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LA River Studio | Book

2002, LA River Studio | Book

Designing this section of the Los Angeles River is a big project. As the studio studied the site and developed proposals, the scale and the importance of the undertaking continued to be underscored. Changing the physical character of the Los Angeles River is an extreme task, but it is possible. The transformation of this space could be considered iconic of a new era for Los Angeles. The Harvard Graduate School of Design Master of Landscape Architecture students have shown that this section of the Los Angeles River is ripe for creative and imaginative proposals that bring the river back to the city and the neighborhoods as a valuable resource. The river can become important to the people who live near it and those within the region—it can be a newfound icon. This project is big. It is important. It is ready for the next imaginative step.

LA river studio |b o o k Students Brad Cantrell Annie Gilson Anna Kaufmann Han Song Lee Chih-Wei Lin Jie Liqiu Wes Michaels Alissa Puhm North Ryosuke Shimoda James Smith Todd Wenskoski Chung-Hsun Wu harvard university graduate school of design department of landscape architecture LA River Studio Book Professor George Hargreaves LA river studio |b o o k harvard university graduate school of design department of landscape architecture LA river studio |b o o k harvard university graduate school of design department of landscape architecture Editor George Hargreaves Chairman of the Department of Landscape Architecture Harvard Graduate School of Design Student Editors Annie Gilson MLA '02 Alissa Puhm MLA '03 Students Brad Cantrell Annie Gilson Anna Kaufmann Han Song Lee Chih-Wei Lin Jie Liqiu Wes Michaels Alissa Puhm Ryosuke Shimoda James Smith Todd Wenskoski Chung-Hsun Wu Project Advisors Kathleen Bullard, MRCA Mia Lehrer, Mia Lehrer & Associates Lewis MacAdams, Friends of the Los Angeles River Copyright © 2002 President and Fellows of Harvard College All rights reserved. No part of this publication may be reproduced without permission. The work herein is that of individual authors; it does not necessarily represent the views of the Graduate School of Design, Harvard University, or any of its programs or faculty. ISBN 0-935617-57-4 Published by Harvard University Graduate School of Design Printed in the United States of America Copies of LA Studio River Book are available for purchase from: Harvard University Graduate School of Design Book Orders 48 Quincy Street Cambridge, MA 02138 617.495.4115 Mountains Recreation and Conservation Authority LA River Center & Gardens 570 West Avenue 26 Suite 100 Los Angeles, CA 90065 323.221.8900 The Harvard Design School is a leading center for education, information and technical expertise on the built environment. Its departments of Architecture, Landscape Architecture, and Urban Planning and Design offer masters and doctoral degree programs and also provide the foundation for its Advanced Studies Programs and Executive Education. LA river studio |b o o k harvard university graduate school of design department of landscape architecture contents 1 7 |introduction friends of the los angeles river lewis macadams santa monica mountains conservancy kathleen bullard mia lehrer + associates mia lehrer urban partners dan rosenfeld harvard university graduate school of design department of landscape architecture george hargreaves 2 9 |student projects strategy alissa puhm | ryosuke shimoda | han song lee habitat annie gilson | chung-hsun wu water cleansing james smith | chih-wei lin recreation anna kaufmann | jie liqiu edge todd wenskoski | brad cantrell | wes michaels 9 9 |groundwork los angeles river history landuse analysis maps hydraulics information precedents 1 5 5 |epilogue los angeles river studio book 9 introduction 1 8 |friends of the los angeles river lewis macadams 2 0 |santa monica mountains conservancy kathleen bullard 2 2 |mia lehrer + associates mia lehrer 2 4 |urban partners dan rosenfeld 2 6 |harvard university graduate school of design department of landscape architecture george hargreaves Proposal When landscape architect Mia Lehrer first approached me with the possibility that Friends of the Los Angeles River could work with the Harvard Graduate School of Design's ‘Sponsored Studio,’ I was thrilled; and immediately suggested that they take on the most intractably industrialized, most inaccessible, most degraded part of the Los Angeles River in the city of LA, the River through downtown. Cut off by factories, warehouses, junkyards, and railroad tracks running along both sides, its banks and bed encased in concrete, this four mile stretch of river paradoxically offers the 250,000 people living in Lincoln Heights and Boyle Heights, and the 300,000 who work and increasingly live downtown, a tremendous opportunity to create parks, schools, housing, and jobs, raise property values and build stronger and healthier communities in the heart of the city. The proposals you see here are the results of one of the most extensive research projects yet undertaken along the Los Angeles River. In September of 2001, 12 graduate students under the direction of George Hargreaves, the chairman of the Harvard Graduate School of Design's Landscape Architecture Department, spent three days in Los Angeles where they received a series of intensive briefings on a dizzying array of relevant topics from the history, politics and demographics of the riverfront communities to the economics of redevelopment, the mechanics of flood control, and the river's flora and fauna. The class met with everyone from the LA County Department of Public Work's Watershed Management Division and the U.S. Army Corps of Engineers to the tenant's association at Pico-Aliso Village, the vast public housing project east of the river. In the clearest possible underlining of the dimensions of the problems they had taken on, the students were almost arrested for trespassing in the Union Pacific's Los Angeles Transportation Center, an active railyard that takes up almost a mile of riverfront directly across from downtown, and emerged as the pivitol property in many of these plans. Lewis MacAdams Chairman of the Board of Directors Friends of the Los Angeles River lewis macadams 18 After their site visit, the Harvard students went back and began to draw. Their preliminary work was reviewed three times over the course of the semester by representatives from the Mountains Recreation and Conservation Authority, the Corps of Engineers, the offices of County Supervisor Gloria Molina and City Councilman Ed Reyes, Northeast Trees, the Latino Urban Forum, and Friends of the Los Angeles River. The results of the study were first presented in LA during