, Oeiras, and some south bank
municipalities. Along the eastern edge of the estuary, the largest expanse of mudflats
and marshes is set against farmland, with very limited urban development. The South
Bank hosts small but important marshes, heavily encroached by urban development.
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The evolution of wetlands and settlement around the Tagus estuary was one marked
by repeated cycles of reclamation of the coastal prairie that formed behind the
advancing (“prograding”) pro-delta situated at the upstream section of the estuary; as
the frontline of mudflats and saltmarsh accreted and moved downstream, it created
behind it a large floodplain of fertile soils, which were seized and used for agriculture
by all the successive civilizations that controlled it, from the Romans to the Visigoths,
on to the Moors and, eventually, the Portuguese. This special kind of low-land,
reclaimed farmland, traditionally protected by low walls or stakes, along the lower
Tagus valley, is called the “lezíria”. The term derives from the Arabic al-jazīrah,
meaning island, and referred to depositional islands, point bars, and tidal flats along
the river channel. Later, it came to be synonymous with the alluvial plain as a whole.
Although accurate descriptions of the estuary are lacking before formation of the
Kingdom of Portugal in the mid-12th century, some documents hint that there was
already a practice of draining the lezírias for farmlands before then (Beirante 1998,
Schriek 2007). The modification of the watershed and virtual extirpation of primeval
forests was completed before the end of the Middle Ages (Fletcher 2007, Uribelarrea
2003), resulting in greater influx of sediment onto the estuary, which likely
accelerated the rate of wetland expansion and extent of potential lezírias farmland
(Figure 4c).
The Tagus went through periods of avulsion of the main channel (natural process
through which the river abandons a channel and switches to another) and, by the late
middle ages, there were at least three channels running parallel, with two of those
preserved as navigation canals running parallel to the main course. Historic names for
branches, or arms, in the lower Tagus - Tejo Novo (New Tagus), Tejo Velho (Old
Tagus), Tejinho (Little Tagus) – indicate that its anastomosing nature lasted until
relatively recently (Beirante 1998: 774, Martins 2010: 27) and this is reproduced in
some historic maps. No defined main arm is indicated on the map of Seco (1561), and
the “Old Tagus” is still identified on maps as late as the 18th century (Eça 1767, Cabral
1790, Lamotte 1821), showing at least some clearly natural arms of the river running
into what is now the Lezíria Grande island, and showing that there was at least partial
retention of some wetland habitat along the margins of those channels (Figure 4d).
Historical records, such as those presented in Beirante (1998) and Madaleno (2006),
indicate that expansion of farmland through land reclamation was done through
cycles of great commitment, usually encouraged by more enterprising kings (more
land reclaimed, and greater yields, equaled more taxes). These periods of intense
reclamation followed others of relatively lax central power and/or lack of workers
and funds (periods of war, “bad” kings…), during which flood defenses fell into
disrepair, and changes to the estuary’s hydrology due to deforestation, avulsion of the
river’s channels during floods, or fluctuations in sea level and storminess during the
Medieval Warm Period and the Little Ice Age. Protecting farmland against floods and
high tides required the construction and constant maintenance of protective walls,
and insuring the navigability of the river, was a constant struggle (Martins 2010).
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The most extensive efforts of landfilling for infrastructure were related to the
expansion of the Port along Lisbon municipality’s waterfront, between the last couple
of decades of the 19th century and the first three decades of the 20th century (Durão
2012). In total, some 397 ha of fill were created along the already urbanized
waterfront, mostly within the Lisbon municipality. In the mid-20th century, some
areas in the south bank of the estuary were landfilled for the expansion of large
industrial units and port areas (notably the Quimiparque grounds, in Barreiro, the
Lisnave shipyards and Alfeite naval base, in Almada, and the Siderurgia Nacional
complex, in Seixal) but together these areas amounted to only about 236 ha. A further
36.8 ha of localized expansions to pre-existent port areas were added in the first
decade of the 21st century. In total, landfilling for purposes other than farming was
less than 670ha. Industrial areas and large infrastructure occupy virtually all those
areas, with only negligible residential and commercial development. A 1950s plan to
create a large dyke and bridge between Lisbon and Montijo would have presupposed
the reclamation of as much as 8,000 ha of marsh and mudflats for the expansion of the
irrigation project (Figure 8a). Fortunately, the project was postponed and definitively
abandoned for environmental reasons in the 1970s (Costa 1999: 41).
Since the mid-20th century, dams along the mainstem Tagus (in Spain) and on
tributaries (Spain and Portugal) have extirpated anadromous fish runs of more
sensitive species (Batista 2012), significantly reduced the inflow of fresh water onto
the lower estuary, and reduced the sediment loads dramatically to as little as 1/3 of
its prior level (Andrade 2002: 187). Nevertheless, the Estuary still appears to have a
positive sediment balance, with progradation rates of around 1.1 cm/yr (Costa
1999:33). Studies conducted on the Estuary’s marshes estimate that the current
sedimentation rates (4 to 27 mm/yr, depending on the location) will allow wetland
accretion to keep pace with the rates of sea-level rise predicted for the end of the 21st
century (Duarte 2013, Silva 2008, Silva 2013).
The estuary’s water quality was severely compromised by untreated industrial and
sewage effluent, with severe impacts on the estuarine ecosystem (Costa 1999, Caçador
2001). At the turn of the 21st century, the situation improved substantially: the
closing down of major industries and a major program to introduce primary and
secondary sewage treatment along the Tagus river basin, spurred after Portugal and
Spain’s accession to the EU in 1986, allowed a slow but steady improvement in water
quality, increased fish stocks, and the return of some sensitive species (Costa 1999:
164, Soares 2011, Duarte 2013).
The San Francisco Bay
During Pleistocene time, what is now San Francisco Bay was an alluvial plain, across
which flowed the lower Sacramento River, joined by its many tributaries. The rise in
sea level after glacial melting led to the flooding of SF Bay, reaching approximately its
current extent ~5,000 Y.B.P. (Atwater 1977), and slowing to a rate of about
20cm/century. The estuary began slowly filling with sediment (from tributaries and
the mainstem Sacramento), resulting in the fixation and slow expansion of wetlands
from around 4,000 Y.B.P. (Barnard 2013, Goman 2008) with a slightly accelerated
35
expansion during the Little Ice Age (ca. 1550 to ca. 1850) (Watson 2013) due to land
cover changes in the watershed (Anderson 2013 a, 2013b).
Figure 5 – Environmental history of the San Francisco Bay: a) Around 12,000 Years
Before Present, with sea-level much lower than present, the narrow river channel
emptied into the ocean near the Farallones Islands; b) ~4,000 Y.B.P., having filled the
Bay after a few millennia of rates of SLR of about 2 mm/yr, the rate drops by ten-fold
and allows wetlands to become established at sheltered and sediment-rich edges; c)
~1,000 Y.B.P., early human activity around the Bay and the Central Valley have
influenced sediment input, but the pattern of slow accretion and expansion of wetlands
persists; d) ~1,800 Y.B.P., grazing and changes to land cover upstream accelerate
sediment deposition and wetlands expand rapidly; e) Current situation. After one
century marked by much-accelerated deposition due to hydraulic mining, wetlands
expand in the mid-1800s, only to be transformed along their edges into farmland, salt
ponds, and urban areas. Especially along the South Bay and on the north edge of San
Pablo Bay, vast areas remain diked to this day, but recent restoration efforts are
converting most of the former salt ponds onto restored wetlands. Just upland from
these ponds and remaining marshes, most of the farmland has been developed into
commerce, industry, housing and infrastructure, encroaching upon most wetlands.
Around the time the first European settled around the San Francisco Bay, after 1769,
the Bay was still a largely undisturbed natural environment. The few thousands of
Ohlone Native Americans that had long lived around the Bay introduced changes to
36
land cover, from controlled burnings and selective clearing, but likely had minimal
impacts over the environmental performance of the larger estuarine ecosystems
(Figure 5d, Okamoto 2011:108-111). For the most part, the natural succession of
mudflats-low marsh-high marsh-coastal prairie was still present by the time of the
first surveys (Goals 1999) and features prominently in some early maps of the Bay
(Cañizares 1776, Duflot de Mofras 1844, Britton & Rey 1874). This latter element, the
coastal prairie extending just above the highest tides, elusive as it is now around SF
Bay, has likely been absent from the Tagus Estuary in historical times. Suffice to say,
this readily-available provision of alluvial soils just high enough above the saltwater
to allow cultivation was the first victim of large-scale settlement.
Encouraged by policies promoting the draining and filling of wetlands for agriculture,
vast areas of tidal wetland were dyked and drained for farmland, from the 1850s
onwards. From the late 1800s through the 1930s, vast areas of salt ponds were
created at the expense of tidal marshes, with the largest salt-producing company,
Leslie Salt, still owning over 21,000 ha of Baylands as late as the mid-70s (Luken
1974: 140, Okamoto 2011: 133). This was followed by extensive landfilling for large
infrastructure, ports, industrial areas, and even residential neighborhoods, such that
over 90% of the Bay’s pristine tidal saltmarshes had been lost to dredging and
landfilling by 1965 (Goals Project 1999, Williams 2001, Madsen 2007).
The process of reclamation was made easier by parallel changes set off by the
introduction of hydraulic mining in the Sierra Nevada (1852-1884), which increased
sediment loads of the Sacramento River ten-fold (Barnard 2013, Schoellhamer 2013,
Wright 2004), causing rapid accretion of the shorelines and shallowing of the estuary,
making it easier to dredge and landfill vast areas of the Bay’s shorelines. Swanson
(1975) estimates the rates of new landfill at ~414 hectares/year between 1850-1900,
~622 ha/yr between 1900-1925, ~751 ha/yr between 1925-40, and a high of 914
ha/yr from 1940 to 1965, the year when reclamation was effectively halted.
Well upstream from SF Bay, extensive 20th century construction of dams and water
diversions in the Sacramento River basin resulted in reductions in fresh water inflows
to SF Bay, blocked migration of anadromous fish, and trapped most of the natural
sediment load before reaching SF Bay (Okamoto 2011: 138-144). From an estimated
peak of about 10 Mt/yr, average yearly sediment loads from the Central Valley could
be as low as 1-1.2 Mt/yr currently. In fact, now that most of the hydraulic mining
debris has been mobilized all the way down to the estuary, Bay Area watersheds may
currently be delivering more sediment to the Bay that the mighty Sacramento-San
Joaquin system (Barnard 2013) and sediment yields may fall below pre-disturbance
levels. If we consider the accelerated rates of SLR expected for the next centuries, the
survivability of marshes may be in jeopardy (Orr 2003, Watson 2013), as their ability
to keep pace with SLR through accretion is largely dependent on the suspended
sediment load (Stralberg 2011, Swanson 2014).
In the late 19th and 20th centuries, the Bay became heavily polluted by discharge of
untreated industrial and municipal sewage until the closure of many bayside
industries and extensive construction of wastewater treatment plants following
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passage of the state’s Porter Cologne Act of 1969 and the federal Clean Water Act of
1972 (Okamoto 2011: 158-160). Following the passage of the McAteer-Petris Act of
1965 (see next section), landfilling was halted. Wetland restoration efforts have
ensued and, especially since the implementation of Bay-wide ecosystem restoration
targets (Goals Project 1999), the purchase and restoration of several salt ponds has
allowed for a steady increase in the provision of habitat (Williams 2001, Goals Project
1999, Kondolf 2008, Madsen 2007, Klatt 2013) That culminated in the ongoing South
Bay Salt Ponds Restoration Project (SBSPRP 2014).
Comparison
Setting side-by-side the chronograms tracking the evolution of both estuaries, in
terms of the relative percentage of each main category of land cover (Figure 6 a and b)
it is apparent that, while the transformation of the Tagus lowlands has been much
more extensive, former estuarine lowlands lost to urban development stands now at
around 0.8% of the total, whereas 8.6% of the former San Francisco Bay lowlands
have been transformed into urban areas.
The Tagus Estuary has experienced a much longer process of anthropogenic
disruption, and its smaller size lent itself to faster infilling. Therefore, the net loss in
open water surface, as compared to the baseline for the maximum extent of estuarine
lands (approximately the sum of permanently flooded surface and wetlands for the
~4,000 Y.B.P. maps, Figure 4b and Figure 5b) was much greater in the Tagus than in
SF Bay, which remained largely undisturbed until a couple of centuries ago. Compared
to its reconstructed maximum, the Tagus Estuary has shrunk to about 27.8% of its
mid-Holocene maximum, with most of the loss being attributable to millennia of
progradation and consolidation of farmlands before the 1800s. SF Bay experienced an
equally slow process of natural progradation, which led to the creation of extensive
wetlands around its edges. All in all, about half of SF Bay’s maximum extent is still
permanently flooded.
From an environmental standpoint, the most relevant indicator would be the overall
provision of wetlands and similar habitats around each estuary. The Tagus Estuary
was allowed to developed extensive wetlands near its prograding delta has soon as
the rate of sea-level rise slowed down. Nevertheless, as this process has been coupled
with disruption from human activity for at least the last two millennia, the natural
process of wetland expansion was curbed by a simultaneous reclamation of higher
ground, contributing to a slow decrease in total area of wetlands. Although significant,
we reconstruct this reduction to be no greater than half the maximum extent of
wetlands (~290 Km2 to ~144 Km2). From our reconstruction of the estuary’s
environmental history, wetlands may have represented around 35% of total estuarine
area (~290 Km2) around 4000 BPY, but have stabilized at around 20% (~145-150
Km2) throughout the last millennium and stand currently at ~144 Km2 (~18% of total
estuarine area).
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Figure 6 – Chronograms tracing the evolution of land cover in estuarine low lands of the
Tagus Estuary and San Francisco Bay (relative %).
The San Francisco Bay experienced a mostly undisturbed natural process of
progradation from around 4,700 Y.B.P.. with a slow expansion of wetlands and
parallel reduction of permanently submerged area This trend accelerated and slowed
down through a series of loops and feed-backs between regional trends in rainfall and
smaller fluctuations in global sea-level (Watson 2013). With the arrival of European
settlers, in the mid-1800s, the expansion of wetlands is believed to have accelerated
with the increased sediment deposition, first with land cover changes produced to the
Sacramento-San Joaquin watershed from the 18th century onwards, and especially
during the period of hydraulic mining of the late 1800s (Schoelhammer 2013). After a
steady increase in total area of tidal wetlands, reaching a maximum of around 994
Km2 (about 47% of the total estuarine area), the subsequent landfilling and draining
led to a very rapid decrease to ~700 Km2 (~33%) around the turn of 20th century and
as little as ~340 Km2 (~16%) by the mid-1960s. After early experiments in wetland
restoration, large efforts in restoration, focusing especially in the reversion of salt
ponds into managed wetlands, have increased significantly the total provision of tidal
39
or managed wetland provision around the Bay, from the 1960s low-point to about
~475 Km2 (22,6%) in 1998 and nearly 600 Km2 today, close to the Goals Project
(1999) target of about 615 Km2.
2.3.2 Legal Context
The differences in tidal wetland conversion and lowland urbanization patterns
between Lisbon and San Francisco estuaries can be largely attributable to their
different legal traditions and contexts, as we analyze ahead.
Lisbon and Portuguese Law
Grounded on a legal tradition that can be traced back to at least the 6th century with
the Justinian Code, navigable waterways (and, to a lesser extent, their margins) have
enjoyed legal protection under the assumption that they should to be preserved for
the common good. Although not always explicitly stated, for most of history this was
more a mechanism to ensure the Crown or the State’s ability to control, and tax,
waterborne commerce and fishing.
The doctrine regarding erosion and avulsion may be equally old. Once the river
experienced avulsion, typically during larger flood events, abandoned channels or
islands suddenly connected to the margins. In times when the centralized power was
weakened, local municipalities, religious orders, or even neighboring landlords would
often seize the newly-created land. There is ample documental evidence of the efforts
made by several kings in asserting their ownership over those lands, the “lezírias”,
and Beirante (1998) argues that this struggle marked a defining moment in the
affirmation of centralized power in the early centuries of the Kingdom of Portugal.
The long-standing practice of preserving a fringe of wetland is consistent with the
practice of reserving all land below “the December High Waters” for the Crown (that
is, in Public Domain), a measure grounded on the old Roman tradition of a public trust
protecting all navigable waters and floodplains (Cândido de Pinho 1985).
In 1864, all shores subject to inundation at spring-high tide were designated Public
Domain (Royal Decree of December 31st, 1864). Some 30 years before, the Companhia
das Lezírias, then a private society, was created to manage the farmlands belonging to
the Crown Prince. The model of public-led management of the bulk of farmland
located on the alluvial plain persists to this day, and has largely prevented extensive
urbanization of these productive agricultural lands.
Major reclamation efforts would traditionally follow either major flood events or
periods of abandonment. Faced with the Crown’s inability to single-handedly restore
all productive land, the king would often stimulate the rebuilding of flood defenses
and retaining walls by granting temporary deeds to those willing to drain, defend, and
farm the land. From the omnipresence of references to “swamps”, “beaches”, and
“wastelands” throughout historic documentation, it is clear that, even during the
periodic spurts of reclamation, a fringe of lower marsh was present. As elsewhere in
Europe, the navigable waters and shorelines constituted public trust owned by the
40
Crown, and unwarranted alteration or appropriation by private citizens was often the
subject of legal action and generally forbidden.