February of 2002. Many people contributed to the success of this project. In particular, I would like to thank Mia Lehrer of Mia Lehrer & Associates who oversaw this whole effort; Joe Edmiston of the Santa Monica Mountains Conservancy, who agreed to fund the project; and Kathleen Bullard and Belinda Faustinos of the MRCA, who figured out how to pay for it. Both Kathleen and Cara McLane of the MRCA brought their own skills as landscape architects to the project, as did Lynne Dwyer. Dan Rosenfeld of Urban Partners and Alex Ward, the Design Director of the architectural firm of Leo A. Daley, helped bring a business perspective to what might have been an ivory tower exercise. Architect Arthur Golding added his vast knowledge of planning and design issues in this part of the city. Doug Suisman of Suisman Urban Design supplied historical context. Stephen Callis, whose brilliant photos have brought this stretch of the river into the public eye for the first time; artist Lane Barden, whose visionary efforts to create a lake in the downtown river channel influenced a number of these projects; Poet and cultural analyst Ruben Martinez, James Rojas of the Latino Urban Forum and the Metropolitan Transportation Authority; Katie Klapper, Chi Mui, and David Diaz, Board members of Friends of the Los Angeles River, Andy Lipkis of Tree People, Robert Garcia from Center For Law in the Public Interest, Los Angeles City Councilman Ed Reyes and his deputy Alan Gee; City Council member Jan Perry and her planning deputy, Darryl Sweeney, County Supervisor Gloria Molina, and her planning deputy, Carrie Sutkin; and State Assemblywoman Jackie Goldberg and her deputy, George Magellanes, all helped make this possible. Above all, I would like to thank George Hargreaves. His pioneering work in restoring riverfronts across the United States has established principles and provided examples that all of us in LA need to consider as we begin the effort to transform the River through downtown from an object of pity and contempt and an example of every mistake humankind has ever made in our long history of living alongside rivers, into a symbol of hope and a source of beauty, inspiration, and sustenance. introduction 19 Parameters The Harvard Graduate School of Design students created a provocative vision of the Los Angeles River that challenges the viewer to imagine a dreamscape of beaches, new ecologies, and connections across the city. The task now is to build upon these proposals by taking the best from them, re-sorting them, and bringing forth a set of workable projects that transform this section of the Los Angeles River and its environs. The students' analyses make clear the challenges facing this stretch of the river and the communities surrounding it. One cannot view the work from the confluence of the Arroyo Seco and Los Angeles River to the Los Angeles City border with Vernon as the creation a single project in need of massive funding and political will. Implementation and change will occur, as it always does, in fits and starts. From the initial mini-park on a residential lot to the creation now of multi-acre riverfront parks, a strong constituency has been built for re-greening the river. Yet this constituency is made of various organizations, alliances, and individuals who may not have a shared image of how this will be manifested in the environment. Disagreements exist over active versus passive recreation, the primary targeted user groups, access, and habitat restoration, to name a few. The ultimate outcome of the redesigned city and river will be wrought through the often messy, but effective, process of public planning. The greater question becomes not what do we implement, but how? Do we have the existing resources in place to affect a change of this magnitude over time? Kathleen Bullard Chief of River Projects Mountains Recreation and Conservation Authority kathleen bullard 20 The Santa Monica Mountains Conservancy and sister agency, the Mountains Recreation and Conservation Authority built the first mini-park in Elysian Valley in 1996 that offered a glimpse of a new attitude towards the river. While the bank of the river may be concrete, where the riverbed is naturalized, opportunities exist for bird watching, enjoying the sound of water as it passes over the rocks, and connecting with nature in even a small way. It created a place for people to see the river, albeit through an opening in the fence (newer parks are now open to the river). Los Angeles County park bonds passed in 1992 and 1996 initially paid for this park and subsequent ones. In March 2000, state-wide park and watershed bonds were passed for the first time in 17 years for a total of $4 billion. Again in March 2002 voters passed park bonds totaling $2.6 billion. Funds were slated specifically for river parkways (which unlike elsewhere in the country do not refer to roads) as part of the legislation. The possibility for parks in every city along the river is beginning to be realized. However, rather than simply fix up the edges, a desire for dramatic change, one that creates a new urban ecology with habitat for endangered species such as the steelhead trout, recreation for people, and improved water quality exists at the edge of our consciousness. After the devastating floods of 1934 and 1938, the Army Corps of Engineers were given the task to "fix the river" and save Los Angeles from flood. Using the best available technology, and approximately $5 billion in today's dollars, the Corps fulfilled its mission perfectly. But at what a cost! The river is lined with some of the poorest communities most in need of open space, brownfields lie adjacent to its banks, and habitat is all but lost. The Los Angeles County Department of Public Works estimates that in 20 years the flood control infrastructure will be obsolete. The Los Angeles River will never be restored to its natural state, when it moved wildly across the Los Angeles plain changing course and displacing the 6 million people who live there. Now is the time to start planning its replacement, but with a new mandate - bring back the habitat, clean the water, and make it a natural amenity, while maintaining flood protection. It can be done. Just as the Los Angeles River flood control channel was at the leading edge of technology in its day, so it should be again. With the will of the people firmly behind it already, a partnership at every level of government and the dollars to back it up - should re-create the Los Angeles River and transform it from today's poor joke into the centerpiece of a great city. The Harvard Graduate School of Design studio work begins to show us the way. introduction 21 Perspective Los Angeles is a stunning canvas for the landscape architect. Its