One particular document, from the early 15th century, is most enlightening in this
respect and indeed produced jurisprudence that carried continuously into present
Portuguese law. King John I (1385-1433) had been, in the first decades of his reign,
particularly active in asserting his right to all swamps and “lezírias”. At first, he
resorted to the traditional Visigoth concept through which “terras ermas” (wastelands
or abandoned lands) belonged to the Crown. In 1410, however, the King successfully
argued in the Crown’s Court that a landlord had illegally occupied land (a beach
located on the banks of the Estuary) that was his by right resorting to a novel legal
mechanism: the river and its banks were both “public in nature” and that the property
(a beach) was once “lezíria” and all “lezírias” were his by right (King John I v. Gonçalo
Velho 1410). The doctrine invoked by the Court to rule for the King explicitly stated
that since the property (was) fully covered with water in January (that is, during the
largest floods), and only dry during the Summer, it indeed belong to the Crown’s
Estate. That Court’s decision established precedent on two crucial aspects: 1) river
banks subject to flooding are to be included in the Crown’s Estate as part of the Jus
Publicum; 2) for that purpose, the highest elevation of floods is to be considered – the
“January high waters”. This decision restored onto common doctrine the old Roman
tradition of “Public Right” (Jus Publicum) to flood-prone beds and banks.
Through different legal ordinations, these standards were preserved and, according to
the fluctuations in the effectiveness and power of the central administration, more or
less upheld. Eventually, these Jus Publicum (corresponding roughly to the American
concept of Public Trust) determinations were codified into the modern civil code
(Código Civil) after 1864. The “Domínio Público”, or Public Domain, as this doctrine
came to be known in Portugal, was then expanded to include a 50m buffer inland from
the high-water mark in coastal waters where only deeds predating the creation of the
Law would be permitted and all new construction or land use transformation would
be severely conditioned. This expanded jurisdiction over margins was quite
innovative at the time and remains one of the most generous in Europe (Andrade
2002:179). In the subsequent 150 years, the Public Domain remained a staple of
Portuguese land law and has arguably been the strongest mechanism for the
protection of coastal resources, the preservation of wetlands, and maintaining public
access to the country’s shorelines.
Among the provisions in the new environmental law, there has been a refinement and
expansion of the protection granted to natural systems, and wetlands now have
specific articles protecting them from destruction or alteration. Wetlands, and all
floodplains, have specific protection under the National Ecological Reserve (DecretoLei nº321/83), but coastal wetlands were, by definition, already included in the Public
Domain. Further expansion of the protective buffer inland from the dominial waters
came with the new Water Law (Assembleia da República 2005) which matured from
earlier legislation the concept of “adjacent zones” in flood-prone or sensitive areas,
extending a limited planning mandate over all land considered as vulnerable to
flooding from river or sea waters.
41
In the specific instance of waters under tidal influence, as is the case with the Tagus
Estuary, the effects of wave run-up are also to be considered as forcing factors when
defining the “highest astronomical tide line” (HAT) that serves as the upper limit for
the “bed”. In the case of the Tagus Estuary, the Governmental Decree authorizing the
Environmental Agency to elaborate the Estuary Management Plan (APA 2013),
established (according to the concept of “adjacent zones”) a planning mandate for a
500m transition zone inland from the upper limit of the Public Domain, which already
includes the 50m-wide “margin” (Figure 7). Furthermore, the national law establishes
that “land lost to the sea” through erosion is to be automatically incorporated into the
Public Domain, and the adjoining buffers realigned according to the new shoreline.
Figure 7 – Definition of Public Trust/Public Domain and additional planning mandates
in the Tagus Estuary and the San Francisco Bay.
San Francisco and United States Law
The United States inherited several fundamental doctrines dating back to Medieval
English Common Law. Among these is the doctrine that preserves the “Jus Publicum”
(the “Public Right”) over navigable waters and flood-prone banks and shorelines.
They are “held in trust” by the State, hence its modern denomination as the Public
Trust Doctrine. It corresponds to the concept of Foreshore (United Kingdom), trusted
to the Crown’s Estate. The Common Law dispositions are themselves distant
derivatives of much older doctrines, and in particular the same Roman Justinian Laws,
themselves derived from yet older legal codes (Cech 2010: 250-255, Slade 1997: xii, 1,
3-5). The aim of this doctrine, as in Portugal, was to preserve natural resources for the
common good (albeit through the upholding of the monarch’s right to control and tax
all uses and foreshore concessions…). The letter of the law includes, for most
countries with a Common Law tradition, a variation of the notion that all navigable
42
waters and lands that are subject to regular flooding (that is, those located below the
high water line) are to be preserved for the public (Lazarus 1985, Eichenberg 2009,
Titus 1998, Sax 1970, Slade 1997). So, in essence, this is a similar concept to that of
the tradition of most European countries, of which the Portuguese Law is an example.
The peculiarities of its practical application, however, derive from the early decision
of American legislature to grant this Trust onto the States, which in turn led to
significant differences between different States’ interpretation and jurisprudence. The
Federal Arkansas Swamp Lands Grant Act (1850) made appropriations of “swamp and
overflowed” lands a prerogative of the individual states. California promoted draining
and filling of wetlands for agriculture, as a way of attracting settlers to the newlycreated State. Importantly, it granted full property titles, rather than temporary
concessions, over reclaimed land, a solution that would later be determined as in
violation of the prerogatives of the Public Trust, over a century later, as will be
discussed further ahead. Between 1855 and 1909, “land” (more often than not,
marshes subject to twice-daily flooding) was sold at auctions for as cheap as $1 per
acre (Luken 1974). The extent of this state support for wetland draining and
landfilling is reflected in the Reclamation Map of 1874, showing all wetlands and most
shallow flats as subject to reclamation (Britton & Rey (1874), reproduced in
Woodbridge (2006)), and even a 1959 US Army Corps map that showed all shallow
waters as potential landfill (reproduced in BCDC (1998: 4) and included in Figure 8b).
Figure 8 – Urbanized landfill, reclaimed farmland, and cancelled projects (~1850~2000).
Another state prerogative was the definition of the landward limit of the Trust. In
shorelines subject to tidal action, the definition of the “high water”, which is crucial in
43
bounding the upper limits of the Trust, is defined by most US States (including
California) by the high water mark (Slade 1997: 6-8). For most purposes, the Mean
High Water (MHW) is considered. It corresponds to the average of all high tides of
each tidal day during a 18.6-year Astronomical Cycle. This means already that the
Portuguese Public Domain extends its protection up to a greater elevation, and thus
typically extends further inland than the Californian Public Trust (Figure 7).
In a legal context more favorable towards the upholding of individual property rights
over common good interests than in most of Europe, the expansion of planning
mandates and the upgrading of environmental law and planning standards has proved
more difficult. This is especially true whenever these new provisions would entail the
imposition of restrictions over the use of private property. In the absence of
systematic evolution of planning and environmental law to adjust to changing social
paradigms and expectations, as was mostly the case in countries belonging to the
European Union, the Doctrine has been used as a proxy for strong environmental
legislation and, since the 70s, it has served as a legal loophole of sorts in natural
resources preservation (Sax 1970). This has led to some criticism over the unnatural
expansion of its scope well beyond the common water resources it initially aimed to
protect. The Public Trust Doctrine has been invoked in cases involving cemeteries, air
resources, or in implementing a State’s hazardous waste control legislation (Lazarus
1985) to the point where it became almost a moniker for public interest in the
protection of natural resources.
The dramatic alteration from natural shorelines to landfilled and dredged urbanized
waterfronts, and even more the threat to completely fill SF Bay as envisioned in the
Reber Plan (Price 2002), had a deep impact on the public and institutions in the SF
Bay region. The Reber Plan’s proposal to fill-in SF Bay, except for a narrow ship canal,
and the ensuing “potential landfill” studies by the US Army Corps (Swanson 1975,
BCDC 1998: 4) shocked many into realizing that such a large and iconic ecosystem
could come under real risk as a result of reckless development decisions (Figure 8b).
Grassroots movements garnered support for the McAteer-Petris Act, passed by the
California legislature in 1965 (Walker 2009). It led to the creation of the San Francisco
Conservation and Development Commission, the first coastal zone management
agency in the United States (Swanson 1975). BCDC was tasked with the elaboration of
the Bay Plan, and gave it full planning powers over areas subject to tidal action (mean
high water or, in tidal marshlands, the inland edge of marsh vegetation up to five feet
above Mean Sea Level). In practice, it was extremely effective in curtailing all major
efforts of wetland “reclamation” (Dolezel 1971), and it reasserted the State’s right to
protect all lands included in its Public Trust. An additional 100ft (~30m) buffer
extending landward from the high water line was included in BCDC’s jurisdiction, but
with no planning mandate other than the ability to impose public access to the shores.
Therefore, the Commission has a very limited capacity to prevent new development
proposed just above the high water (Eichenberg 2013).
Paradoxically, the aforementioned extension of litigation over the Public Trust
Doctrine well beyond its original scope has led to a legal backlash (already foreseen by
Lazarus (1985)): while recently amending the Bay Plan (2009), the BCDC was
44
confronted with resistance from developers and local governments in asserting its
right to manage tidal lands (Johnson 2011). BCDC had to assert that their mandate
extended over Bay shorelines up to the limit of the Public Trust, the MHW, and
therefore encompassed all tidal lands (Eichenberg 2009, Travis 2009). This added
difficulty in expanding mandates and jurisdictions of public agencies is by no means
new, and has been a recurring problem for Bay Area planners (Davoren 1982,
Eichenberg 2013). Given the difficulty in ensuring their current mandate is respected
and acknowledged, a near-future expansion of its planning mandates (so as to
incorporate meaningful buffers upland from this limit) is unlikely and prone to
intense litigation
Nevertheless, being that the Doctrine is tied to a concept of “high water line”, rather
than an actual demarcation, it is now perceived as a plausible mechanism of SLR
adaptation, especially once coupled with another ancient doctrine regarding erosion
and avulsion (Sax 2009, Titus 1998, Glasscock 1993). Combined, they would read as
follows: in episodic erosion caused by natural events or through unforced flooding by
river or sea waters, land lost to the waters would automatically incorporate the Public
Trust. The high water line would accordingly migrate landwards, and so would the
jurisdiction of public agencies, without the need to resort to a typically traumatic
takings clause. This is sometimes called a “rolling easement” (Titus 1998, 2011) and
provides a solid legal basis for BCDC to invoke the “ambulatory nature” of its
jurisdiction (Eichenberg 2009: 263).
2.4 Discussion
2.4.1 Property and land use in estuarine lowlands
The King’s Lands were, in the specific case of the Tagus Estuary, granted to the Crown
Prince’s Estate, and remained so throughout the Middle Ages and until 1836, when the
unified “Herdade do Infantado” (Prince’s Estate) was sold off, in 1836, to a single
corporation, the Companhia das Lezírias. Albeit promoting new irrigation projects and
completing the draining of the Lezíria Grande (the large island that was created
through the consolidation and unification of several former delta islands), the
Companhia das Lezírias kept is focus on agriculture and grazing. Nationalized again in
the 70s, this public company manages to this day the farming on the delta, and several
species have adapted to forage or shelter in the farmlands. Most of the land remains in
public ownership and transmission of full property rights was limited. It remained so
until the introduction of modern legislation specifically protecting the best soils and
floodplains. The result was that most of the lowlands around the estuary remained
construction-free, first through the Crown’s preference to promote profitable
farmlands, helped by the frequent reminders, through major flood events, of the active
nature of the floodplain, then through legislation specifically protecting the wetlands
and farmland.
Around SF Bay, the Arkansas Act of 1850 was used by the State as a means to promote
extensive draining and landfilling. Until the early 20th century, the titles to the “lands”
were sold in auction, and the buyers were granted full ownership of the land. This was
justified based on the need to create new farmland and attract settlers. Later, through
45
the transmission to local city governments, the situation went from bad to worse.
While initially this transference was destined to promote infrastructure
improvements, most cities were unable to resist the profitability inherent to the
transformation of wetland to “fastland”, resulting in as much as a 75-fold increase in
land value (Luken 1974). Vast areas of former tidal lands were therefore transferred
onto private landowners, a practice that is clearly at odds with the principles of the
Public Trust Doctrine (Briscoe 1979, City of Berkeley v. Superior Court 1980) and, as a
consequence, the first half of the 20th century saw large expanses of former wetlands
transformed onto salt ponds, industrial land, large infrastructure and, eventually, even
residential areas.
2.4.2 Environmental protection standards and the concept of “high water line”
Around the Tagus, Roman doctrine regarding the protection of public waters has been
enforced, with varying degrees of effectiveness, since the first half of the first
millennium. It was upheld through a sequence of legal disputes, in the first centuries
of Portuguese nationality (12th-15th century) and was clarified during the reign of King
John I, with the 1410 Crown Court’s ruling that reasserted the Crown’s right to all
lands subject to regular flooding by the “December High Waters”. This standard would
translate to today’s Portuguese standard, which is the “Highest Astronomical Tide
Line” (HAT) (Rilo 2014). This corresponds to the exceptional elevation of waters
during the Equinoctial Spring Tides, that is, the largest tides of the year.
In contrast, the same Roman legal code was transferred onto English Common Law
and later into US law, with several important distinctions. The most relevant of which
would be the interpretation of the “High Water Line”, which delimits the Public Trust.
Already present in British legal standards (with the exception of Scotland, which
upholds the higher Mean High Water Spring standard), the High Water is considered
in most US states, including California, to correspond to the Mean High Water (MHW)
in coastal regions. MHW corresponds to an averaging over a 18.6-year lunar cycle of
all the high tides of each day. The subtle distinction between adopting an “average”
high tide or an “exceptional” high tide has important implications over the level of
protection granted to coastal wetlands and the ability to prevent development in very
low-lying land. As an example, the Mean High Water in Lisbon is ~0.86 m below the
Highest Astronomical Tide (HAT) standard (Antunes 2011). Such a difference in
elevation can extend dozens of meters across flat shorelines, and represent the
difference between including all beaches, wetlands, and adjacent shorelines or
excluding a significant portion of these. Additionally, the Californian Public Trust was
complemented, specifically in the SF Bay, by a very limited planning mandate
(addressing mostly provisions for public access) over a buffer strip 100ft (~30m)
wide granted to the BCDC. Therefore, any development proposed immediately above
the MHW may theoretically receive the go-ahead from city planning commissions. In
contrast, the already generous Portuguese definition of the high water line is further
reinforced with a full public planning mandate over a 50 m buffer inland from the
HAT. Together they form the core of the Portuguese Public Domain, which is
complemented by a limited planning mandate for an adjacent zone extending another
500m inland. In practice, outside existing urban perimeters, no further development
46
is likely to receive approval according to the new Tagus Estuary Management Plan
(APA 2013).
Both legal codes include provisions regarding erosion and avulsion (again, derived
from very old doctrines, which may be traced back to at least the Justinian Code). The
Portuguese Water Law of 2005 (Assembleia da República 2005) specifically mentions
that all land lost to natural processes of erosion or flooding, including those
potentiated by rising sea levels, is to be automatically considered to integrate the
“bed” of rivers and sea shorelines, and the Public Domain provisions accordingly
realigned. In the US, similar provisions deriving from the Common Law presuppose
the inclusion in the Public Trust of land lost to erosion (Eichenberg 2013). In both
estuaries, the end of landfilling, the steady creation of natural reserves, parks and
refuges, as well as the recent introduction of more environmentally-friendly dredging
practices (LMTS 2001, BCDC 2011, APA 2013) have contributed greatly towards the
protection of existing wetlands and permanently submerged habitats.
The water quality in the Bay has been steadily improving since the application of state
(1969) and federal (1972) laws regarding waste water treatment (Okamoto 2011:
158-160). The Tagus Estuary followed suit, albeit with a couple of decades’ delay:
waste water treatment was mandated across the whole Tagus river basin as Portugal
and Spain complied with the European Urban Waste-Water Directive (91/271/CEE
Directive) of 1991 and subsequent provisions. At the estuarine level, the conclusion of
the related integrated waste water management system, accompanied by the
relocation of heavy industries, led to water quality improvements over the last two
decades.
Despite the long sequence of anthropic impacts, both estuaries remain very important
natural habitats, and both are recognized as Ramsar sites of international importance
along major flyways (McLusky 2004, Costa 1999). With water quality becoming less of
a problem, the medium- to long-term strategies of dam removal, or at least the
integration onto existing dams of functional fish passages (Cech 2010:428-435) and
other measures, may in time allow the return or stabilization of anadromous fish
stocks, and allow for a more sustainable sediment management (Kondolf 2000, 2014).
This later aspect would likely be of crucial importance in enhancing wetland resilience
in face of the increased rates of SLR, expected towards the end of the century, as the
sustainability of wetlands appears to be strongly connected with the maintenance of a
good sediment supply (Orr 2003, Watson 2013, Stralberg 2011, Swanson 2014,
Duarte 2013, Silva 2008, Silva 2013).
2.5 Conclusion
Both estuaries share similar physical settings, have been affected by synchronous
fluctuations in eustatic sea levels, and are located in mediterranean climate zones. The
Tagus estuary has experienced continuous human settlement and progressive
transformation of natural systems throughout over 2 millennia. The process of
transformation of wetlands onto farmland was gradual, albeit characterized by
periods of accelerated reclamation. The legal framework and actual reclamation
practice can be traced back to the Roman tradition,m and have been applied to the
47
slowly-evolving landscape ever since. The pushes for transformation can be related to
the Crown/State’s desire to expand profitable farmland, but provisions to ensure that
it remained within the Public Trust prevented the full appropriation of land by private
landowners and, consequently, contributed to limit the more recent transformation of
lowlands onto residential or industrial uses. In contrast, the San Francisco Bay’s
estuarine ecosystem went largely undisturbed until the second half of the 19th
century. Since then, it experienced the impacts of human activity at an extremely
accelerated rate, with the input of sediment from the Central Valley increasing by a
full order of magnitude and back within little more than a century. Direct shoreline
alteration was equally extensive and, unlike in the Tagus Estuary, the Public Trust
over the bed was not fully upheld until the 1960s. Thus, besides transformation into
farmland, landfills around the Bay are now abundantly built-over, with uses ranging
from salt ponds, industrial zones, and even residential neighborhoods.