history is, among other things, one of squandered opportunity in the making of vast infrastructure. No place is this more evident than in the evolution-some might say, devolution-of the Los Angeles River. As a member of the Graduate School of Design Alumni Council, I became familiar with, and intrigued by, the "Sponsored Studio" projects, now an integral part of the Studio offerings at School. The resonant possibilities for students, faculty, alumni, and communities involved in these projects were compelling. The work I saw being produced was powerful and often inspired. The depth of the curriculum in the Department today-from Brownfield reclamation to watershed management to the creation of beautiful places-suggested that a Sponsored Studio focusing on the Los Angeles River could be a triggering mechanism for complex change that only an expansive landscape architectural approach could provide. Realizing this, I called my colleague and fellow classmate, George Hargeaves, and suggested this Studio. Contacting Joe Edmiston, Director of the Santa Monica Mountains Conservancy, resulted in their sponsorship of the Studio. I asked my friend, Lewis MacAdams, the driving force of the Friends of the Los Angeles River, to give voice to this endeavor. Mia Lehrer, ASLA Harvard Graduate School of Design, MLA ‘79 Mia Lehrer + Associates mia lehrer 22 introduction 23 Possibility The river is the most important real estate in Los Angeles. From the beginning of human settlement, it has defined how, why and where our city exists. Early European settlers discovered a valley resembling paradise on earth. The river they named Los Angeles flowed from snowcapped mountains into the largest arable plain on the west coast of the continent. Starting in the early years of the Pueblo, the topography of the river and its watershed have defined the morphology of our community. Even when imported water and accelerated transportation systems unleashed patterns of oncological growth, the river remained the fundamental natural spine of the city. Through years of mistreatment and abuse, the river has exerted an inescapable influence on patterns of human activity in the Los Angeles basin. In a metropolis so large that it is best viewed from satellite photos, the original organic configuration of the land is still visible. The river is still there. A small, grass roots organization called the Friends of the Los Angeles River, and its founder Lewis MacAdams in particular, have inspired a dramatic change in the last two years, demonstrating the significance and, even more important, the immense potential of the Los Angeles River. The river is now, without question, the most important land use opportunity in North America's third largest city (we do not forget Mexico). This potential exists in multiple dimensions: The environmental benefits of the river are beginning to be seriously studied: the potential to improve groundwater balances, soil and air chemistry and the health of our entire ecosystem on land and far out to sea. Environmental impacts run deep into the web of human occupancy. For example, higher density mixed-use development along the river will profoundly address our second most significant land use challenge transportation and also benefit our notorious struggles for air quality and the preservation of the mountains and beaches that surround the urbanized core. Dan Rosenfeld Principal Urban Partners dan rosenfeld 24 Economic benefits are also underappreciated. Ironically, the greatest beneficiary of a revitalized river may well be the City's famous real estate devel- opment "machine." Once committed to sprawl on a mega-urban scale, the real estate industry will soon discover that a 58 mile river, appropriately enhanced, yields 116 miles of new waterfront, an invaluable commodity that is traditionally assumed to be in finite supply. Other cities demonstrate the retail, recreational, residential and mixed-use development potential that riverfront or lakefront real estate allow. Small trickles in San Antonio, new lakes in Phoenix and reemerging waterfronts in San Diego and San Francisco show that high quality and successful waterfront redevelopment do not require a Hudson or a Charles. The land value appreciation created by this new waterfront development, which could be 500% or more, say from $15 to $100 per square foot, if captured in property taxes, will finance the acquisition and improvement of the land itself. In this sense, the riverfront is "self-financing," a major public works project that can pay for itself. Beyond specific development opportunities on the banks of the river, are the larger, macroeconomic benefits that a centralized community can provide. There is no question that dense, centripetal cities are more efficient, that they use basic factors of economic production such as land, energy and time more efficiently and therefore compete more successfully on a global scale. Economic success, in turn, funds social welfare, culture and quality of life. But perhaps most valuable in our time and place are the social and political benefits that the river can impart. By drawing people back together, as well as back to our historical and natural roots in the land, the river will create the sense of community, of civitas in the traditional Latin sense, so urgently required in a community as diverse and dispersed as Los Angeles. It is no exaggeration to propose that the Los Angeles River alone can reverse the fundamental trend of urban growth in Southern California, from centrifugal sprawl to a renewed focus on the center, in both physical and psychological terms. In that context, we may someday see the evolution of our City as a single cycle: to the river, then away from it, and then back again. introduction 25 Project Strategy Habitat Water Cleansing Recreation Edge The purpose of a design studio at Harvard is to provide a fulcrum for critical inquiry into specific sites. Often, as in the Los Angeles River Studio, students are asked to develop a program of land use and define its characteristics as an articulated physical proposal. Since this was an advanced studio there was neither an agenda nor an overarching set of objectives provided. Each student was asked to perform independent design research based on a conceptual exploration of the entire four mile long site. The teaching approach was at times one of encouragement and at others one of challenging, questioning, or probing. The methodology of the studio began with a series of analyses performed in groups of two: watershed hydrology, regional and adjacent land uses, national and international precedents, engineering principles of flood control, water remediation techniques, and an architectural inventory of significant structures were topics identified by the studio. The class then spent three days in Los Angeles touring and photographing the site, meeting with local stakeholders, and having extensive conversations with the studio sponsors and the Army Corps of Engineers. Two broad assumptions emerged from these meetings: one, that the railroad tracks on the east side could be considered removable whereas the tracks on the west side were not and, two, that to completely replace the concrete channel would require a widening of the river corridor of up to 6 or 7 times. George Hargreaves Chaiman of the Department of Landscape Architecture Harvard Graduate School of Design george hargreaves 26 The student work as presented here coalesces around five themes: strategy, habitat, water cleansing, recreation, and edge manipulation. These themes represent the central concerns revealed in the student work rather than a grand systemic vision. In introducing each theme some definition seems in order. Strategies involve a significant set of operations that occur over a long period of time; often the final outcome is not as much of a concern as are the means employed to get there. Habitat refers to those projects that provide large scale wildlife areas within their projects. The water cleansing or remediation projects seek to create a landscape that cleans pollutants from surface water run-off before returning it to the hydrologic cycle. Recreation forms the central theme of those projects that prioritize neighborhood enhancement. Finally, the edge projects are those that realized that edge is the key to opening up the river to the city and resolving flood control issues at the same time. Although one can certainly find other thematic elements within each project, we found central themes served to demystify a large complex site and the individual conceptual approaches. Upon our return to Harvard the students began their individual work. The studio sponsors, stakeholders, and political representatives of the district attended two preliminary reviews and one final review at Harvard. In January 2002 the studio returned to Los Angeles to share their work with the general public and stakeholders. The entire studio lasted fourteen weeks. introduction 27 student projects 3 0 |strategy alissa puhm ryosuke shimoda han song lee 5 0 |habitat annie gilson chung-hsun wu 6 0 |water cleansing james smith chih-wei lin 7 0 |recreation anna kaufmann jie liqiu 8 0 |edge todd wenskoski brad cantrell wes michaels River System Los Angeles spends one billion dollars a year to import water, while every day 100 million gallons of water flows down a concrete channel, otherwise known as the Los Angeles River. This project attempts to deal with water at the source, at the level of the watershed, and use it as a resource. Implementation of best management practices at the watershed scale are suggested, such as cisterns to collect water to use on site, residential scale retention systems, property detention grading, the use of drought tolerant planting, and the implementation of low flow plumbing. These practices would be phased in incrementally, with emphasis placed in high flood risk areas. The watershed strategy aims to increase the productivity of the watershed. At the site scale this project attempts to use the channel as an existing infrastructure resource with slight modifications. Incisions take place in the channel walls trapping sediment and debris, setting a base for incidental vegetation to grow. The cuts are the first transformative step and become the symbol for the beginnings of a park, which will occur at bank level. With this strategy, the channel crumbles, slowly allowing the transition to become ingrained in the attitudes of its users, rather than the channel being there one day and missing the next. The parks serve as appendages to the concrete channel system, allowing the channel to function as a river system. Each park is initially structured by revealing its past uses and by making new connections to the surrounding neighborhoods, while directing it toward a potential wetland condition determined by its location in the watershed and how flood water can enter the site. The sites are set with an initial planting, but attempt to reverse the 'fallacy of green' by allowing evolution, which is directly related to the quantity of water that may flow into the site over time. Although we recognize our impact on the environment, it is critical that we take steps to work with systems intelligently in a manner that allows them to evolve rather than exist statically. This project attempts to achieve that through maximizing function with minimal intervention. alissa puhm 30 strategy 31 alissa puhm 32 strategy 33 alissa puhm 34 strategy 35 alissa puhm 36 strategy 37 alissa puhm 38 strategy 39 Proposed Field Protocols My proposal is not to remove the industrial area and to simply situate new parks, but rather to change the huge industrial space into a zone of environmental industry that would concurrently produce new nursery stock and remediate the soil. Local residents will be able to benefit from these environmental changes. The plants grown here and the resulting healthy soil will be distributed throughout the new riverside recreation and residential areas. This proposal will take approximately thirty years to complete and has the following three phases. North Park Phase 1 2005 - 2010 Phytoremediation on the Existing Rail Yard Nurseries will be set up on all vacant lots that are located within two to three blocks of this section of the river. These nurseries will produce plants that will also clean the soil through phytoremediation. Phytoremediation will also take place on the existing rail yard site. As the plants grow at the nurseries, they will be used to vegetate interstitial spaces that can be used for recreation. West Residential Area and SCIArc Rail Yard Phase 1 Phytoremediation on the Rail Yard Phase 2 2010 - 2020 Remediation Completion and Start of Production During this phase, phytoremediation of the rail yard will conclude. The rail yard site will begin to function as a nursery. At this point the spatial structure of the rail yard will also change. Phase 2 Phytoremediation and Production (Nursery) Phase 3 2020 - 2030 Coexistence of Productive Space and Landscape Along the river, most of the manufactured sites will be transformed into places where functioning nurseries and recreational areas coexist. Phase 3 Production and Recreation ryosuke shimoda 40 strategy 41 South Park Land Use Phasing Existing Condition Phase 2 2010-2020 Phase 1 2005-2010 Phase 3 2020-2030 ryosuke shimoda 42 strategy 43 Territory Assemblage This section of the Los Angeles River is surrounded by industrial manufacturing buildings that