While both legal frameworks share a common ancestry which may be traced back to
the Roman Law, we have established that they were upheld more rigorously, or at
least consistently, in the Tagus Estuary and, as a result, most lowlands around the
Estuary remained under public control and free from permanent building. Although
most wetlands have been reclaimed, farmland occupies almost all drained areas.
Around the SF Bay, estuarine beds and wetlands were, during a period of accelerated
urban expansion, sold to private developers and were converted to a much greater
extent to industrial, infrastructure, and urban uses. This is in contradiction to the
original provisions of the Public Trust Doctrine, and could be characterized as a
relaxation of its enforcement during a period when environmental standards were not
a priority as compared to the urge to encourage settlement and grow the regional
economy.
The standard for the delimitation of the upper limit of the Public Trust/Public Domain
is more generous in Portugal than in California. Portugal has, through historic
tradition, adopted the Highest Astronomical Tide as a reference, against the Mean
High Water standard for California. Portuguese laws also grant the public agencies
with a full planning mandate over a 50m strip inland from the HAT line, and an
additional 500m buffer with limited planning mandate. In contrast, the BCDC only has
a limited planning mandate over a 30m buffer, mostly related to the assurance of
public access in new development.
Wetlands around the Tagus Estuary could more easily be allowed to migrate upland
as the more sensitive habitat is adjacent to farmland, whereas around the SF Bay most
wetlands are severely encroached upon by urban infrastructure. Also, a steady
improvement in the Portuguese legal framework, including the expansion of
environmental planning mandates of public agencies, now lends the estuary a strong
level of protection. On the other hand, SF Bay has experimented with over four
decades of wetland restoration and tidal reconnection of formerly diked ponds, and
the metropolitan area is now a global leader in green adaptation, with a greater level
of involvement of private sector and civil society in climate adaptation efforts.
48
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3 A TALE OF TWO ESTUARIES: GOVERNANCE, ENVIRONMENTAL
PLANNING, AND ADAPTATION TO SEA-LEVEL RISE IN SAN
FRANCISCO AND LISBON
A version of this chapter has been submited for review to
Land Use Policy (ISSN:0264-8377)
3.1 Introduction
Estuaries are among the most ecologically productive and biodiverse natural
environments, hosting wetlands crucial as stops along bird flyways and as nurseries
for fish (McLusky 2004, Costa 1999). Estuaries are often good natural harbors, and
several of the world’s largest port cities developed on estuaries to benefit from both
the location at the crossroads between inland and sea trade and the adjacent fertile
alluvial floodplains. These cities have encroached upon the estuarine shores
degrading the quality of the natural environment, commonly displacing wetland
habitat for urban areas and infrastructure (Goals Project 1999, Caçador 2001).
Despite recent efforts to protect and restore estuarine ecosystems, both urbanized
and still-natural estuarine shorelines are now vulnerable to accelerated sea-level rise
by virtue of their extensive areas at or just above mean sea-level (Wong 2014, Ericson
2006, Church 2008, Hanak 2012, Andrade 2002).
In these settings, the cost of inaction in face of rising seas is simply too high (Heberger
2009, EEA 2013, ANPC 2010), motivating some estuarine cities to begin to adapt to
sea-level rise. This will require modifications to the urban and environmental
planning structure. San Francisco Bay, California, USA, and the Tagus Estuary in the
Lisbon Metropolitan Area, Portugal, both large urbanized estuaries, make excellent
case studies by virtue of their remarkable geographic similarities but distinct
traditions of environmental planning and governance structure.
San Francisco Bay (henceforth, SF Bay), is the estuary of the Sacramento River, and
the largest estuary along the west coast of North America. The Tagus Estuary
(hereafter, the Tagus Estuary) is the estuary of the Tagus River, and the largest
estuary on the Atlantic coast of Europe(Figure 9). The two estuaries are similar in
many important respects, but also have notable differences (Table 4). Although SF Bay
is significantly larger than the Tagus Estuary in surface area (~1260 km2 vs ~320
km2, EPA 2011, Gameiro 2007), both constitute key wetland ecosystems for major
flyways and serve as nurseries for important offshore fisheries (Okamoto 2011, Catry
2011, Costa 1999). Today, both SF Bay and the Tagus Estuary are surrounded by large
metropolitan areas: the San Francisco Bay Area is home to about 7 million (the second
largest metropolitan area on the Pacific coast of North America), and the Lisbon
Metropolitan Area has about 3 million and is the largest urban center located directly
on the Atlantic Coast of Europe. Geomorphically, both estuaries are “drowned valleys”
(McLusky 2004), shaped by alternating episodes of active incision during ice ages and
marine transgression during warm periods (Atwater 1977, Vis 2008). These marine
and fluvial processes, coupled with active tectonic uplift and subsidence, have created
“bottlenecks” at the mouths of both estuaries, partially protecting their wide inner
basins and inland deltas.
58
The Tagus River is dammed by 10 dams on the main river and 80 dams on tributaries
(35 in Portugal and 45 in Spain), reflecting the fact that the river passes through many
bedrock outcrops that afford good dam sites. The Sacramento River and San Joaquin
have fewer dams on the alluvial Central Valley, but virtually all of its tributaries are
dammed. Despite this, the Sacramento River system still supports runs of anadromous
pacific salmon, which are priority species for conservation efforts. While the Tagus
River still hosts several endangered species, communities of anadromous fish have
been severely impacted by damming, diversion, overfishing and pollution. Both
estuaries experience Mediterranean type climates, with high seasonal and interannual
variability in rainfall and thus fresh water inputs into the estuaries. Both estuaries
have been subject to deep anthropogenic impacts on their wetland ecosystems and
are now under a common threat from sea level rise.
Figure 9 – Maps of the San Francisco (a) and Tagus (b) estuaries shown at the same
scale, showing locations referred to in the text.
While physically and ecologically similar, these two estuaries have distinct histories of
human occupation and have developed different legal and institutional approaches to
land management (Chapter 2), which are reflected both in the nature of the threat
now posed by accelerated sea level rise and in the institutional and legal structures in
place to protect the remaining wetlands and to respond to sea level rise. Recurrent
episodes of flooding in low-lying landfills during storm surges (for instance in
Embarcadero, San Francisco, and in Alcântara, Lisbon) reveal that SLR is already
producing negative impacts in both estuaries. These extreme events are often triggers
59
for increasing awareness of climate change and its effects (Tollefson 2012), which in
turn may lead to expedited incorporation of adaptation onto public policy and legal
frameworks (EEA 2012a, IPCC 2012, Birkmann 2010, Carey 2011). Our research
compared the governance structure and regulatory/planning frameworks in these
two estuaries through review of relevant documents, semi-structured interviews with
key players in planning and adaptation to sea-level rise, and examples of concrete
instances of sea-level rise adaptation solutions, strategies, and standards being
implemented in both regions. Based on this research, we identified opportunities to
improve governance frameworks and planning processes.
Table 4 – Characteristics of the San Francisco and Tagus estuaries.
These two case-study estuaries can be considered as ‘early adopters’ of adaptive
planning frameworks and solutions within their respective traditions of planning and
governance structure (i.e., US and Europe, Svensson 2008) and thus lessons learned
from these systems and their comparison may be helpful in the greater context of
adaptation across both continents.
60
3.2 Materials and methods
3.2.1 Reconstruction of Environmental Histories and vulnerability to sea-level
rise
For San Francisco Bay, we used as reference prior reconstructions of past geography
and bathymetry (Schoellhamer 2013, Kirwan 2011, Goals Project 1999, Watson 2013,
Atwater 1977, Wright 2004, Okamoto 2011). To reconstruct the evolution of the
Tagus estuary, we drew upon prior studies of historical change and paleostratigraphy
(Vis 2008, Martins 2010, Dias 1997, Uribelarrea 2003), and primary sources, for
historical documentation of land-use (Beirante 1998, Madaleno 2006, Soares 2011)
and for the characterization and modern distribution of wetlands (Vale 1987, Gameiro
2007, Ribeiro 2003, Martins 2010).
To compare the vulnerability of estuarine shoreline lands to sea level rise, we
superimposed projected future sea levels on digital terrain models (DTMs) of the two
estuaries. We very coarsely simulated the effects of different thresholds of SLR over
the low-lying areas of both estuaries, while simplifying maps to portray only three
main land-cover categories: urban areas, rural areas, and wetlands. In this simple
analysis, we determined extent of inundation from future static sea level rise (i.e., not
accounting for wave run-up or local hydraulic effects) by superimposing elevated sea
levels over current land use and wetland distribution (Table 5). For each elevation, we
determined the potential exposure to future flooding of each major land use.
Layers
Altimetry
San Francisco
Bay Area
Lisbon Metropolitan
Area
Data processing
National Elevation Dataset - Shuttle Radar Topographic Creation of mask layers for current MSL,
USGS
Mission - NASA
+1m, +2m, +3m, +5m and +10m
Land Use
National Land Cover
Database 2006 - USGS
Wetland maps
EcoAtlas Modern Baylands SFEI
Reclassification of land use into three
Carta de Ocupação de Solo
classes: built-up areas, non-built-up areas,
2007 - IGP
permanently flooded areas
Georreferrenced from
Ribeiro 2003, Gameiro
2007
Reclassification of wetlands into three
categories: mudflat, saltmarsh, and
regulated/salt ponds
Table 5 – Data sources used in the flood mapping of both estuaries.
Similar analyses have been previously undertaken specifically for the SF Bay and
California (BCDC 2011a, Heberger 2009, OCOF 2013), or more broadly, for all US
coastal areas (NOAA 2011, Climate Central 2014). For the Tagus Estuary, the main
SLR modelling effort has been carried out by Project Morpheed (Freire 2013) of the
Portuguese National Laboratory of Civil Engineering (LNEC). These simulations were
used as a reference for the Tagus Estuary Management Plan (APA 2013). Other
simulations have focused especially on local impacts over urbanized waterfronts, such
as the project “Estuários e Deltas Urbanizados” (Costa 2013) and “CHANGE Mudanças Climáticas, Costeiras e Sociais” (Schmidt 2013).
However, to ensure the consistency in same methods and assumptions in the
comparative analyses of both estuaries (i.e., to avoid apparent differences that might
61
be artifacts of the methods rather than real differences between the two cases), we
independently conducted these analyses. Thus, our results might differ in some details
from prior studies, but our emphasis was on understanding large-scale trends and
differences between the two estuaries, and thus replicating the analysis in a consistent
manner for both estuaries was necessary.
The resulting flood maps and tables are presented in Appendices A, B, and C.
3.2.2 Documentation and Analysis of Key Players and Plan Development
We conducted an in-depth analysis of the planning processes leading to the
publication of the Climate Change Bay Plan Amendment (BCDC 2011b) and nearpublication of the Tagus Estuary Management Plan (APA 2013).
We conducted semi-structured interviews with 12 policy makers, experts and
stakeholders in both cities. Neuman (1991) describes different types of interview.
Structured interviews typically aim at obtaining ‘processable’ data. As such, typified
answers, that could be easily coded and compared as ‘data’ are preferred to openended entries. Given the type of information required in the study of urbanized
estuaries, semi-structured interviews are more suited. The objective of the interviews
is to obtain as much relevant information as possible from an expert or to accurately
portrait the position and opinions of a stakeholder with regards to a given problem.
Similar methods have been employed in several environmental governance and
climate change-related studies, including Swanson (1975), O’Toole (2013) and
Schmidt (2013).
We guided each interview around a loose script with 5 pre-set topics:
1 – How do you/your institution perceive sea-level rise: as a threat, an
opportunity, or both?
2 – What is you institution’s main role and stake regarding SLR: Environmental
protection; Defense of its jurisdiction; Protection of investments/
infrastructure; Other – which?
3 – Which would be the main drivers/goals of present or future adaptation
strategies?
4 – How do you foresee SLR affecting the role and/or procedures of your
institution within the next 10, 25 or 50 years?
5 – Did your institution revise its standards & practices to accommodate
adaptation to SLR? Could you specify a few relevant measures?
Interviews lasted about 2 hours, and interviewees were allowed to pursue other
topics related to regional planning and SLR adaptation. We conducted 12 interviews
(6 in each city) with a total of 16 participating stakeholders and experts.
Based on the review of planning documents from 1965 to present and our interviews
with policy makers and stakeholders, we identified all the agencies involved in
62
decision making and/or plan implementation in both estuaries. We also identified the
number of ecological reserves and open spaces in each estuary system, as an
indication of complexity in management of estuarine lands and water. For a recent
wetlands restoration initiative in each estuary (the South Bay Salt Ponds Restoration
Project in SF Bay, and the Samouco Salt Ponds Restoration Project in the Tagus
Estuary), we identified key players and their roles.
3.3 Results
3.3.1 Environmental histories and resulting land-use patterns of the estuaries
San Francisco Bay
What is now San Francisco Bay was a broad alluvial valley during low stands of sea
level during the glacial advances of the Pleistocene. After the last ice age, sea level rose
sharply 60m between 11,650–7000 Y.B.P., flooding the SF Bay (Smith 2011, Atwater
1977). Since then, the SF Bay has been filling with sediments from its tributary rivers
and through expansion of tidal wetlands. Wetland expansion accelerated during the
Little Ice Age (ca. 1550 to ca. 1850), such that the 19th-century extent of tidal wetlands
(commonly used as a reference for tidal wetland restoration) may have been
unusually large (Watson 2013).
The SF Bay Area remained a largely undisturbed natural environment up until the
mid-1800s, but the influx of European settlers during the gold rush caused massive
alterations over a short timeframe. Alterations to the land cover of the river basin and,
especially, the use of hydraulic mining technology in the gold fields in the second half
of the 19th century produced a 10-fold increase to the input of sediment to the SF Bay.
However, by the mid-20th century, sediment delivery had declined sharply as a result
of sediment trapping by dams (Orr 2003, Wright 2004), and has likely fallen below
pre-disturbance levels, as the remnant sediment from the hydraulic mining era leaves
the system and remobilization of additional sediment from the interior valleys
becomes less likely under the current management of reservoir capacity. The lack of
sediment supply in reaches downstream of dams (“sediment starvation”, Kondolf
1997) now poses a limitation on efforts to rebuild tidal wetlands in SF Bay (Barnard
2013, Schoellhamer 2013, Wright 2004, Watson 2013).
Until 1965, the SF Bay shorelines did not enjoy legal protection, and they were
extensively altered by dyking and landfilling, activities encouraged by national and
state law. At the federal level, the Arkansas Act (1850) made appropriations of
“swamp and overflowed” lands a prerogative of the states, and California passed
legislation promoting the dredging and filling of wetlands for agriculture (Luken 1974,
Swanson 1975). Various estimates of loss of the original wetlands to landfilling and
dyking indicate that over 90 percent of the mid-19th-century extent of tidal wetlands
was lost by the late 20th century (Goals Project 1999, Williams 2001, Madsen 2007).
The tipping point that put a halt to the reclamation frenzy came after two infamous
projects, the Reber Plan of the 1940s (Price 2002) and the United States Army Corps
of Engineers (USACE) study that followed (Swanson 1975, BCDC 1998:4). This was a
63
proposal to landfill most shallow areas of SF Bay and to create two large earthen dams
to transform San Pablo, Suisun and South SF Bay into fresh water reservoirs. These
proposals were met with public outrage and were eventually dismissed by USACE as
inviable due to their environmental impacts (Saunders 2009). However, the struggle
to protect SF Bay against extensive fill had a deep impact on public perception of the
SF Bay, and motivated the emergence of environmental NGOs, passage of legislation
establishing public agencies, and public-private partnerships dealing specifically with
environmental issues related to the SF Bay (Walker 2009). In particular, the NGO Save
the Bay successfully lobbied for the MacAteer-Petris Act (described below), which
halted fill of the open Bay waters and within a 30-m coastal strip in 1965.
The SF Bay was polluted by discharge of untreated industrial and municipal sewage
until the closure of many bayside industries and extensive construction of wastewater
treatment plants following passage of the Clean Water Act (Okamoto 2011).
Nonetheless, by 1965, extensive areas of tidal and sub-tidal lands had been dyked off
and/or filled, and converted to residential and industrial uses. Much of the land
originally “reclaimed” for agriculture, and part of that dyked-off as salt ponds, was
later converted to infrastructure, industrial, and urban uses. Salt ponds at one time
occupied as much as 36,000 ha (Goals Project 1999), part of which have since been
converted to other uses or restored to managed wetlands, and we estimate that close
to 20,000 ha of former Baylands (~8.6% of the maximum historical extent of the SF
Bay) have been permanently converted to urban areas and infrastructure (Chapter 2).
Areas more than 30 meters from the 1965 shoreline and already zoned for
commercial, industrial, or residential uses could still be built upon. The result was
extensive development of buildings and infrastructure within a few meters above
mean sea level along the margins of SF Bay.
The Tagus Estuary
The Tagus Estuary was similarly created after the end of the last glacial period by
flooding during the sharp increase in global sea-level (Dias 1997, Vis 2008). Although
accurate descriptions of the estuary are lacking before formation of the Kingdom of
Portugal (mid-12th century), some documents hint that there was already a practice of
draining the lezírias (tidal flats) for farmlands before then (Beirante 1998). The
modification of the watershed (Uribelarrea 2003) and virtual extirpation of primeval
forests was completed before the end of the middle ages (Pinto 2012), resulting in
greater influx of sediments onto the estuary, which likely accelerated the rate of
wetland expansion and extent of potential lezírias farmland. Since the mid-20th
century, dams on the mainstem Tagus and its tributaries (in both Spain and Portugal)
have extirpated anadromous fish runs and reduced the sediment yields dramatically
(Andrade 2002: 187).