have the potential to be redeveloped into an information technology and service-based district. Such dynamic changes are already underway in this area. Railroads along the river will be moved outside of this downtown area, and many warehouse structures and factories will be either transformed for new uses or eliminated. Ecologically friendly flood control measures will replace the current concrete channel. Historically, parks have provided both natural habitats and places of recreation for people. This project envisions a different kind of park, one with a flexible quality that will accommodate the complex dynamics of the site. A new park will promote the redevelopment of the largely abandoned district and provide complex and diverse urban activities and cultural programs for the use of the community. The Los Angeles Riverfront Park will be a regional park due to its large scale and the impetus it will provide for further redevelopment within the area. The park will provide regional attractions such as beaches and natural resources, which will play a major cultural role at the regional scale. han song lee 44 strategy 45 Phase 1 Phase 2 Strengthen the Existing Community, Artist Studios, Institutions, and Community Parks Change the Territory, Rail Yard Area Development han song lee 46 Land Use Land Use Infrastructure Infrastructure Access Access Structure Structure strategy 47 Phase 3 Phase 4 Evolve to Regional Attraction, Loft House Park Development Long Term Potential Detention Land Use Retention Infrastructure Access Structure han song lee 48 strategy 49 Breaking the Channel With regular maintenance of channel debris and the establishment of an effective warning system for the public, the river, or rather the massive concrete void that the river only periodically fills, could actually be occupied. The sparks of spirit that appear within the culvert come from life finding small moments of potential sustenance. Imagine possibilitiesstretching small cracks in the concrete into more substantial breaks, until whole portions of the wall come down and reveal new permeable edges that could re-supply the aquifer below. Pedestrians and bicyclists, even horseback riders, could use the channel as a recreational path, safe from the traffic above. An existing ramp beneath the Seventh Street Bridge, one that reaches from street level on the west side of the rail yard down into the riverbed, suggests a promising way to invite pedestrians into the channel. A ramp would not only provide universal access from the old industrial neighborhood into the riverbed, but it would also act as an effective transition zone for flood overflow. This ramp, along with the existing rail yards and electrical towers, could be an urban backdrop to an entertainment plaza offering indoor and outdoor movie screenings, restaurants, music stores and galleries. On the other side of the river, between the Hollywood and Santa Monica Freeways, floodwaters could periodically break out of the aqueduct and infiltrate a large public park graded to accept, absorb and then release storm flow back into the channel a mile downstream. This botanical park would especially benefit the neighborhoods to the east of the river, those families underserved by a lack of nearby open space. The wide corridor would provide habitat to migratory birds and planted native vegetation, serving an environmental purpose similar to the ecologically rich banks of the early Los Angeles River. The Los Angeles River can become a destination where the individual might safely measure his scale against the scale of a flood. Marking this experience could be encouraged; the authorities could allow spray painting. Here, a new ecology can evolve, one that both embraces the safety provided by past responses to drought and flood, but one that also warps seemingly rigid restrictions into opportunities for inhabitance. annie gilson 50 habitat 51 annie gilson 52 habitat 53 annie gilson 54 habitat 55 Ecology for Birds The Los Angeles River is an important flood control channel. In addition, this concrete basin has become one of its city's icons. Although its purpose as a flood control channel is essential, the river itself is now considered a negative place. Its most serious drawback is that it serves almost no ecological function. Finding a way to naturalize the river is now a priority. This project proposes to fulfill this need, not by creating a natural form, or removing the concrete base, but by creating a functioning river to support human society and ecological integrity. linkages bird movement chung-hsun wu 56 habitat 57 patches proposed flood condition prominent spots current flood condition river energy current river condition Currently, the non-concrete portions of the river and reservoirs at the upper reaches of the river, such as the habitat north of Elysian Park, show the ability to support birds and wildlife. In an attempt to introduce and maintain biodiversity closer to downtown Los Angeles, this project intends to create bird habitats - stepping-stone patches and corridors for the movement of birds. In support of this plan, abundant bodies of water and zones of vegetation need to be created. Capturing water can be accomplished by raising the water level in two areas bounded by inflatable dams. In this way humans and birds can coexist within an urban context. The artificial river will be given new meaning and an increased ecological function. long lines proposed water condition isolation Bird Habitat 1 Bird Habitat 2 Bird Habitat 3 Master Plan chung-hsun wu 58 habitat 59 Plug In River Parks There are three major elements in this design approach to the Los Angeles River: 1. The Union Pacific Rail Yard Water View Park An amenity driven park designed to maximize the use of a large space. The expanse of water and beach enclosed by natural vegetation provides a unique sublime experience easily accessible by the surrounding community. The inclusion of recreational program and residential property further improves the usability of the site. The park is system based and powered by a water cleansing process. 2. The Plug In Neighborhood Park These smaller parks are inserted into the existing fabric of the community, creating a new device for ordering the development of the neighborhood. The edges of these parks become energized and can develop into strong residential and commercial communities. The parks are designed to use water-processing technologies to both drive the landscape and illustrate human participation in this system. The amenities of open lawn space and water edges will become places for occupation and enjoyment within the community. The Plug In Parks can also serve as green centers and environmental filters for industrial districts. The installation of a Plug In Park is a process that considers economic, community, residential, and commercial variables in determining the scale of a site. The cooperative development and construction processes will determine the eventual physical details of one of these spaces. 