Attempts to defend the highly productive agricultural lands on Tagus delta (the upper
part of the estuary) against floods and high tides required constant maintenance of
protective walls. Several campaigns to encourage further creation of these farmlands
are documented in the historical record (Madaleno 2006, Beirante 1998, Martins
2010). These suggest that either these farmlands were cyclically abandoned and the
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crown had to promote their reconstruction, and/or that the expansion of the lezírias
farmlands advanced with the natural process of delta progradation. This historical
practice is consistent with the practice of reserving all land below “the December High
Waters” for the Crown (that is, in Public Domain), a measure grounded on the old
Roman tradition of a public trust protecting all navigable waters and floodplains
(Beirante 1998). In 1864, all shores subject to inundation at the Highest Astronomical
Tide (HAT), plus a 50-m wide strip inland, were designated Public Domain by the
Royal Decree of December 31st. Some 30 years before, the Companhia das Lezírias,
then a private society, was created to manage the farmlands belonging to the Crown
Prince. The model of public-led management of the bulk of farmland located on the
alluvial plain persists to this day, and has largely prevented urbanisation of these
productive agricultural lands. The last major effort to reclaim tidal lands (probably a
combination of salt flats and relic high marsh) for agriculture was the 1910 campaign
to drain 4,000 ha in the Lezíria Grande (Madaleno 2006). In the mid 20th century some
areas in the south bank of the estuary were landfilled for the expansion of large
industrial units and to expand the waterfront available for shipping, but these areas
combined were restricted to less than 700 ha (Chapter 2) or less than 1% of the
maximum extent of estuarine lands. A plan that proposed the reclamation of a further
8,000 ha of shallow estuarine areas, including mudflats and most of the remaining
patches of salt marsh, was considered in the 1950s, but the project was postponed
and definitively abandoned for environmental reasons in the 1970s (Costa 1999: 41).
The estuary’s water quality was compromised by untreated industrial and sewage
effluent, with severe impacts on the estuarine ecosystem (Costa 1999, Caçador 2001).
Tightened water quality standards, closing down of major industries, and major
investments in primary and secondary water treatment along the Tagus river basin at
the turn of the 21st century (Costa 1999: 164, Soares 2011) resulted in steady
improvements in the water quality in recent decades.
Since the late 1980s, the original Public Domain has been reinforced with a limited
planning mandate over a transitional zone, a buffer extending 500 m inland from the
HAT + 50 m. This, in addition to legislation protecting specifically wetlands, the best
soils, the best habitat and sensitive areas, means both wetlands and upland farmland
and forest patches around the estuary are well protected from transformation.
Furthermore, the national law establishes that “land lost to the sea” through erosion is
to be automatically incorporated into the Public Domain, and the adjoining buffers
realigned according to the new shoreline. If this jurisprudence is upheld, it establishes
a very strong public trust doctrine regarding rising seas. Equally, public
environmental protection and port agencies have been granted very strong mandates,
which have steadily been expanded through the passing of new legislation, often
championed by the European Commission and reflecting advancing paradigms in
environmental protection and resource management.
The result is that, while there are extensive urban waterfronts around the Tagus
Estuary, the vast majority of low-lying areas along the estuary shoreline are, to this
day, occupied almost exclusively by wetlands and agricultural land (in strong contrast
to SF Bay).
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3.3.2 The Planning Instruments and Planning Processes
San Francisco Bay
The institutional framework of San Francisco Bay is exceptionally complex, with over
100 local governments and multiple layers of state, regional, and federal authorities
(Figure 10). This reflects a Californian preference for the multiplication of public
agencies pursuing very specific and narrow mandates (Fulton 2012: 76, 89-104). The
planning process is also characterized by a great level of involvement in the decisionmaking process of a multitude of NGOs, private interest groups, or even individual
citizens (Fulton 2012: 108-109).
Figure 10 – Complexity of the planning systems.
The main entity responsible for the coordination of environmental protection in the
SF Bay Region is the San Francisco Bay Conservation and Development Commission
(BCDC), created by the McAteer-Petris Act, passed by the California Legislature in
1965. The Act specifically addressed the relentless landfilling around the SF Bay and
66
reflected the increasing awareness and concern over the extirpation of its wetland
ecosystems, raised by the emergence of a second-wave of local environmental
activism, championed by the NGO Save The Bay (Walker 2009). At the time of its
creation, the BCDC was the first coastal commission established in the United States. It
predates several landmark state and federal legal documents addressing
environmental protection, such as the State’s Porter-Cologne Water Quality Control
Act of 1969 and the Federal Coastal Zone Management Act and the Clean Water Act,
both from 1972. It equally influenced the establishment of the State-wide California
Coastal Commission (1972) and several other similar agencies across the country.
As a trailblazer, BCDC’s original mandate was somewhat narrow (Davoren 1982), and
its authorities were overlain on top of the authorities of pre-existing agencies, within a
very complex governance structure composed of three levels of government: federal,
state, and local. The California Water Resources Control Board (CWRCB) and the SF
Regional Water Quality Control Board (SFRWQCB) are both derived from a State
agency dating back to 1949 tasked with the difficult balancing of water allocations
across the state, and since 1972, with enforcing aspects of the federal Clean Water Act.
Through basin-wide as well as local actions, these regional boards have been
successful in vastly improving the water quality of the SF Bay.
The US Army Corps of Engineers remains largely responsible for the management of
dredging, now mostly associated with the maintenance of navigation channels on the
SF Bay (LMTS 2001). Both the US Environmental Protection Agency (EPA, created in
1970) and the Corps are tasked with issuing and enforcing permits for dredging and
filling, including on wetlands and salt ponds under the Clean Water Act. The BCDC’s
mission has been complemented by the California Coastal Conservancy (1976),
dedicated more specifically to the protection and restoration of coastal and wetland
habitat.
Several other agencies and a myriad of city governments and special districts (local
entities typically created to pursue a single function, such as water treatment,
education or flood control) also have stakes on shoreline development, coastal
defense infrastructure, and environmental protection. Given the complexity of this
institutional framework, it is no wonder that, ever since its creation, the BCDC had to
set up collaborative mechanisms to engage local, state, and federal agencies in
establishing planning and protection strategies and coordinating actions and
standards (Davoren 1982, Eichenberg 2013).
The Bay Plan Climate Change Amendment
The main document organizing environmental protection of SF Bay is known as the
“Bay Plan”. First published in 1968 by the BCDC, it established the “blueprint” for the
protection of the SF Bay (Schoop 1971). The Plan has been amended several times
since its creation. Our focus is mainly on the most recent Climate Change Amendment
(BCDC 2011b), intended to reflect current knowledge of sea level rise and its
implications for SF Bay.
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From the onset, the McAteer-Petris Act sought to put a halt to the landfilling of the SF
Bay. The Plan therefore strictly regulates all filling within 100ft inland (~30m) from
the Mean High Tide line. It established a zero-net-loss policy on Baylands, which
promotes the offset of all landfill and dredging through onsite remediation or off-site
compensation of the lost tidal lands. This practice has been responsible for a few of
the early wetland restoration efforts, which have expanded to become one of the
staples of Bay Area environmental protection (interviews 5, 8, 10 & 11). The Plan also
addresses and articulates interventions requiring landfilling or dredging, such as the
deepening of navigation channels or the expansion and maintenance of port and
airport infrastructure.
Nevertheless, the Amendment was limited in its scope by the equally narrow planning
mandate within which the BCDC has to operate: decisive action in preventing new
development just above the current public trust is severely restricted, and mostly
limited to the enforcement of “maximum feasible public access” and the
recommendation to discourage low-land development. All further proposals that
could legally deter it, though, were met with strong resistance by the business
community and some local governments, and even BCDC’s flood maps for 16” and 55”
of SLR, designed as a tool to raise awareness to the foreseeable consequences of
climate change, had to be annexed to the Plan as a non-binding element with no legal
standing (Eichenberg 2013). Its shortcomings, especially when it comes to the
inclusion of binding measures related to shoreline land use, is equally revealing of
some issues influencing the environmental planning of the SF Bay, as we shall discuss
further ahead.
The Tagus Estuary
The Tagus Estuary’s governance structure is comparatively much simpler, with fewer
public agencies involved and more limited input from stakeholders (Figure 10).
Environmental planning initiatives and revisions to regulation are characterized by
relatively simple direct negotiations between public agencies, a top-down decisionmaking structure, and strong (and frequently expanded) mandates supported by the
legislature. Expanded environmental protection standards for water quality, land-use
planning, and environmental protection have typically been reflected in expanded
mandates and jurisdictions of already-existing national agencies.
The institutional framework is also much simplified because the roles of different
levels of government are more clearly defined. The equivalent of the US Federal level
would be the European Parliament, Commision, and executive agencies such as the
European Environment Agency (EEA), but EU directives and standards must first be
transposed into national legislation before influencing national and local government
actions (Pettersson 2013).
Because Portugal lacks regional governments (Thiel 2015), this effectively means all
nation-wide and regional coordination is nested under national agencies. These large
agencies and institutes, such as the Portuguese Environment Agency (APA), are
typically organized through a branching structure of departments and regional offices,
similar to that of US federal agencies. Local governments are limited to one form, that
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of the municipalities (which typically include both urban centers and surrounding
rural areas) and there is no concept of incorporated city vs. county as in the US. In
terms of their attributions, Portuguese municipalities are comparable to US situations
where city and county boundaries coincide (such as the City and County of San
Francisco). They have a strong planning autonomy for land-use choices, especially
regarding urban planning, but are required to reflect all public easements and
environmental standards, emanating from upper-level plans and revised laws, in their
municipal land-use plans.
The APA oversees environmental planning efforts, and has to coordinate with the
Tagus Estuary Nature Reserve, a national-level park, which grants special protection
and enhanced monitoring of environmental performance and human activities over
the most sensitive wetland and adjacent areas. Established in 1976, the Reserve is
managed by the Institute for Nature Conservation and Biodiversity. The Port
Authority, established as autonomous public administration in 1907, has a jurisdiction
over most shorelines around the Estuary, but upholds it only over “active” port areas,
mostly concentrated in urban waterfronts in the municipalities of Lisbon, Almada,
Barreiro and Vila Franca de Xira. It answers directly to the Ministry of Economy, and
coordinates most dredging operations in the Estuary, in coordination with the APA.
Since 2009, some stretches of urban riverfront with no port use have been transferred
from the jurisdiction of the Port Authority to the municipalities.
The Tagus Estuary Management Plan
The estuary’s major environmental protection instrument will be the new Estuary
Management Plan (Estuary Plan, APA 2013). It is instructive to go briefly through the
process by which the Estuary Plan was developed. The European Union Water
Framework Directive (WFD, Directive 2000/60/EC, adopted in 2000) requires riverbasin level planning and management of water. In Portugal, and after the
transposition of the WFD onto the National Water Law (Law 58/2005), five
Hydrographic Region Administrations (in Portuguese, Administrações de Região
Hidrográfica, or ARH), branching out of the Portuguese Water Institute, were
established as the ‘competent authorities’ to carry out the actions required by the
WFD. These included the creation of River Basin Plans, Coastal Management Plans,
Reservoir Management Plans, and Estuary Management Plans.
However, in 2012, the ARHs were eliminated as part of austerity measures, and the
mandates and capabilities of the ARHs were collapsed into an autonomous unit within
the APA. For the Tagus Estuary, environmental planning efforts are currently led by
the APA. Besides inheriting all the capabilities and mandates of the Tagus ARH, the
APA also includes departments tasked with national and regional climate adaptation
strategies, the coordination and funding of environmental mitigation, coastal defense
infrastructure, water quality, and flood management, and is responsible for
environmental licensing of water uses, dredging and filling operations. It oversees the
protection of the Public Domain and all wetlands.
The Estuary Plan will be one of the last elements required by the Portuguese
legislation transposed from the WFD to materialize. In pursuance of the National
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Water Law (Law 58/2005), the Decree-of-Law 129/2008 sets the specific legal
framework for the Estuarine Management Plans. This planning instrument will
coordinate the activities of public agencies and private landowners and activities. It
also articulates the existing protection mechanisms and expands wetland monitoring
(already routinely conducted by the Nature Reserve) to other patches of salt marsh,
beaches and mudflat, notably along south-bank embayments. It establishes priority
interventions in the remediation of several natural or semi-natural shorelines.
Having been elaborated in close coordination with the Nature Reserve and the Port
Authority, the Plan also received inputs from the Nature Reserve’s own management
plan (which led to the inclusion of that instrument’s best practices and knowledge on
wetland protection and monitoring) and informed the revision of the Port Authority’s
Dredging Plan, which allowed best environmental practices to be defined with regard
to timing, extent, and location of dredging and deposition of dredged material in the
estuary. It included the provision to deposit clean dredge material in upstream
locations, from whence it can be recirculated through the estuary as suspended
sediment, to support wetland accretion through sediment fixation.
Under the then-autonomous Tagus ARH, more direct and fruitful cooperation
occurred between institutions during the plan’s elaboration, as was acknowledged by
Interviewees 1, 3 and 12, but public participation in the decision-making process
remained limited, especially when compared to the levels of stakeholder involvement
in SF Bay. Nevertheless, the ARH established good communication channels with
other public agencies and held public meetings to inform and engage local populations
and stakeholders.
Further involvement may require a longer tradition of collaboration in planning,
although the Plan marks somewhat of a departure from the typical Portuguese coastal
planning process, as described by Schmidt (2013), especially in that there was
improved communication among major stakeholders, a clarification of each agency’s
role, and a greater involvement of the scientific community (Interviews 1 and 12).
Nevertheless, participation in the definition of regional strategies and most
regulations included in the Estuary Plan was concentrated among a few large public
agencies (mostly the ARH and the Port of Lisbon, with additional inputs from the
Natural Reserve and consultation of experts and municipalities) and reflected simple
negotiations through direct channels of communication.
Engagement of the general public and other stakeholders was mostly restricted to
formal mechanisms such as notices or invitations for public consultation of plans,
which may be attributed to a two-way distrust: the general public is often perceived
by planning agents as being unable to contribute constructively to the process beyond
the assurance of personal stakes, and the latter are viewed as unable or unwilling to
engage in truly participatory processes, and participation is sometimes discredited as
an inconsequential process (Schmidt 2014). The ARH nevertheless attempted to
create more frequent platforms for public engagement, including local forums where
inputs from residents and local interest groups were received.
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As the need for environmental protection becomes an uncontroversial staple,
grounded on established legal standards, these agencies’ positions on environmental
planning often coincide (or, at least, do not clash), and more open collaboration
among them has improved articulation of policies and interventions (Interviews 3, 4,
12).
However, the relative lack of public involvement in plan formulation and decisionmaking means that top-down decisions reached through compromise among national
agencies can trigger strong controversy when presented to the public and local
governments as fait accompli. These are often smaller decisions imposed onto a
greater planning framework, but yet, through the controversy they generate, may
impair the approval of the otherwise well-received broader document.
This occurred with the Estuary Plan when its preliminary version was released to
stakeholders in 2012: In addition to the consensual coordination of environmental
planning across the Estuary, the Plan included a land reserve for the future
construction of the new container port terminal, then proposed for Trafaria. The
inclusion of such a large infrastructure project in the plan, without prior public
consultation over potential environmental, economic, and social impacts, was met
with intense resistance by environmental NGOs and citizen groups.
The situation has been further complicated by institutional changes, as the five ARH
have been merged into an expanded Portuguese Environmental Agency. Although
most of the former agencies’ structures remained intact, the simple integration within
a much larger and complex hierarchy has impaired their ability to successfully
conclude their planning efforts, by: (1) leading to a much limited ability to
independently establish direct communication channels with other agencies and local
actors (as mentioned in Interview 12); and, (2) creating a less direct communication
route to the upper levels of central government and legislators, which now has to be
navigated along competing demands from several other regional plans and interests.
Likely as a consequence of this less streamlined decision-making structure and the
controversy related to the new container terminal, the Estuary Plan has been in
“limbo” for over two years. The Plan awaits only a final conciliation stage and
ratification, but this has proved elusive because of the resistance to the new container
port terminal, which was effectively “slipped into” the Plan without public
consultation or buy-in.
3.3.3 Comparing Conservation and Sea-Level-Rise Adaptation Efforts
Conservation efforts
The management of the shorelines of SF Bay is a complex business. Besides the
extensive sections of shoreline that have been landfilled and modified into
infrastructure such as ports, airports and transportation corridors, the natural and
semi-natural shorelines are currently dispersed over 70 nature reserves of all sizes,
from the large national wildlife refuges to small wetland patches and several public
open spaces located directly along the shore. These parks and reserves are managed
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by at least 30 different entities, of which 3 are federal agencies, 3 state agencies, 21
local governments, and 3 NGOs. In contrast, all natural shorelines of the Tagus Estuary
are managed under two public agencies: the Tagus Estuary Nature Reserve
(protecting the more sensitive wetland habitat along the upper section of the estuary),
and Portuguese Environmental Agency (APA, which manages all other natural
shorelines). The exceptions are two large waterfront parks and a newly created local
reserve that are directly managed by municipalities (Figure 11).
Figure 11 – Entities involved in the management of Bay shorelines (Nature reserves
and public open spaces).
Equally, the instruments for protection of wetlands are diverse. Around the SF Bay
region, where the legal mechanisms available for controlling development outside
floodplains and existing wetlands are limited, the focus is on the rehabilitation of as
much of the remaining wetlands and salt ponds as possible. Most major restoration
efforts have focused on the conversion of salt ponds, which at one time took over as
much as 21,000 ha (Luken 1974) of former wetlands, especially on the South Bay. The
fact that these salt ponds have remained important bird habitats and fall within the
direct jurisdiction of the BCDC makes them especially appropriate for systematic
restoration.
The South Bay Salt Ponds Restoration Project (SBSPRP 2014) is especially significant,
constituting one of the largest wetlands restoration projects in North America.
Resulting from a large bulk purchase of ponds from Cargill Salt, the land was
purchased for $100 Million plus $143 Million in federal tax write-offs (Fischer 2007),
with funds from the State (California Department of Fish & Wildlife), Federal (US Fish
& Wildlife Service) and private patronage from 4 donors. The ongoing restoration
efforts are coordinated by the Coastal Conservancy through a partnership including
about 50 different entities, ranging from federal and state agencies to local city
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governments, special districts and private partners. The magnitude of the project
should be better understood if we take into consideration that the area of wetland
that will be restored through this project (~6,000 ha, including both former ponds
reconnected to tidal action and managed ponds) is more than the cumulative area
(~4400 ha) of all restoration efforts completed up to 2008 (Kondolf 2008, Interview
11).
In Lisbon, most conservation efforts have been linked, directly or indirectly, to the
preservation of the public domain (deriving from the old tradition of public trust over
navigable waters). The original standard of protection up to the highest astronomical
tide (HAT) was expanded with a buffer extending another 50m inland with a public
planning mandate and severe restrictions on new construction and modification of
land cover. All wetlands are thus included in the definition, although public-driven
irrigation projects, the expansion of port infrastructure, and a few industrial
developments were given the go-ahead up to the mid-20th century.
Since the 70s, new legislation started specifically addressing the protection of
wetlands, rather than simply lands under tidal influence, and this was reinforced with
the creation of the Tagus Nature Reserve in 1976, protecting the most sensitive
habitats and creating habitat management plans for adjacent lands. Further expansion
of the Public Domain regime created the concept of adjacent lands, which grant
limited planning mandates to public agencies. In the specific case of the Tagus Estuary
Management Plan, this buffer was set at 500m inland from the HAT line+50m.
The fact that most alluvial farmland has belonged to the State for most of its existence
and managed by a single entity, has promoted their sustainable management
(Madaleno 2006, Interview 4), such that these lands now also provide valuable habitat
and foraging grounds for several migrating bird species. The attitude towards
environmental protection is therefore mostly one, literally, of conservation. Small
restoration initiatives have been promoted, the largest one resulting from
environmental remediation from the building of the Vasco da Gama Bridge. The
Samouco Salt Ponds, which were already frequented by several species, were restored
and are currently managed so as to provide maximum benefit for shorebirds. The
recently created EVOA (Espaço de Visitação e Observação de Aves) is an artificial
wetland with a system of ponds targeted at several sensitive and iconic species and,
less than three years after being created, is already common roosting habitat for
several species (Interview 9).
In Figure 12, we compare the restoration projects for the Samouco salt ponds and the
South Bay Salt Ponds Restoration Project. While evidently having greatly different
scopes and dimensions, it is worthy to notice that the costs of intervention – and,
especially, the estimated cost per unit of area – are disproportionately greater for the
SF Bay Area intervention. While the complexity of the intervention may partially
explain the difference, other factors may weigh in, such as the cost of land acquisition
(as is the common practice for environmental protection efforts in the US), the cost of
infrastructure and coastal defense retrofitting (inevitable given that most ponds are
directly adjacent to urban areas protected by levees) and even an exponentially
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greater cost with permitting and documentation (even in when only public entities
are involved) (Interview 11).
Figure 12 – Entities and numbers involved in the South Bay Salt Ponds and the Samouco
Salt Ponds Restoration Projects.
SLR adaptation
Appendices A, B, and C contain the flood maps and resulting tables, which served as
the basis of the following analysis.
The San Francisco Bay and the Tagus Estuary will likely be impacted differently by
SLR. This is due to the fact that most of the effects felt on these urbanized shorelines
are not directly the result of SLR itself, but rather a consequence of the level of
exposure to SLR.
Around SF Bay, extensive development over landfill occurred, especially during the
first six decades of the 20th century. As such, a lot of highly vulnerable, and valuable,
real-estate development and infrastructure is located within a couple of meters of
current mean sea-level. In Lisbon, most development took place at higher elevations,
and most very low-lying land is occupied by farmland. In Figure 13, it is apparent that
at 1-m above present mean sea level (MSL) (roughly equivalent to today’s mean high
tide), mostly wetlands would be affected in both estuaries, but at only 2 m above
current MSL (at the high-end of estimates being advanced for the next 100-yrs),
considerable areas of urbanized lowland around the SF Bay would already be
rendered below MSL.
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This rise of 2m in sea level may take two to three centuries, but could be reached
much earlier if Greenland and Antarctic ice sheet meltdown is accelerated (Church
2008, Wong 2014). For this level of SLR, about 10,000 ha of non-artificial (not built,
e.g., agricultural, forest, open-space) land, and about 10,000 ha of artificial
(developed) would be inundated. About 60,000 ha of wetlands would likely be lost
unless given the opportunity to migrate, as the higher rates of SLR would likely be
incompatible with simple accretion (Titus 1990, Orr 2003, Stralberg 2011, Swanson
2013). Around the SF Bay, further SLR would disproportionately affect artificial
(developed) lands: over 28,000 ha of urban areas are less than 5m above present MSL
(~23,5% of all land affected) and as much as 55,000 ha less than 10m above present
MSL (~35,5% of total).
Figure 13 – Cumulative area of Wetlands, non-artificial, and artificial areas rendered
below mean sea level with sea level rise, in San Francisco Bay and the Tagus Estuary.
By contrast, the Tagus Estuary is flanked mostly by wetlands and rural areas. These
are areas across which rising seas (and, for that matter, migrating wetlands) can
transgress with little impact to human settlement. A 2-m rise in sea level would
submerge 25,000 ha of non-developed land (mostly agriculture), about 15,000 ha of
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wetlands (which may be able to accrete or migrate, Titus 1990), and less than 1,000
ha of artificial (built) land. This pattern would persist for higher SLR elevations, as
only about 2,000 ha of urban areas are located less than 5m above present MSL
(~3.2% of all land rendered below that elevated sea-level) and 5,000 ha below 10m
(~6% of total).
It should be mentioned that even this lower stage (+2m SLR) is significantly higher
than a present day’s King Tide for the SF Bay and, under that scenario, exceptional
high tides may be as high as 3-4m above current MSL. Past emissions have already
triggered processes which may be conducive of further increases in eustatic sea levels
of up to 7m above current MSL (IPCC 2014: 191). Although such SLR is not to be
expected for several centuries, it is worth noting that our simple analysis understates
the actual impact of sea level rise, because it reflects only the mean sea level, not the
reach of waves and storm surge, which could be considerably higher and would be the
relevant measure of impact, possibly driving the adoption of strong coastal defense
measures or phased retreat a much earlier stage than the actual inundation under
mean tide conditions.
These numbers disclose a major difference in both regions’ urban growth patterns:
while around the Tagus Estuary, urbanization took place mostly outside the flood
plain, around the SF Bay urban encroachment, including vast urban areas and major
infrastructure, have been built over landfill (Okamoto 2011, Luken 1974), and are
located within a couple of meters above current high-tide (Hanak 2012: 52). In
Chapter 2 we argue that this pattern can be traced to the evolution of legal standards
and the actual praxis of land-use planning and landfilling, which varied greatly
between both estuaries.
To this day, the Tagus Estuary enjoys a greater level of protection for lands located
above high-tide, with protection equivalent to that afforded by the Public Trust in
California extending up to the Highest Astronomical Tide, from which another 50m
inland is included in the Public Domain. Therein, all new construction is forbidden,
and it is additionally strengthened by a limited planning mandate for the adjacent
500m buffer, with strong restrictions on building outside existing urban perimeters.
Sea-level rise is being introduced in estuarine planning simply as an elevation above
the high-water standard, but will, according to the National Water Law, force an
expansion of public mandates with the rising waters. The SF Bay, besides being
already much more encroached by a ribbon of levees, infrastructures and urban areas,
is protected by a more limited planning mandate, which coincides with the limits of
the Public Trust. That is, it extends up to the Mean High Tide. The BCDC has an
additional limited planning mandate for another 30m inland from that line, but with
no police power except for the assurance of public access in new development.
Because region-wide planning bodies have no mandate above current high tide, the
only way to limit development in low-lying areas is to rely on tools such as FEMA
flood risk maps. These have an indirect power to deter development, through
influencing municipal zoning codes and through the deterrent of high flood insurance
premiums in exposed areas.
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3.4 Discussion
3.4.1 Land use challenges in face of rising seas
Although both estuaries experienced severe impacts from anthropogenic action, the
differences in the scale and, especially, the timeframes over which those impacts were
made, resulted in diverse outcomes.
Around the SF Bay, landfilling was concentrated over a single century, between the
mid-1800s and the mid-1900s. Although the definition of Public Trust in the US would
theoretically preserve tidal lands from alteration (Swanson 1975, Chapter 2), an initial
push to attract new settlers to the newly incorporated State of California saw
wetlands being auctioned with full property rights, first for farmland, then for salt
ponds. Throughout the first half of the 20th century, city governments opened lowlying lands adjacent to the shoreline to industry, commerce, and residential areas
(Luken 1974), developments that are now highly vulnerable to even modest rates of
SLR. While large areas of wetlands lost to salt ponds are being restored, the majority
of former tidal wetlands remain encroached by urban areas and infrastructure, such
that landward migration of tidal wetlands is not possible. Continued reduction in
sediment supply to SF Bay (Schoellhamer 2013) may impair the ability of wetlands to
keep pace with SLR merely through accretion (Orr 2003, Stralberg 2011, Swanson
2013). Therefore, identifying alternate paths for future wetland migration may be
crucial for future wetland sustainability (Interviews 5, 8 and 11).
In contrast, the Tagus Estuary experienced progressive alteration over 2 millenia,
during which time there was an incremental introduction of protection measures,
derived from medieval traditions and the protection of the Crown’s trust over
fisheries and navigable waters, which in turn can be traced to Roman, Visigoth and
Islamic traditions (Beirante 1998, Chapter 2). Having been expanded by 1864 to the
protection of all beds and shores up to the HAT line+50m (the Public Domain), this
already high standard was complemented in the past three decades with legislation
specifically protecting wetland habitat and a planning mandate over a transition
(adjacent) zone (established, for the Estuary Plan, at a further 500m inland from the
Public Domain).
The result is that very few buildings now exist in former estuarine lowland. Most
historically reclaimed land is still reserved for agriculture, with modern landfill
reserved almost exclusively for port areas and a few industrial plants. The bulk of
lands directly exposed to early stages of SLR is thus composed mostly of farmlands
created through the draining of wetlands, the Lezíria. The remaining natural wetlands
are expected to migrate and accrete, with deposition of sediment from suspended
sediment loads that remain high, though reduced from pre-dam levels. Studies on
specific sites indicate they will cope with SLR expected by the end of this century
(Duarte 2013, Silva 2008, Silva 2013). Because most Tagus Estuary wetlands are
flanked by agricultural lands, it should be possible for these wetlands to migrate
upland with rising seas (Titus 2011), without the complications that would ensue
along urbanized shorelines with multiple landowners.
77
Thus, SLR arguably poses a much greater threat to SF Bay than to the Tagus Estuary.
Around SF Bay, there is a greater awareness of potential impacts and more
involvement of civil society in efforts specifically addressing SLR (Heberger 2009: 43,
57, 71, 79, Interviews 2, 7, 8, 11), whereas in Lisbon the issue tends to be addressed
within the context of integrated environmental planning or municipal risk
management (Interviews 1, 3), and not as a separate issue.
3.4.2 San Francisco Bay Plan and environmental governance
The environmental planning frameworks and governance structures for both
estuaries are very distinct and present both advantages and drawbacks.
In reaction to the scale and rapid rate of environmental disruption in SF Bay, a strong
environmental movement emerged, with new laws and agencies tasked with nature
protection, adding to the complex of public agencies with very specific and narrow
mandates. The multiplicity of agencies and their often overlapping, sometimes
conflicting jurisdictions, results in a decision-making process for environmental
management of the SF Bay that is intricate, slow, and marked by efforts to defend
existing mandates. However, the highly scrutinized planning process yields
transparency and public awareness over the planning efforts and their results. There
is a strong emphasis on a well-grounded, and heavily negotiated, formulation of
regulatory and planning documents. The defense of mandates may inspire innovative
solutions for adaptation that do not interfere with the jurisdictional status-quo,
including establishment of specific partnerships dealing with the execution of a given
project.
We believe the process that led to the recent Amendment concerning Climate Change
serves as a good proxy for the peculiarities of the environmental planning process in
California and, more broadly, the United States. What was included in the Amendment
was severely limited by the virtual impossibility of expanding existing mandates and
jurisdictions beforehand. In fact, throughout the process, great effort had to be put
into reassuring stakeholders that no “power grab” would be attempted, and even
existing and solidly established mandates had to be reasserted. It became clear from
early feedback that some entrenched positions from interest groups and local
governments would compromise any solutions falling outside current jurisdictions
(Eichenberg 2013, Interview 2).
The protection by stakeholders of their own jurisdictions and interests has limited the
possibility of expanded environmental protection mandates for institutions such as
the BCDC. Perhaps the most obvious illustration of this is the limit of BCDC
jurisdiction to a strip of land 100-feet (30-m) from the current shoreline: it stands to
reason that the areas inland from this narrow coastal strip would need to be managed
in anticipation of future sea-level rise and landward transgression of the shoreline.
Being located just above current storm surges, they are extremely susceptible to even
small increases to SLR (Hanak 2012). Yet, the final document of the Amendment,
while for the great part consensual, had to be confined to the bounds of an
environmental planning mandate emanating from the mid-1960s, at the dawn of the
current environmental standards, according to a much more limited understanding of
78
the environmental processes involved, and at a time when the threat of sea level rise
had not yet been fully assessed.
The collaborative planning effort was very successful in articulating (or, rather,
navigating) strongly opposed perspectives on development priorities for the SF Bay’s
shorelines. Yet, the limited power of the main coordinating agency to enforce more
ambitious planning objectives may be perceived as a partial failure of the legislature
to re-shift the power balance to reflect the evolving challenges posed by greater
environmental awareness and the threat of SLR to man-made and natural
infrastructure.
The weakened position of the coordinating agencies renders them less capable of
balancing competing interests. It should be noted that, to adequately pursue their
mandates, this balance should not be established at, or even near, the least-commondenominator stances. Some stakes may not hold equal bearing, especially if they
necessarily subvert or undermine the plan’s objectives: being fair in the treatment of
competing stances does not equate to recognizing them all as valid. This was a major
issue with the CalFed initiative (water management in the Sacramento-San Joaquin
Delta, just upstream from the SF Bay) where federal and state agencies cooperated
with local agencies and stakeholders. Despite being deemed as a success in
collaboration and consensus-seeking (Fuller 2009) the planning effort was less
successful in achieving the desired policy ends (Bobker 2009) and ultimately failed to
adequately protect the common resource it aimed to protect (Hanemann 2009).
The expansion of planning mandates to the shoreline adjacent to the existing
jurisdiction, while unpopular among developers and some city governments, would
allow BCDC and other agencies to have much greater capacity to deter increased
exposure to SLR inundation, namely through limiting further development of existing
landfills, and encouraging non-structural coastal defense solutions. As BCDC’s
mandate regarding waterfront development beyond the high-tide line is limited to
little more than an “advisory” role and the enforcement of public access within
existing or proposed development areas, the amendment does not really provide the
mechanisms to significant change to the way urbanized shorelines evolve. It does
compensate this with a very clear definition of how its mandate will be pursued
within the areas where it indeed has a more active planning mandate (especially in
wetlands and salt ponds), and provides an extensive list of solutions, some of which
are very innovative, which all entities intervening on the shoreline are encouraged to
consider.
Among the several items listed, are included solutions for coastal defense that are less
damaging to ecosystems or design solutions that may increase the resilience of new
urban areas. The limited ability to enforce more ambitious solutions, which would
require an expansion of mandates, could be partially compensated by clear judicial
decisions regarding the interpretation of existing jurisdictions. Two such decisions
could come through the upholding of the ambulatory jurisdiction over the Public
Trust: given the doctrine regarding the Trust and the provisions regarding erosion
and avulsion, a progressive flooding of the shore would lead to a corresponding
79
redefinition of the high-water line. Even limited clarifications over jurisdictions and
mandates, as is the case with BCDC’s hypothetical claim to the “ambulatory nature” to
its public trust doctrine – albeit already asserted in the past by court rulings, as
mentioned by Eichenberg, (2010: 263-264) – or the expansion of its planning
mandate over areas located above mean-high tide, are unfortunately likely to face
fierce opposition and litigation from interest groups and municipalities (Fulton 2012:
92).
The Bay Plan is comprehensive and accurate in its depiction of the best state-of-theart knowledge regarding SLR adaptation and the range of adaptive solutions that may
be considered. Finally, through painstakingly assuring all stakeholders and agencies
involved are confident that the resulting regulations are sound, the Plan’s complex
and limited formulation is likely to lead to a much swifter and uncontroversial
implementation.
3.4.3 Tagus Estuary Management Plan and environmental governance
The Tagus Estuary Plan is the last planning element resulting from the incorporation
of the European Water Framework Directive into Portuguese national law. It will,
once approved, coordinate environmental management and water and shoreline uses
in and around the estuary. Therefore, it sets the blueprint for the integrated
management of the Estuary. The planning process built on the efforts conducted by
the Administrações de Região Hidrográfica in the creation of Coastal Management
Plans, and retained a strong emphasis on inter-agency collaboration and holding
public meetings so as to divulge the plan and its objectives and encourage a more
active public participation (as compared to what was the previous Portuguese
planning practice).