3. Campus or Institutional Bridging This is an opportunity to bridge the gap created by the river. In this case the grounds of SCIArc are extended. An efficient bridging system is built which spans the river channel and connects to recreational program on the other side. The bridge itself contains commercial program and becomes an armature of the area's new pedestrian community. james smith 60 water cleansing 61 Use water-powered systems to illustrate the human relationship to the constructed ecology of Los Angeles Establish or strengthen neighborhood communities through the insertion of new spaces and edges Design adaptable prototype park spaces that use a number of functional variables to ultimately build a Plug-In Park Establish connection perpendicular to the LA River Bridge the Gap Come down to the Water Create mixed pedestrain, bicycle, and vehicular link on existing roads parallel to the river channel linking park spaces Maximize potential of newly available spaces to create large landscape experiences where possible james smith 62 water cleansing 63 james smith 64 water cleansing 65 Branches The 'branches' strategy includes both parkway and hydrologic networks reaching through the neighborhoods adjacent to the Los Angeles River. This approach focuses on breaking the boundary of the current Los Angeles River and allowing its fabric to expand and fit into the urban context. Proposed Housing Union Pacific Rail Yard In the first phase, the twenty-five year flood control measures are kept in some areas of the concrete channel, while the material of other areas are changed to be permeable. The second phase focuses on regional housing redevelopment and the initiation of the branch systems at areas of critical conjunction along river. In order to break the isolation of the river, caused by railways and industrial land use, this project proposes removing the rail lines and reconstructing abandoned warehouses into public loft studio housing, supporting both commercial and mixed-use housing programs. Also in this phase, the branch systems would extend several riverbank areas into the neighborhoods. Sports Park Residential Branches These branches would serve to combine pedestrian, bikeway, and green ditches, thereby offering strong neighborhood-scale parkway channels by which local residents could trace their way to the Los Angeles River. The branch system would play a role in recharging the underground water system and remediating contaminations in the soil through phytoremediation. By implementing 'branches', planners could open the Los Angeles River to the public, a move that would offer environmental and health benefits to the entire city. SCIArc Yard Proposed Railway Branches Under Bridge Flooding stages LA Cultural Park Commercial Branches Unaccessible Areas Fragmented Space Commercial Potential chih-wei lin 66 Connecting Branches water cleansing 67 Entrance to Union Pacific Rail Yard Union Pacific Rail Yard Residential Area Branches SCIArc Yard Branches Under Bridge chih-wei lin 68 water cleansing 69 Connections Park Space Water Quality The project is driven by three goals: 1. to make connections across the channel 2. to provide park space and river access for the residents of East Los Angeles 3. to improve the quality of the river water Currently the river channel functions as a barrier between East Los Angeles and the downtown area. The channel also prevents people from accessing the river. The project strategy alternately pulls back the river channel to create park zones and pinches the river channel to create urban connections. The union pacific rail yard has been transformed into a constructed wetland that will cleanse the river water, protecting park goers to the south and ultimately sending cleaner water to the ocean. The constructed wetland also provides significant wildlife habitat. The project has a north-south spine developed along existing roads. Major urban connections are pulled off the spine across the channel. The language of the urban context is pulled from the spine into the park zones in the form of terraces, piers, and groves that serve as landscape rooms. cut in channel wall constructed treatment wetland connections institutional anchor pores treated water returns to channel community gardens proposed pico aliso development pedestrian connection urban promenade and boardwalk park zones Water is diverted from the channel into the constructed wetland located in the Union Pacific Rail Yard site. The existing channel wall is maintained along this stretch to protect the fragile wetland from floods. South of the rail yard the channel wall is alternatively pulled back and built in to create park zones and connections. amphitheater pedestrian connection marketplace water pedestrian connection over rail sports zone citrus grove strategy anna kaufmann 70 return of water to main channel recreation 71 anna kaufmann 72 Constructed Wetland and Institution Citrus Grove and Sports Zone Terraced Pathways and Piers Amphitheater and Reflecting Pool recreation 73 Section Looking East Union Pacific Yard Constructed Wetland and Institution Section Looking South Sports Zone and Citrus Grove anna kaufmann 74 recreation 75 Transition The Los Angeles River is inaccessible and hidden by industry. Undoubtedly, the people of Los Angeles need a renewed open space. Overflow Linkages Neighborhood Park Water Levels Connections Following the topography, the study area is divided into four levels in order to address conditions caused by varying water levels. The riverbed is widened to handle larger flood volumes. Vegetation is used to link access around the park and to connect the east and west sides of the river. Urban areas transition to natural landscapes. The trees planted in west bank of the river become a green wall to screen noise and the chaotic influence of the railway. These parks have the potential to bring serene places of relaxation into the frantic urbanity of Los Angeles. Regional Park The Los Angeles River has had continuous flooding problems. This project attempts to solve flood control issues and provide much needed open space in the area adjacent to downtown Los Angeles. jie liqiu 76 recreation 77 jie liqiu 78 recreation 79 Framework+Strategy The Los Angeles River is a neglected river. It has a single function, to remove water from Los Angeles with expedience and safety. This single view neglects the ecological environment, the city, and most of all the residents of Los Angeles. The