Nevertheless, and undoubtedly in large part due to the limited tradition of public
participation, most of what actually went into the plan was the result of direct talks
between the public agencies most vested in the Estuary’s management (the ARH, later
merged into APA, the Port of Lisbon, and the Nature Reserve) with consultation of
municipalities regarding site-specific issues. The collaboration between agencies was
unanimously mentioned as a very positive aspect of the planning process, and allowed
for several strategies to be coordinated, namely those regarding dredging, the
delimitation of SLR-induced flood maps, or the creation of clear standards for the
protection of all wetland habitats around the Estuary, with the identification of
priority interventions. What was achieved is actually a sound environmental
management plan backed-up by strong and recently expanded environmental
protection mandates and jurisdiction.
The final stages before the Plan’s final approval, though, have been marred by two
issues, which could be seen as relics of the previous paradigm of top-down,
deterministic, planning. The first is that, following a change in government and the
reorganization of the Portuguese Environmental Agency, the ARH was absorbed onto
a much larger institution and lost much of its recent capacity to directly engage
stakeholders and lead the planning process as a mediator. Concurrently, and perhaps
also bearing some relation with the Plan’s delayed publishing, is the outcry which
80
followed the top-down deterministic decision to build the new container terminal,
taken without consultation of the planning parties. More recently that proposal was
abandoned and the possible location of the deep-water container terminal on a former
industrial complex, in Barreiro, is now being studied. The Plan has, as a consequence,
been left in a limbo, pending final approval for over two years.
3.5 Conclusions
Both the SF Bay and the Tagus Estuary are faced with the eminent threat from SLR,
and therefore are already working on the introduction of adaptation solutions and
adaptive governance structures onto their respective environmental planning
instruments. Their ability to successfully respond to the challenge and incorporate
new planning frameworks and standards is a function of their past traditions and
current institutional and legal structures.
The SF Bay Plan can only limit development within a narrow strip above the present
mean high tide line, which is too limited to adequately address future sea level rise.
Landward migration of tidal wetlands cannot be facilitated because the plan cannot
prevent development in low-lying areas just above the present mean high tide line.
The Bay Plan’s Climate Change Amendment resulted from a very successful
collaborative effort to reach a consensus, but the price of consensus was no real
extension of the coordinating agency’s mandate or jurisdiction. As stakeholders adopt
entrenched positions, the resulting “least-common-denominator” solution may be
inadequate to face the future challenge.
The Estuary Plan is the result of a strictly top-down planning framework and
therefore depends on the will and drive of a handful of government agencies to see it
through. The lack of involvement of many stakeholders reduces the accountability of
decision-makers. Moreover, over-dependency on strict hierarchy may lead to
unilateral decision-making, such as inclusion of a new deep-water port, which was
strongly rejected by stakeholders and much of the public, thereby forestalling
adoption of the document as a whole. Greater engagement of the civil society in the
planning process could have avoided the current stalemate.
81
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al. (eds.)]: Climate Change 2014: Impacts,Adaptation, and Vulnerability. Part A: Global
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River, California, 1957 - 2001.” San Francisco Estuary and Watershed Science 2(2).
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4 EMERGING CONFLICTS IN IMPLEMENTING GREEN SEA LEVEL RISE
ADAPTATION: THINK GLOBALLY, SOLVE LOCALLY?
A version of this chapter will be submitted for review to
Mitigation and Adaptation Strategies for Global Change (ISSN: 1381-2386)
4.1 Introduction
At a time when several countries are adopting increasingly ambitious climate change
mitigation strategies, often levered on the curbing of greenhouse gas emissions, the
introduction of local adaptation measures is perhaps less consistent. Sea-level rise
adaptation, while being a seemingly unavoidable attitude in face of one of the most
pervasive, and indeed already noticeable, impacts of climate change (IPCC 2014, NRC
2012, EEA 2012a, Church 2008), is often addressed at the local scale with uneven
results.
Awareness of potential losses along more exposed coastlines is increasing with the
publishing of studies and increased media coverage, especially following natural
disasters (IPCC 2012, Carey 2011, Tollefson 2012, Wenger 2015), although not always
in the most effective or precise manner (Hulme 2009). Yet, most vulnerable shorelines
still lack a coordinated effort in articulating adaptation strategies and site-specific
interventions.
Complexity of local adaptation
Local adaptation lends itself to new challenges, posed by the peculiarities of local
government/governance, and the multiplication of private actors and interest groups.
Several environmental policies are typically adopted at a national scale, and then must
be implemented at the local level by multiple agencies. Therefore, the success of
implementation depends not only on the strength of the national commitment, but
also local governance (Douglas 2014). The impacts of climate change are “displaced
across scales and do not adhere to conventional governance boundaries” (Steele
2014), and alternative solutions for climate adaptation in urban contexts are often
expensive, affect the rights of private property owners, may require major changes to
existing planning systems, and constrain future property development options
(Bulkeley 2013).
This increased complexity is made all the more difficult to address because of the
limited resources local governments often have at their disposal. Past decisions made
by local governments now earmark significant portions of their budgets to the
maintenance of aging infrastructure and constrain alternative investment options, and
“path dependence” makes institutions reluctant to change past ways of doing
business, even in face of new requirements such as the need to articulate multiple
scales and an ever-increasing number of actors and interest groups (Matthews 2015).
Within the modern “sanitary city”, each of the specializations, “sanitation, street
services, planning – works in a bounded realm informed by specialised competences
siloed into departments and agencies” (Pincetl 2010: 46). Because of their
“centralized, rigid infrastructures, many sanitary cities exhibit limited capacity to
accommodate sustainable adaptations and practices” (Childers 2014). Thus, it can be
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difficult to work across specializations and establish the new governance platforms
required to coordinate the definition and implementation of adaptation solutions.
The expanded role of local governance
This should not be dissociated from an expanded role of local governments and,
especially, local governance/collaboration platforms, often including several local
actors, ranging from interest groups to environmental NGOs and individual citizens. In
the past, deterministic political decisions from centralized government institutions
were perceived as “the appropriate, legitimate and unchallenged vehicle for social
change, equality and economic development (…) responsible for environmental
protection” (Pincetl 2010), a role that came into question as social movements
addressed the lack of accountability and transparency of that model (Graham 2001).
Regional or local governance has taken up a big part of the role formerly performed by
centralized government agencies. Governance can, and should be, led by government
or regional public agencies, as they hold a coordinating role and should be able to
balance competing interests (Pierre 2000).
While the increasingly collaborative decision-making process is certainly beneficial in
terms of the transparency of planning efforts and budget decisions, we would
highlight three issues that may remain undervalued: non-profits are often treated as
proxies for residents’ interests where that may not always be the case (Pincetl 2010),
leading to a further disenfranchisement of the local community; private interest
groups may exert an undue influence over the outcome of the process through a
disproportionate capacity for lobbying and, through litigation, intimidation of other
stakeholders; and the outcome of consensus-seeking in collaborative decision-making
may in some cases result in a “least common denominator” type of solution that, while
acceptable to all parties, may fail to address the issue at hand (Hanemann 2009).
In the case of the United States (Svensson 2006) and, more specifically, California, the
added complexity of the legal and institutional arrangements surrounding adaptation
and local planning makes for a puzzle of overlapping jurisdictions and often unclear
mandates (Fulton 2012). The San Francisco Bay Area is home to over 100 local
governments and just the South SF Bay shorelines, where most case studies presented
ahead are located (Figure 14) are split between 4 counties (San Francisco, San Mateo,
Santa Clara and Alameda), 22 cities, 3 unincorporated territories, 3 flood control
districts, and a multitude of city departments and special districts dealing with flood
control, floodplain management, and infrastructure maintenance. Adaptation and
planning efforts risk becoming a “stovepipe system” due to a propensity towards
narrow mandates and the multiplication of single-purpose partnerships, where lack of
communication and articulation of efforts among agencies may lead to a duplication of
efforts and loss of efficiency.
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Figure 14 – Map of the San Francisco Bay, with locations mentioned in text.
Emerging conflicts in local adaptation: intractable conflicts or intractable
stakeholders?
As quite a few of these adaptation strategies have very concrete territorial
expressions, land-use conflicts often arise once they hit the “real world” The
regulatory and legal implications of local adaptation are exacerbated by the
specificities of land-use policy and property rights. Only during the implementation of
specific solution do many of the clashing stakes and more or less serious conflicts
arise. Given that many land-uses are incompatible with flood management and
environmental protection, decision-making often entails one or more of the
stakeholders having to forfeit their current or future stakes. Thus, entrenched
positions regarding relocation of uses, limits to future property and building rights, or
the allocation of resources (economic or otherwise) are prone to generate “intractable
environmental conflicts” (Campbell 2003, Gray 2003, Castro e Almeida 2013).
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These are types of conflicts where the entrenched opposition between some of the
stakes results in the near-impossibility of reaching a negotiated solution. While there
is a tendency to recognize all stakes as valid, especially within collaborative planning
platforms, we suggest that that is often not the case. Rothman (1997) described a
four-step framework for addressing conflict, which included a “resonance stage”,
where the "why" and "who" of the issue, according to all parties, is examined: as the
needs of the various parties are the underlying causes of the conflict and, by having all
sides hear the concerns of the other actors, it is expected that they might be able to
identify possible points of convergence, and thus expedite a solution. This is perhaps
an overly-optimistic perspective on the motivations of actors, as it assumes all stakes
as legitimate.
Curtin (2005:88) characterized five different types of stakeholders, one being the
“intractables”, or those intractably opposed. We would go further: some stakeholders
may be intractable simply because they have nothing to lose in the process, but a
whole lot to gain: Land with no prior development rights is naturally cheap; if
development rights are conferred onto that same tract through a judicial decision or a
change in zoning or detail plans, the potential profit for the property
owner/developer would be exponentially increased, while not being granted
development rights is of absolutely no interest to the developer. Therefore, some
apparently intractable conflicts could be attributed simply to the intractability of one
stakeholder with an unreasonable expectation.
Analyzing specific case studies where local adaptation to sea-level rise is already
underway, may provide good insights over the potential obstacles faced by the actual
implementation of sea-level rise adaptation solutions at the local scale, and which are
seldom fully addressed during the establishment of regional or national adaptation
strategies.
4.2 Materials and methods
We conducted an in-depth research into three case studies, all located in the San
Francisco Bay, California, USA (Charleston Slough, Redwood City Saltworks, and the
implementation of “ecotone zones” on the South Bay Salt Ponds). The selection of the
case studies was informed by a set of interviews with stakeholders and experts
conducted during previous research by the authors.
For each case study, we analyzed documentations and publicly-available reports, as
well as Bay-wide pilot projects concerning the incorporation of wetlands into flood
defense structures.
We complemented this with a thorough review of news media articles and published
opinion or marketing, in blogs or official websites. Additional inputs from semistructured follow-up interviews with policy-makers and environmental planning
professionals in the San Francisco Bay Area provided up-to-date information on the
current situation of each of the case studies.
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For each case study, we describe the events leading to conflict, identifying main
stakeholders, their stances, and major shifts in discourse and how it correlates to
relevant events in the process.
4.3 Results
Most of the South Bay shorelines were, during the early decades of the 20th century,
reconfigured into an expansive system of salt pond evaporators, consisting of multiple
levee-fenced ponds, most of them built at the expense of salt marsh (Goals Project
1999). Leslie Salt, by far the largest of the companies operating these ponds, still
owned over 21,000 ha of Baylands as late as the mid-70s (Luken 1974: 140, Okamoto
2011: 133). Several other structures, such as flood detention basins or the Moffett
Federal Airfield, were also built over former Baylands.
The 60s and 70s saw much-improved environmental standards, deriving from new
state and federal legislation and more rigorous interpretation of older standards.
Among others, in less than a decade several legal statutes were approved, such as the
Clean Water Act of 1972, complemented by the state’s water pollution legislation, the
state’s Porter Cologne Act of 1969 (Okamoto 2011: 158-160) and the passage of the
state’s McAteer-Petris Act of 1965, through which the state legislators halted
landfilling, increased scrutiny over dredging, and set-up the San Francisco Bay
Conservation and Development Commission (BCDC).
With the ceasing of most salt production activity around the South Bay, Cargill Salt,
which had absorbed all Leslie Salt ponds, entered a deal with the federal and state
governments to sell most of their ponds. The 15,000 acres (~6000 ha) of ponds were
purchased in 2003 for $100 Million, plus $143 Million in federal tax write-offs
(Fischer 2007), with funding from the State’s California Department of Fish & Wildlife
(CDFW) and Federal US Fish and Wildlife Service (USFWS), and additional
contributions from 4 private donors. The South Bay Salt Ponds Restoration Project
(SBSPRP 2009, SBSPRP 2014, Patton 2002) constitutes one of the largest wetlands
restoration projects in North America. The ongoing restoration efforts are
coordinated by the state’s Coastal Conservancy through a partnership including about
50 different entities, ranging from federal and state agencies to local city
governments, special districts and private partners.
Local adaptation around the San Francisco Bay has focused on two main types of
interventions: the upgrading of existing coastal defense structures, in articulation
with evolving United States Army Corps of Engineers (USACE) standards and Federal
Emergency Management Agency (FEMA) flood maps; and the restoration of wetlands.
The later was perceived as a priority from very early on (Williams 2001), as the
impounding, dredging, and landfilling of wetlands for development (Swanson 1975:
85) had reduced the regional provision of tidal wetlands to less than 10% of its early
1800s levels (Goals Project 1999, Williams 2001, Madsen 2007, HDR 2014).
Much of the restoration effort has concentrated on the establishment of salt marsh
habitat on former salt ponds, through the tidal reconnection of the ponds. Slow
sediment fixation typically allows for a natural accretion to occur, up to the point
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where marsh vegetation becomes established. Concerns with capacity of marshes to
keep up with the rates of SLR expected towards the second half of the century have
triggered studies into solutions that would permit future migration, or at least
promote marsh accretion.
Given that virtually all South Bay marshes are confined on their landward limit by
landfills protected by seawalls, levees, and other coastal defense structures, the
upgrading of these structures and wetland restoration efforts are, at least within the
constraints of South Bay’s land use patterns, increasingly assumed to be
complementary, rather than opposed, strategies: ecosystem-based (or green)
approaches to flood management may help improve the protection, cost-effectiveness,
and co-benefits of levees (Wenger 2015, Battalio 2013), with wetlands instilling them
with a level of flexibility and natural adaptability absent in strictly man-made
structures, while at the same time providing an added wave attenuation
capacity(Lowe 2013).
Through its past experience in marsh restoration and ongoing projects, the San
Francisco Bay is an early adopter and leading research center for this type of green
adaptation solutions. Comparable solutions are known in the region by different
names, most notably as horizontal levees, (Battalio 2013, Lowe 2013, Zimring 2015),
or as transitional wetland-upland ecotone or upland transition zones (Goals Project
1999:A-56, PWA 2004, ESA-PWA 2012, HDR 2014).
4.3.1 Adaptation studies and programs in the San Francisco Bay Area
The complex institutional framework has already addressed the threat posed by SLR
through numerous documents, reports and pilot projects, led by all levels of
government and through several multi-level interagency partnerships. Many of these
studies focus only on the outlining of regional adaptation strategies or propose
preferable courses of action, but there are an increasing number of programs leading
into actual implementation of SLR adaptation solutions. Following are a few examples.
Federal Level
Federal agencies and regulators often engage in more direct collaboration with local
governments in the design and implementation of projects, with the USACE,
Environmental Protection Agency (EPA), FEMA, USFWS or NOAA, being present with
varying degrees of involvement in several planning, restoration and flood protection
projects (ACFCWCD 2015). The National Research Center published a report on the
expected impacts of SLR in the Western states (NRC 2012) and USACE’s San Francisco
District is leading the South San Francisco Bay Shoreline Phase I Study (HDR 2014).
Partnerships between federal, state, and local institutions
Several multi-level partnerships between local, state, and federal agencies have
worked on specific projects or in publishing SLR adaptation studies and reports.
“Adapting to Rising Tides” (BCDC 2015a) is an ongoing project focused on SLR
vulnerability and risk assessment and adaptation along the Alameda County
shorelines, and results from collaboration between the federal National Oceanic and
Atmospheric Administration (NOAA) and the BCDC, a state agency. The San Francisco
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Estuary Partnership (SFEP), a multi-level agency coordinating restoration actions at
the regional scale, spun-off from EPA’s National Estuary Program, to promote interagency cooperation and facilitate the identification of public and private grants and
other funding opportunities. SFEP is one of the leaders in the Bay-wide Flood Control
2.0 program (SFEP, n.d.). Another example of these multi-level partnerships is CHARG
- Coastal Hazards Adaptation Resiliency Group (CHARG 2015).
State level
Quite a few studies on the impacts of SLR have been produced or sponsored by the
state’s legislators and agencies, such as “A Slow Moving Emergency” (Gordon 2014),
by the California State Assembly Select Committee Sea Level Rise and the California
Economy, or the 2013 report “The Impacts of Sea Level Rise on the San Francisco Bay”
(Heberger 2013), which focuses specifically on the SF Bay.
The BCDC, tasked with the protection of the San Francisco Bay, has published several
reports on the topic, such as the Living with a Rising Bay report (BCDC 2011a), and
has recently amended the Bay Plan, guiding the protection and regulation of uses
within the Bay’s Public Trust, so as to reflect the latest knowledge regarding SLR
(BCDC 2011b).
Local level
Santa Clara County established a local partnership to expedite implementation of local
climate adaptation measures across city borders, the Sillicon Valley 2.0 (SCC 2015).
The San Francisquito Creek Joint Powers Authority, is an example of the complex
partnerships that are often purpose-created in the region, coordinating efforts from
two counties (San Mateo and Santa Clara), three cities (Palo Alto, Menlo Park, and East
Palo Alto), and two regional water agencies (Santa Clara Valley Water District and San
Mateo County Flood Control District) within a watershed that straddles the boundary
between them. It is the local sponsor in the USACE’s San Francisquito Creek General
Investigation Study.
The City and County of San Francisco has its own Floodplain Management Program
(CCSF 2015) and is upgrading its standards to address SLR. Other cities have their
own SLR studies and plans, such as the City of Palo Alto’s Threat and Hazard
Identification and Risk Assessment (OES 2014) or the City of Mountain View’s
Environmental Sustainability Action Plans 1 & 2 (CMV 2009, 2012).
Several environmental NGOs and public/private partnerships have established
programs to promote environmental protection and research green SLR adaptation
solutions. The San Francisco Estuary Institute (SFEI), a science institute dedicated to
aquatic studies for the Bay, has been pioneering research on innovative SLR
adaptation solutions, especially regarding the incorporation of wetlands in the mix of
coastal defense solutions. Among the more active NGOs are Save The Bay, The Bay
Institute, The Nature Conservancy, and the Audubon Society.
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4.3.2 Charleston Slough
Figure 15 maps Charleston Slough and its surroundings. Numbered references in the
text refer to this map.
The Inner Charleston Slough (ICS), along the border between the cities of Palo Alto
and Mountain View, in Santa Clara County, was separated from the Outer Charleston
Slough by a berm (1), built by the Spring Valley Water Company in 1923. It was tidally
connected to the Bay through a 60-in (~1.5 m) culvert, and thus hosted tidal
marshland. After much stricter limitations on pollutant and sewage emissions onto
public waters were enacted in the 1960s and early 70s, the bi-products of salt
production could no longer be directly disposed of into the Bay. Leslie Salt, the owner
of the Slough and adjacent salt evaporators, resorted to storing salt brine in ICS, and
cutting off the existing tidal connection with the Bay by replacing the existing culvert
with a smaller one, at a higher elevation (1). The continuous water impoundment led
to most of the vegetation being killed off by prolonged submergence (Hydroikos
2001).
Figure 15 – Map of the Charleston Slough and surroundings.
BCDC had introduced, in its Bay Plan, the provision for a “zero-net-loss” policy for
Baylands and marshes. As such, the killing-off of ICS’s marshes was seen as a violation
of McAteer-Petris Act. As soon as BCDC was made aware of the unauthorized culvert
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replacement and its consequences, it required Leslie Salt to restore the ICS to full tidal
action and ensure the fixation of 40 to 60 acres of tidal marsh. (BCDC 1999)
Leslie Salt proposed to convey full property of the ICS to the City of Mountain View,
which would inherit the responsibility for restoring the marsh. In 1978, Leslie Salt
operations were taken over by Cargill, which kept the tidal gates shut. In 1980 the City
of Mountain View took title of the ICS and proposed an amendment to the restoration
scheme: rather than fully restoring tidal action, the City proposed to introduce a water
control gate, allowing for a daily tidal range of 0.85 to 1.10 ft. This reduced fluctuation
would dispense further upgrading of the levee protecting the Palo Alto Flood Basin
(3). BCDC authorized this through an amended permit, as long as the City ensured at
least 30 acres of marsh would establish within 7 years. The new gate never worked
properly and the insufficient tidal range in the ICS impeded the fixation of marsh
vegetation (BCDC 1999).
To comply with BCDC’s permit, the City started working on a new restoration plan in
1988. Finalized in 1996 (McCabe 1996) and implemented through to January 1998
(Hydroikos 2001), the project replaced the gate with six self-regulating culverts at a
lower elevation (therefore enhancing tidal fluctuation in the ICS) , raised the levee
between the Inner and Outer Sloughs (1), and slightly upgraded the lower levee
separating the ICS from Cargill’s Salt Pond 1A (7), to the east.
As the 7-year timeframe for the establishment of marsh vegetation had not been met,
BDCD now pushed for the full restoration of 53 acres of vegetated tidal marsh. The
tidal range, while much greater than before, was still over a foot less than predicted,
and thus unable to provide ideal conditions for the accretion (elevation build-up
through the natural fixation of sediment flooding in from the Bay) and spontaneous
colonization by salt marsh vegetation. Additionally, early colonization by an invasive
species of cordgrass required the use of pesticides in 2006 and 2007 and the desirable
native cordgrass has proven difficult to recruit (Coats 2012). As the achievement of
the 53 acre goal appears to be taking far longer than expected, the BCDC has been
requesting further action from the City, which would plausibly include the
requirement of full tidal reconnection between the Inner and Outer Slough so as to
expedite marsh expansion, as per the original permit (BCDC 1999).
In the meantime, adjacent tracts have seen much change (Figure 15). To the West, the
former Mayfield Slough has been transformed into the Palo Alto Baylands/Palo Alto
Detention Basin, a regulated pond with significant areas of salt marsh which doubles
as an essential flood detention basin protecting the City of Palo Alto. South of the ICS,
and separated from it by a wide levee (4), is the Shoreline Park, Country Club, and the
Sailing (or Shoreline) Lake, all built over landfill and experiencing significant
subsidence.
To the East, Salt Pond A1 was transferred to the Salt Bay Salt Ponds Restoration
Project (SBSPRP). SBSPRP has plans to open Pond A1 to full tidal action (SBSPRP
2014), and has proposed to include Charleston Slough in the project by opening a
breach in the levee separating them (7). The City of Mountain View is concerned this
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may lead to a very fast flushing of the already significant sediment that has built-up in
the ICS, as the Pond A1’s base level is currently several feet below that of the ICS. As
such, achieving BCDC’s restoration goals within the ICS would likely prove impossible
for several years after that reconnection. To further complicate matters, this tidal
reconnection would mean that the levee protecting the Shoreline (4), as well as that
separating ICS from the Palo Alto Basin (3), would then be exposed to full tidal action,
whereas now they are buffered by the managed ponds. This would require extensive
upgrading, especially in the case of the Shoreline levee (4). With sea-level rise already
forcing the revision and expansion of flood protection standards around the Bay, the
upgrading would have to meet much stronger requirements than those that led to its
initial creation.
A seemingly more trivial issue, but one likely to produce significant public outcry, is
that the Sailing Lake, a purely recreational manmade lake within the Shoreline Park, is
sustained by daily replenishment through a pumping station located at the southwest
end of the ICS (5). If the Slough is tidally reconnected, it is more than likely that the
pumping station intake would have to be relocated or reconfigured if the Lake were to
be maintained at its current water circulation level.
With so many conflicting interests, and such a large number of federal (USACE, EPA,
USFWS, FEMA), state (BCDC, CDFW, Coastal Conservancy), and local (City of Mountain
View, City of Palo Alto, Santa Clara Valley Water District) agents involved, it is no
wonder that the decision-making process may appear untenable at times.
Nevertheless, there are already direct communication lines between several of the
involved parties that prove invaluable in achieving these goals. Although only held
once a year, bilateral or multilateral forums, such as the yearly SBSPRP Regulatory
Workgroup Meeting, address the negotiation of mutually-beneficial solutions
(Interview 13).
The City of Mountain View is comfortable with the possibility of having the ICS tidally
reconnected, but obviously only if the BCDC is in agreement with the solution and thus
lifts, or extends, the deadline for reaching the current marsh restoration goal within
the ICS. The City is equally worried about potential impacts over existing flood
protection structures and, especially, with potential liability over a weakened
protection provided by the levees separating the ICS from the Flood Basin (3) and the
Shoreline (4). It would likely struggle to reach a solution where the costs of upgrading
those structures and finding a solution for the pumping station would be shared
among the interested parties.
SBSPRP is interested in achieving the maximum benefits in terms of habitat provision
from the restored ponds (Interviews 8, 11, SBSPRP 2014). By combining the alreadyplanned tidal reconnection of Pond A1 to the Bay with the breaches that would also
reconnect ICS to full tidal action, the medium- to long-term potential would be greater
(although relatively small, incorporating ICS would significantly expand the total area
available for immediate restoration in the Western Alviso Ponds). The BCDC has
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remained consistently adamant in its requirement that the 53-acres of restored marsh
goal be met within the limits of the ICS, and has expressed so to the City before.
Nevertheless, recent information (Interview 13) points towards the possibility of a
mutually-beneficial, if slower and more complex, combined restoration of Pond A1
and ICS, contemplating equally an upgrading of the Shoreline and Palo Alto levees.
4.3.3 Redwood City Saltworks
The bulk purchase, in 2003, of Cargill Salt Ponds, mentioned above, left out a few
areas. One such tract was the Redwood City Saltworks (Figure 16) which, at the time,
remained an active salt production facility. In 2007, David Benjamin, a state
administrative law judge found the 2003 valuation of the South Bay Salt Ponds ($100
million in cash and $143 million in federal tax write-offs) to be largely based on
“unfunded assumptions” during the land’s appraisal. One such assumption the judge
found inflated was the valuation of the 350 acres around Cargill's Redwood City plant
at $78.5 million. This presupposed a development plan of thousands of new
apartments, stores and office buildings. The appraisal failed to highlight that such a
valuation was conditional to such a development being permitted which, as we will
discuss ahead, is very far from a given. The judge thus concluded that the appraisal
"provide[d] no factual basis on which to conclude that it is reasonably probable that
the public agencies would permit the proposed mixed-use development."» (Fisher
2007).
Coincidentally or not, Cargill announced in 2006 its plans to phase-out salt production
in Redwood City and partners with a developer, DMB, in outlining the future of the
Saltworks. DMB mass-mailed all Redwood City residents encouraging them “to
participate in the development process and asking for ideas on ways to use the 1,433
acres.” (Louie 2006).
Environmental NGOs, especially Sierra Club and Save The Bay, started contesting the
proposed development as soon as DMB disclosed their “50-50 Balanced Plan Project
Proposal” for the Saltworks, by renowned architect and urbanist Peter Calthorpe. A
lead proponent of “Smart Growth”, mainly focused on compact, multifunctional,
transit-oriented development, the architect published a defense of his project
(Calthorpe 2009), in which he characterized the ponds as a “1,400-acre moonscape, a
century-old industrial salt "factory without a roof" that could continue to make salt
indefinitely.” This assessment is vehemently contested by the NGOs, which
emphasized that, even in its abandoned state, the ponds provide valuable habitat, and
lend themselves to full restoration as wetlands. Several bloggers and journalists
picked up on the story in the following years, many of which emphasizing that the
project prevented restoration of former wetlands (Shigley 2009, Jones 2010, Parman
2010).
During 2010, DMB campaigned heavily to have the project approved by the City’s
planning commission or simply through a local ballot that would authorize the
development (Elinson 2010). The debate and challenge to the project did not fade,
however, and in the following years Save The Bay, BCDC, and Calthorpe, debated the
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future of the saltworks on several media, including a SPUR-sponsored debate. (Baume
2011). Following several concerns put forward during public hearings and the
environmental review process (RCPC 2015), the Saltworks Project application to the
Planning Commission was withdrawn in May 4, 2012 (DMB 2012).
Figure 16 – Map of the Redwood City Saltworks.
In 2014, Calthorpe mentioned in a radio interview that there was still room for a
compromise that included development of the saltworks (KZSU 2014) and, soon after,
DMB announced it was working on “a revised and “scaled-back” project that provides
for restoration of the majority of the 1,400-acre property” (DMB 2015). Save The Bay
has made it clear that they will keep fighting these development proposals (Lewis
2015).
Jurisdictional determination under the Clean Water Act
In the past few years, DMB has shifted its efforts towards attempting to exclude the
Saltworks from under the purview of the federal and state regulations regarding
wetlands and tidal waters. To achieve this, they are reconfiguring the project so that
development is concentrated on the western-most portion of the site, that has been
disturbed for longer (DMB 2012), and are trying to get a determination of no100
jurisdiction under the Rivers and Harbors Act of 1899 (RHA) and the Clean Water Act
of 1972 (CWA). Both are federal statutes protecting the Waters of the United States.
In 2010, a preliminary jurisdictional determination by the USACE found the site to
belong to the Waters of the US, and thus subject to the provisions of the RHA and CWA
(USACE 2015). Two years later, in May 2012, DMB made the bold move to forfeit
further preliminary analysis and requested a final, and binding, approved
jurisdictional determination of the extent of jurisdictional waters of the United States
and navigable waters occurring on Redwood City Salt Plant project site. Save The Bay
would later denounce this as an attempt to have the Saltworks declared as nonjurisdictional under the CWA (Lewis 2015): if successful, the move would exclude the
land from the federal protection granted to the Waters of the United States and, at the
same time, preempt most environmental objections to the project, especially those
regarding the proposed dredging and filling of former wetlands.
The determination of jurisdiction under the CWA is shared by the USACE and the EPA.
Typically, the EPA relinquishes its power onto the USACE. After initially doing so with
regards to the Saltworks23, the EPA elected on the last available date to make the final
CWA jurisdictional determination. This uncommon decision was made after the EPA
learned from the USACE that it would allow the exemption, under a “confirmed nojurisdiction” determination, regarding both the CWA and the RHA, thus reversing its
own 2010 preliminary decision (USACE 2015). USACE discussed at length, in its
memorandum regarding the binding RHA decision and the proposed ruling regarding
CWA and the attached legal principles (Stockdale 2014), that most of the eastern
portion of the site had been historically above Mean High Water (MHW), even where
the previous land cover had been tidal salt marsh, and with the exception of a couple
of double-sided sloughs, all land was considered outside RHA jurisdiction by having
been above MHW at one time. While making it clear that the CWA jurisdiction is a
distinct question from the RHA jurisdiction, the Corps concludes that the liquid pickle
and bittern on the site is not “water”, as it does not clearly fall within any of its seven
categories of “waters of the US). Therefore, it argues that these liquids are not subject
to CWA jurisdiction. It further dismisses the possibility of determining jurisdiction on
the basis of the land being composed entirely of former salt marsh stating that “the
site has been highly altered to facilitate the salt manufacturing process. This alteration
of the site and a century of industrial salt making have eliminated any trace of the
prior marshland or wetland character of the site.” Additionally, USACE argues that
there is no normal flow of tide, that the liquids are intentionally hydrologically
separated from the Bay’s waters.
Being produced at the Washington, D.C. USACE headquarters, this legal interpretation
was met with objections even by the Corps’ own San Francisco District. It was by no
means an uncontroversial assertion (Lewis 2015, Rogers 2015) as the traditional
23 In
an email message dated 30 October 2012, the EPA stated that the Corps should follow normal
procedures and make the approved jurisdictional determination (AJD) under both the RHA and the
CWA.
101
assumption, based on Froehlke (1978) and others, is that the water impounded
behind levees is indeed the same as the Bay’s, and thus subject to federal protection.
The level of disturbance and/or chemical alteration appears to have had no bearing on
that precedent-setting decision, and has been invoked numerous times in land
disputes around the Bay’s shorelines.
While pending, this decision has been perceived as a major threat not only to the
aspirations of environmental NGOs in having the site restored, but equally in
establishing a potentially game-changing precedent for future land disputes
(Silverfarb 2015, Speier 2015). It was also reported as a fight to uphold the standard
of what constitutes Waters of the US under the CWA and, consequentially, wetlands
subject to Federal protection and potential restoration (Rogers 2015, Myrow 2015).
EPA stepped-in immediately before the deadline for USACE’s determination to be
released, in April 18, 2015 (EPA 2015). Ultimately, the EPA may yet decide not to
uphold a CWA jurisdiction over most of the Saltworks. Nevertheless, the simple fact
that it asserted its right to rule on the matter (and, potentially, overrule the Corps’
assessment) could easily be interpreted as an at least partial disagreement with
USACE’s assessment. The EPA is expected to make the final ruling early in 2016.
4.3.4 Adapting to adaptation: restoration standards require changes to Bay
protection standards
As mentioned before, the South Bay Salt Ponds (Figure 14) is the largest wetland
restoration project on the West coast of the United States (SBSPRP 2009, SBSPRP
2014). It is also costly, with early estimates for the complete restoration pointing to
over $200 million, excluding contingency costs and the costs of acquisition (Patton
2002: 22). To qualify for state funding, several restoration actions proposed for Phase
2 of the project will have to be demonstrably resilient in face of SLR and, in the
heavily-encroached setting of the South Bay ponds, that entails the inclusion of ramps
along the shoreline where levees currently block wetland migration. These 30:1
ramps are a practical application of the “ecotone transition zone” concept mentioned
above (Battalio 2013, Lowe 2013, Zimring 2015, Goals Project 1999:A-56, PWA 2004,
ESA-PWA 2012, HDR 2014). The principle is that if the ramp is designed with a gentle
slope within the tidal range, it will allow the creation of a fringe of salt marsh
vegetation on the landward edge of restored ponds that may expand progressively
through natural accretion as sediment slowly builds up on the tidally-reconnected
ponds (Figure 17).
Additionally, these shallow slopes on the Bay-ward side of levees can be readilyincorporated into the design of the necessary upgrading of existing levees and other
flood protection structures (HDR 2014). With the expected rates of SLR, most
shoreline defense structures protecting the South Bay will require extensive
retrofitting simply to keep-up to FEMA’s 100-yr flood protection standard.
102
Figure 17 – Levee with ecotone zone (adapted from USACE2015: Figures 3.6-3 and 3.64).
BCDC’s discomfort with rubber-stamping fill
These ramps, while well-received by most local actors (namely the project-leading
Coastal Conservancy, but also USACE and flood control districts) technically
constitutes an instance of Bay filling, as the 30:1 ramp requires some material to be
deposited along the levee within the jurisdiction of the BCDC. Going back to this
agency’s original mandate, halting Bay fill was a foremost concern, as it had been
responsible for the destruction of enormous expanses of wetland habitat up to the
1960s. It is therefore no wonder that the BCDC will thread carefully with regards to
any alterations to its current “zero-net-loss” policy. Thus far, small pilot projects
including ecotone zones, such as the Oro Loma test site (ESA-PWA 2012), have been
permitted on a case-by-case basis and BCDC has been reluctant in accepting from the
get-go the incorporation of ecotone zones in larger project sites. The agency is likely
concerned that a rash adoption of a new policy regarding fill could open a loophole
and usher in attempts to push through future projects proposing new landfill,
unrelated to the restoration of wetlands.