history of the Los Angeles River goes beyond the simple metaphor of water. The Los Angeles River represents a territory defined by natural, political, economic, and cultural forces. Only through the convergence of these additional metaphors can the river begin its new trajectory. This project recognizes the convergence of forces and establishes three influences as its conceptual foundations: urban flows, hydrologic flows, and ecological flows. Urban Flows represent the tangible and intangible elements in the urban context. Tangible elements are the existing transportation networks, bridges, land uses, infrastructure, parks, and built structures of the territory. Intangible elements consist of urban districts, such as Chinatown, Boyle Heights and Pico Aliso, and the observance of social, cultural, and political forces. Hydrologic Flows highlight the dynamic forces of the fluvial environment neglected by the current channel configuration. The dynamic flows and flood events represent opportunities to accentuate the phenomena. Conditions of low-flows, bi-annual flooding, 50-year events, and slug flows are used as generative forces in the reconfiguration of the channel. Ecological Flows observe the role of the river in reestablishing an ecological continuum of habitat diversity. Islands, patches of trees, basins, plains and pond areas represent the initial ecological framework of the natural processes in the river corridor. The Los Angeles River is at once engineered and natural, dynamic and contained. Can this paradox be used to liberate the river and create a new landscape integrating ecology, engineered structures, and architecture? Building on the conceptual foundation this project extends the paradox and identifies three intervention strategies as a framework for development of the river corridor. todd wenskoski 80 edge 81 Hydrologic Flows Ecologic Flows Urban Flows | 1 Urban Flows | 2 Urban Flows | 1 Urban Flows | 2 Urban Flows | 3 Hydrologic Flows Ecologic Flows todd wenskoski 82 edge 83 Flow Strategy todd wenskoski 84 Armature Strategy edge 85 Flood Events Phasing Strategy todd wenskoski 86 edge 87 Urban Piers This design focuses on the Union Pacific Rail Yard and a two-mile stretch of the concrete channel to the south. The Rail Yard plan programs the space as a regional park system and creates activity planes that allow for interaction with the channel. A system of piers extends the urban fabric into the channel creating space for human connection with the river. A north to south corridor along the river edge connects existing roadways with a link along the western edge of the Union Pacific Rail Yard. On this site water is diverted from the low flow channel and pushed into a set of landforms creating a wetland that would serve as a regional park. The water at the base of these landforms supports a large variety of native plant material. A large plinth supports an athletic center with sports fields that juxtapose with a tilted plane that leads down into the wetland. Connections are established through the Rail Yard site on two levels. Human scale connections are created through the park by two perpendicular promenades. New vehicular connections are created on the northern and southern edges of the site. North to South Connection Water Flow Urban Extension River Development and Pier Relationship This plan proposes a redeveloped Pico Aliso community with associated civic facilities, as well as a large retail center and a set of public buildings catering to the community. The opportunity exists to create a relationship with the river through open spaces in the development. Connections from north to south and east to west reinforce the relationship between the river and the city and move people through these spaces on a daily basis. This exposure to the river exists on several levels through implementation of the piers, low flow diversion channels, and points of community connection. brad cantrell 88 edge 89 Union Pacific Rail Yard North Union Pacific Rail Yard South Building Pier Festival Pier Community Pier brad cantrell 90 edge 91 Alternate Systems This project took as a basic assumption that the studio client, the Friends of the Los Angeles River and the Santa Monica Mountain Conservancy, will be the instigators of change in this section of the Los Angeles River. Given the contentious political situations in any city, especially Los Angeles, this project looked at developing a series of typologies that could be used to inform decisions about the river as various parcels come under control of the interested parties. The overarching goal of the strategy was to provide housing and open space in a city that is in desperate need of both. After looking at the constricting land uses around the river, and being mindful of the river's desire to flow along the most direct route, a series of interventions are proposed. These changes fall into three levels: a major level of intervention culminating in a soft bottom channel and removal of the channel wall, an intermediate level of intervention that does not alter the friction of the channel bottom but does remove at least portions of the wall, and a final level that does not alter the channel bottom or wall. After identifying a series of opportunities along the river, the project looks at each condition in detail, and offers site-specific solutions for incorporating housing and open space into a design. These studies are not meant to be definitive, but rather an example of what can be accomplished in any of the three given conditions. Some of the highlights of these investigations include a soccer arena in the channel bottom of the Los Angeles River, with seating incorporated into the existing channel wall, a series of shifting mounds that change shape with the yearly floods, and a minimalist intervention into the channel bottom that collects vegetation during the low flow season, and is washed away during the highest flows. Constricting Land Use Open Space Opportunities By developing a framework from which to view the opportunities, the concerned parties in Los Angeles will be able to see how a small, presently available parcel of land might relate to a larger scheme that incorporates the entire length of the Los Angeles River. wes michaels 92 edge 93 Union Pacific Rail Yard Field wes michaels 94 edge 95 groundwork 9 8 |los angeles river history 1 0 8 |landuse analysis maps 1 2 2 |hydraulics information 1 3 0 |precedents los angeles river history a million years ago A period of strong mountain growth occurred The rising mountains had faults which rapidly eroded The Santa Monica mountains reached over a thousand feet in height The San Gabriel mountains were up to seven thousand feet high Alluvial deposits of several thousand