Nevertheless, as the several stakeholders become more familiarized with the ecotone
zone solution, there is the possibility that the agency will revise its policy regarding
this very specific solution (Interview 13). It has begun the 18-month, NOAA-funded,
Policies for a Rising Bay project (BCDC 2015b) through which BCDC’s Commission Fill
Policies Working Group will identify and eventually propose adaptation of the
agency’s guidelines regarding bay fill.
4.4 Discussion
The types of conflict emerging from local adaptation efforts around the San Francisco
Bay may be organized into three major groups, based on the stakeholders involved:
103
conflicts between two or more public stakeholders, between public and private
stakeholders, and between two or more private stakeholders.
4.4.1 Public vs. Public
Too many entities with overlapping jurisdictions and limited mandates may lead to
the “stove piping” of agencies and departments. Without proper articulation, they may
independently address the same issue and reach diverse solutions based on their
narrowly scoped mandates and missions, which may enter in conflict during
implementation (as was the case with Charleston Slough). Or, quite the opposite, it
may equally lead to situations where all agencies take passive stances waiting for
someone else to take the lead in tackling a given problem: too much involvement may
lead to entropy, too little, to inertia.
Some of the overlap that would be apparent while looking at the regional scale,
becomes less obvious once each area of the Bay is analyzed individually. For instance,
while the federal EPA is taking a big role in the East Bay adaptation studies,
coordinating directly with the Alameda Flood District, the South Bay adaptation
efforts are mostly being coordinated by the state’s Coastal Conservancy, even if they
include several other state, federal and local agencies. The San Francisquito Creek
Joint Powers Authority would be another example where, due to the site’s location
along the border between two counties, a partnership among adjoining municipalities
and flood agencies was deemed more efficient.
While that is not always the case, all the examples analyzed include public agencies
from at least three levels of government (federal, state, and local). The ample
provision of inter-agency “task forces” or “partnerships” helps tackle many complex
problems, but there is room for improvement. For instance, at its inception, BCDC was
set up as a coordinating agency, and the Commission includes commissioners
representing local governments, state and federal agencies, and even local interest
groups.
Since the 1960s, though, quite a few other agencies have been granted mandates that
would require coordination at the regional level, but bilateral communication is often
reserved for infrequent meetings; in the specific case of the South Bay, this often
means that relatively simple revision or conciliation of standards or proposed
solutions may have to wait for a new scheduled meeting to take place. For some
bilateral decision-making, this may represent a delay of several months. The rapidity
of change and innovation in regional adaptation efforts would likely deserve a more
permanent and regular communication platform so as to permit expedited
coordination.
Two entities tasked specifically with the Bay’s conservation may play an even more
relevant role in the articulation and knowledge-sharing among the several public
actors, SLR adaptation, and wetland restoration projects: The San Francisco Estuary
Partnership could have a more active role in streamlining the articulation of federal
and state funding, while the BCDC is, by its very nature, the prime coordinating entity
for San Francisco Bay. As of late, the BCDC has been more associated with its
104
regulatory role but that hasn’t always been the case. Although its full planning
jurisdiction extends only to the limits of the Bay’s Public Trust (MHW), the BCDC has a
dual body, with a permanent planning unit staff, but also a commission including in in
its roster representatives from local governments, special districts, and state and
federal agencies with stakes on the Bay and its shorelines. Reinforcing (or rather,
restoring) the latter’s role as the foremost coordinating and planning platform in the
Bay may help reduce redundancy and increase efficiency.
Two of the cases presented before have a “silver lining” of sorts, in that most public
actors seem to be increasingly aware of this need to coordinate and articulate
common solutions. Both in Charleston Slough and in the adoption of Ecotone Zones,
“public v. public” conflicts never fully expressed themselves, but were rather on the
verge of occurring, unless there was a negotiation or revision of standards and
designs. Once frank discussion among all public actors was initiated, consensual
solutions appeared easy to achieve.
4.4.2 Public vs. Private
The Redwood City Saltworks dispute is much less likely to have a straightforward and
consensual solution, and the involvement of strong private stakes is at the heart of the
dispute. One major element that is typically absent from public v. public disputes is
the threat of litigation, especially from well-endowed developers or interest groups.
While it may be seen as a somewhat minor problem in other constituencies, in the
United States, and especially in California, the looming prospect of long and costly
legal battles may lead to an overly cautious and conservative approach by public
agencies (Fulton 2012: 92).
Public agencies have equally become somewhat disavowed in the transition from
deterministic government to collaborative governance (Pincetl 2010). With limited
resources and often lacking the clear legal mechanisms necessary to pursue their
mandates, public agencies are left with the nearly-impossible task of fulfilling their
public duty without the necessary means and power.
Wetland restoration actions have a very concrete spatial expression. As such,
permitting and planning agencies need land for the restoration work, but the land use
authority ultimately falls on local municipal governments. These governments are left
sandwiched between powerful developers’ motivations, the local government’s own
interest in economic development and (especially in the Bay’s red-hot real-estate
market) meet housing demand, and the restoration objectives.
Also, some of the vested interests of public agencies are not necessarily easy to
quantify: “Because ecosystem services are not fully ‘captured’ in commercial markets
or adequately quantified in terms comparable with economic services and
manufactured capital, they are often given too little weight in policy decisions.”
(Costanza 1997), although that is not as clear-cut when flood control is an integral
part of the restoration plan. The public benefits of these long-term plans, though, will
tend to be protacted for several decades.
105
In contrast, the potential economic gains some private parties may derive from land
use decisions may be quite extraordinary and easy to quantify. Luken (1974) assessed
that the process of transforming SF Bay’s wetlands onto “fastlands” (developed
landfill) could equate to as much as a 75-fold increase in land value. It should be
pointed out that some of these wetland tracts around the SF Bay were purchased in
auction for as little as $1 per acre (i.e., $2.50/ha). Besides, it may yeld short-term
benefits within a few years, and align more clearly with near-sighted political
objectives. The likely escalation of costs in the maintenance and reinforcement of
flood protection and infrastructure with SLR is too often left unmentioned, although it
is a growing concern around the region (Stark 2015).
Looking more closely at the Saltworks example, even if that property was to be valued
at the presumably inflated average value for all of the SBSPRP ponds – which stood at
around $6,600/acre – that would still be about 34 times less than the $225,000/acre
valuation for the Saltworks plot that was cited (and much-criticized) by Judge
Benjamin (Fisher 2007). Simply put, assuming the Saltworks, or some areas therein,
may be converted to real-estate, rather than reverted back to wetlands, could
exponentially increase its value. It is no wonder, then, that the owner and the
developer would be willing to fight prolonged and expensive legal battles to establish
even partial building rights over an otherwise “worthless” property.
The conversion of tidal wetlands into fastlands, while being at odds with the
principles of the Public Trust Doctrine, was determined not to be subject to reversion
(Briscoe 1979, City of Berkeley v. Superior Court 1980). That applied to already
developed landfill, though, under the principle of fait accompli.
Salt ponds are different. They were never fully developed, and remained subject to
regular inundation by Waters of the US. Also, unlike most fastlands, no development
rights over these ponds were ever legally recognized in the past. Whether they should
be considered as part of the Public Trust or not is still a matter of controversy, as is
indicated by USACE’s decision for the Redwood City Saltworks. The relevance of the
final decision, which falls now in the hands of the EPA, is that it will not only decide
the fate of those particular salt ponds, but equally establish legal precedent for similar
cases, around the Bay and indeed across the Country.
In other constituencies, legislation is frequently revised and expanded to address an
evolving public agenda; in the United States, however, the protection of natural
resources, especially from the 60s onwards, has often been achieved with recourse to
bold interpretations of old statutes, including what some have characterized as a very
liberal interpretation of narrow original mandates (Lazarus 1985). While this has
worked for the past few decades, it also renders the whole logic of environmental
protection vulnerable to challenges such as that posed by the Saltworks project.
Whether former wetlands are to be restored or not should be an explicit public policy,
and not the object of semantic debates over the letter of the law. As private
stakeholders become aware of some fragility in the original legal interpretations that
have set the modern standards and doctrines, litigation on jurisdictional or zoning
106
decisions has reached the point where a few agencies now take every possible
precaution in avoiding it.
The National office of the USACE presented well-grounded arguments on why it would
not declare the Saltworks jurisdictional under the RHA and the CWA. Yet, its
interpretation is extremely cautious: at all steps of memorandum justifying its
decision (USACE 2015), one can infer how preoccupied USACE was with the
possibility of taking a stance that would render them in a position where they might
be challenged in court, and establishing precedents that would affect other areas (they
specifically mention New Orleans in their memorandum). The regional EPA office
likely has very different concerns, namely that of opening up other disputed Bay
shorelines to development in ponds behind levees if they are to be exempted from
jurisdiction under the CWA.
4.4.3 Private vs. Private: for-profit vs. non-profit
Litigation and liability are a necessary element in sustaining a balance between the
public, or common, interests, and the preservation of private rights. Abuse of this
legitimate legal recourse, on the other hand, often conducts to situations where the
public agencies or governments may become fearful of entering in disputes with wellendowed private parties and be forced into long, trying, and expensive legal battles.
While several public agencies have very limited resources (human or otherwise) to
dedicate to long legal battles, and are therefore in a fragile situation when faced with
litigation from wealthy private developers, corporations or interest groups, the
balance is somewhat restored through the strong support from environmental NGOs,
especially in more liberal constituencies such as the Bay. Well-established, and
respected, NGOs such as Save The Bay, the Sierra Club, or the Audubon Society, among
several others, have been extremely vocal in environmental advocacy, and have often
actively opposed development of salt ponds or landfill around the Bay (Walker 2009).
They also have a role in keeping the pressure on legislators and regulators to enforce
environmental protection standards.
Both developers and environmental NGOs are able to resort to tools often not at the
disposal of public agencies, such as extensive public outreach through mass mails,
political lobbying, or the creation of media campaigns. While in other parts of the
country the balance may have tipped well to the side of private development interests,
in the Bay these legal battles have often been decided in favor of habitat protection
and restoration, and public agencies active in the region will likely take comfort in
having a lot of public support for their activity.
4.5 Conclusions
While broad mitigation/adaptation strategies are decided at the National or State
levels, the actual implementation of SLR adaptation measures often require a great
deal of involvement of local actors. Given that it is at this juncture that adaptation
takes a concrete spatial expression, this is also the moment when land-use conflicts
arise. Local governments are left with much of the burden of mediating competing
interests, between urban development, environmental protection, and other social
107
demands. In some instances, the prospect of shoreline development may be very
attractive for both property owners/developers and local governments, given the
potential land value and economic benefits, but these have to be weighed against the
medium-/long-term costs of defending these assets from rising sea-levels.
In San Francisco Bay, there is an increasing awareness of the challenges posed by SLR,
but the institutional arrangements are complex, and communication between the
different public agencies/departments is not always as streamlined as it could be.
Some agencies and departments need to adapt their procedures in order to remove
institutional barriers to adaptation, but path dependence is an obstacle. The several
projects where different federal and state agencies are partnered with local
governments highlight the benefits of a more frank and regular communication
between public actors. It also emphasizes the benefits of a coordination of efforts and
strategies, something that was eroded in the transition from government-led policies
to a new paradigm of local-based adaptive governance.
While the articulation of public actors is often easy to address by increasing
communication and coordination, conflicts involving private landowners and
developers may be much complicated by the threat of litigation. The lack of a strong
legal backing to public environmental protection mandates is a major obstacle to
shoreline planning around the Bay and elsewhere, and this is highlighted by the
extreme caution of some public agencies in upholding their jurisdictions over private
property.
Environmental NGOs have, in the case of California, a big role to play, as they are able
to resort to the same legal and lobbying instruments as the developers, and may help
even-out the field between public stakeholders with limited legal and economic
resources, and powerful private developers with nothing to lose. There is seemingly a
sense of urgency in pushing for the development of shorefront properties, as public
opposition to development on locations exposed to SLR is most likely to increase in
the coming decades. At the same time, NGOs and public agencies are aware of the
stress wetlands will be under as the rates of SLR increase towards the end of the
century.
“Green”, or ecosystem-based, adaptation is already on the way around the Bay. Large
scale wetland restoration projects have already been concluded, and further action
now often requires articulation with the reinforcement of flood defense structures,
given the level of urban encroachment. While levee setback, or removal, would
provide greater environmental benefit, the need to protect urban areas and
infrastructure has led to the trial of ingenious solutions for promoting wetland
resilience while upgrading the level of protection granted by levees.
108
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APPENDIX A – SEA-LEVEL RISE MAPPING FOR THE SAN FRANCISCO
BAY
116
Figure A. 1 – Current situation at ~0 m (MSL) (Brown: urban development over former
wetlands)
117
Figure A. 2 – +1 m above current MSL (Blue: Wetlands below water level; Red: Artificial
(urban) areas below water level; Yellow: Non-artificial areas below water level)
118
Figure A. 3 – +2 m above current MSL (Blue: Wetlands below water level; Red: Artificial
(urban) areas below water level; Yellow: Non-artificial areas below water level)
119
Figure A. 4 – +3 m above current MSL (Blue: Wetlands below water level; Red: Artificial
(urban) areas below water level; Yellow: Non-artificial areas below water level)
120
Figure A. 5 – +5 m above current MSL (Blue: Wetlands below water level; Red: Artificial
(urban) areas below water level; Yellow: Non-artificial areas below water level)
121
Figure A. 6 – +10 m above current MSL (Blue: Wetlands below water level; Red:
Artificial (urban) areas below water level; Yellow: Non-artificial areas below water
level)
122
Figure A. 7 – +25 m above current MSL (Blue: Wetlands below water level; Red:
Artificial (urban) areas below water level; Yellow: Non-artificial areas below water
level)
123
APPENDIX B – SEA-LEVEL RISE MAPPING FOR THE TAGUS ESTUARY
124
Figure B. 1 – Current situation at ~0 m (MSL) (Brown: urban development over former
wetlands).
Figure B. 2 – +1 m above current MSL (Blue: Wetlands below water level; Red: Artificial
areas below water level; Yellow: Non-artificial areas below water level)
125
Figure B. 3 – +2 m above current MSL (Blue: Wetlands below water level; Red: Artificial
areas below water level; Yellow: Non-artificial areas below water level)
Figure B. 4 – +3 m above current MSL (Blue: Wetlands below water level; Red: Artificial
areas below water level; Yellow: Non-artificial areas below water level)
126
Figure B. 5 – +5 m above current MSL (Blue: Wetlands below water level; Red: Artificial
areas below water level; Yellow: Non-artificial areas below water level)
Figure B. 6 – +10 m above current MSL (Blue: Wetlands below water level; Red:
Artificial areas below water level; Yellow: Non-artificial areas below water level)
127
Figure B. 7 – +25 m above current MSL (Blue: Wetlands below water level; Red:
Artificial areas below water level; Yellow: Non-artificial areas below water level)
128
APPENDIX C – COMPARISON OF AREAS RENDERED BELOW SLR IN
SAN FRANCISCO BAY AND TAGUS ESTUARY
129
Land Use Class
Urban Fabric
Other artificial areas
Farmed or grazed land
Forest
Grass, shrub or scrub
Barren land
Salt and regulated ponds
Natural wetlands
Wetlands (marshes)
Wetlands (mudflats)
Total under sea-level
Permanently flooded
0
0
173
0
0
0
94
760
1.440
2.200
9.771
14.439
101.775
San Francisco Bay - Elevation above current Mean Sea Level (m)
1
2
3
5
10
15
20
88
1.354
4.174 13.630 37.062 56.664 71.740
1.632
6.772 10.821 15.069 18.193 18.537 18.628
2.816
9.952 12.499 13.706 15.213 16.747 18.508
3
5
10
51
106
199
293
18
348
1.487
4.107
8.474 12.152 14.790
859
2.398
3.514
4.056
4.538
4.648
4.709
11.986 17.161 21.550 23.584 23.851 23.862 23.866
25.353 32.999 35.154 35.947 36.376 36.474 36.554
37.339 50.160 56.704 59.531 60.228 60.336 60.420
11.200 11.582 11.698 11.755 11.793 11.796 11.796
91.293 132.730 157.611 181.436 215.835 241.415 261.303
102.319 103.022 103.229 103.685 103.767 103.979 104.060
25
83.923
18.684
20.428
434
17.354
4.809
23.868
36.576
60.445
11.797
278.319
104.089
Table C. 1 – Land area of each classof land use rendered below each step of SLR above
current MSL (in hectares) – San Francisco Bay
Tagus Estuary - Elevation above current Mean Sea Level (m)
0
1
2
3
5
10
15
20
Land Use Class
Urban Fabric
0
166
555
881
1.745
4.436
7.525 10.321
Other artificial areas
0
31
120
178
266
578
949
1.284
Farmed or grazed land
0
4.991 19.804 27.453 37.813 51.846 68.906 82.523
Forest
0
5
123
326
919
2.996
6.117 10.379
Grass, shrub or scrub
0
53
494
892
1.730
3.628
5.930
8.636
Barren land
0
84
183
213
266
541
902
1.090
Wetlands (marshes)
0
1.194
3.289
3.784
3.997
4.109
4.340
4.439
Wetlands (mudflats) 15.280 15.280 15.280 15.280 15.280 15.280 15.280 15.280
Total under sea-level 15.280 21.805 39.848 49.006 62.016 83.413 109.949 133.952
Permanently flooded 29.792 29.792 31.460 31.782 32.374 32.963 33.778 34.232
25
12.608
1.550
93.974
15.455
11.627
1.232
4.455
15.280
156.182
34.526
Table C. 2 – Land area of each classof land use rendered below each step of SLR above
current MSL (in hectares) – Tagus Estuary
130