feet filled the basins and coastal plain river history 98 groundwork 99 1781 Zanja Madre ditch built 1811 Flood 1815 River floods and changes course at Alameda and Fourth Street cutting west and emptying into Ballona Creek 1825 River changes its course back from the Ballona wetlands to San Pedro Woodland between the pueblo and the ocean destroyed Marshland drained by the new channel 1832 Flood 1860 First wells drilled 1861-1862 Heavy flooding Fifty inches of rain falls during December and January Much of San Fernando Valley is under water City's embankment and Dryden's system are destroyed 1867 Floods again spill over the old channel and create a large, temporary lake out to Ballona Creek 1876 The Novician Deluge Transcontinental railroad is a catalyst for population explosion Trestle railroad bridges formed dams during floods breaking and unleashing a flood of debris 1884 Heavy flooding causes the river to change course, turning east to Vernon and then southward to San Pedro The downtown section of the river is channelized 1886 5 million gallons a day being taken from river Infiltration galleries capture underground river flow 1888-1891 Annual floods Reservoirs are added to store captured flow 1892 10 million gallons of water a day being taken from river black and white photography by Stephen Callis 1898-1904 The area of artesian water shrinks 33 percent Potential of river as water source is governed by average dry season flow This was measured in early twentieth century at 45-50 million gallons a day Zanjas are abandoned and filled The deposition of sediments from the eroding mountains fills channels causing channel location to change Sand and gravel are quarried from river bed and rubbish was dumped in LA river 1815-1825 river history 100 groundwork 101 1913 Owens Aqueduct built 233 miles from Los Angeles River - passes through Mojave desert, through tunnel in San Gabriel mountains and into reservoir in Northern San Fernando valley The Owens collects snowmelt from 40 mountains The new aqueduct can supply 325 million gallons a day, seven times the ammount available from the LA River alone 1914 Flood Great damage to the harbor Silt deposits from flood fills Los Angeles and Long Beach harbors stranding ships and ruining navigation channels Disscussion of channelizing the river begins 1915 3,000 acres of intensive agriculture in the San Fernando valley Levees built are routinely washed away Depression - height of transient life in river basin 1921 Moderate flood 1930 70,000 acres of intensive agriculture San Fernando Valley More infiltration galleries built to divert river Goal is to keep river bed dry for water quality and because water flowing away is wasted water 1934 New Year's Day Flood in La Canada Valley killed 49 people, destroyed 198 homes and caused 6.1 million in damages (73.4 million today) - most damage done by debris flows 1935 Pres. Roosevelt approved WPA work supervised by Army Corp of Engineers The Plans include Concrete Channelization, Raising/Strengthening of Bridges, Enlarging Channels, Debris Basins and Detention Basins 1938 Great county-wide flood with 4 days of rain Recorded as a 50 year storm Army Corps of Engineers begins channelizing the river 1940 Hansen Dam controlling Tujunga Wash built Second major aqueduct from Colorado River Railroads and stockyard industry lines the river storm drains - untreated sewage flowed in 1941 Congress approves Army Corps of Engineers Plan Los Angeles County Drainage Area Project 71.8 million for flood control in watershed/tributary streams, 35 million spent on river 3 more large flood control basins, 33 debris basins at bases of mountain canyons, 300 bridges to be built Sepulveda Flood Control Basin is single most expensive at 6.7 million - an earth filled dam 2.9 miles long, 57 feet high, storage capacity of 16,700 acre feet 1941-1944 LA river floods five times LA river 1825-1889 river history 102 groundwork 103 1948 Los Angeles River Pollution Committee begins sampling and surveying river water discharges - ends the worst point-source pollution 1950 Throughout the 1950’s perpetual construction, 5 days a week, 24 hours a day Construction moved twenty million cubic yards of earth 3.5 million barrels of cement 147 million pounds of reinforced steel 460,000 tons of stone 1952 Moderate flooding 1959 Last section finished, beginning of new channel was near Chatsworth Hills Mountain, San Pedro Bay Flood control increased area that could be built upon, however, people continue to build on foothills where mudslides and debris flows can kill and destroy homes The development of the San Fernando Valley reduced the land’s natural ability to absorb and regulate floods 1969 One heavy flood after 9 day storm One moderate flood 1970 New channels on 100 miles of river and 370 miles of tributary to handle population growth 5 major flood control basins in San Fernando and San Gabriel Valleys 11,441 acre feet 15 smaller flood dams 129 debris basins in hills Channelized 47.9 miles of the river 1971 Shut down Headworks Deep Infiltration Gallery because of water quality Nearly all of the water flowing in the river is treated sewage, authorized industrial discharges, and street run off 1978 Two moderate floods 1980 Flood tops banks of river in Long Beach Most wells closed Channelization reduced the length of the river by 28% Average width had been 70-140 feet is now 260 feet Average depth had been (1903) 4-6 feet is now 17 feet Most common contaminants are trichloroethylene and perchloroethylene widely used in small industry, metal platers, machinery degreasers and dry cleaners Places not connected to municipal sewage 1982 Shut down Headworks Spreading Grounds 1983 Flood 1984 LA river 1889-pre-channelization river history 104 groundwork 105 Donald Tillman Water Reclamation Plant in Van Nuys provides 1/3 of river flow starting just above Sepulveda Dam City of Burbank Reclamation Plant Los Angeles/Glendale treatment facility near outlet of Verdugo Wash EPA began San Fernando Valley Superfund site - a cleanup program continues today 1990 All wells closed 1991 Army Corps proposes to raise levees from Rio Hondo to Long Beach to protect against a 100 year flood 1992 15 year flood 1993 109.5 million gallons a day near Arroyo Seco more than double the flow of 1902 above the diversions 10 - 15% of the of LA water supply is still pumped from beneath San Fernando Valley Less than 5% comes from historic basin Storm Drains provide 30 % of flow 1994 Heavy flooding Estimates range from a 15 to over a 100 year flood 2001 In other cities, the 40-50 million gallons of water a day that Los Angeles uses would supply 400,000 people Los Angelenos have historically used 3 times as much water as other people Highest per capita use of water of all US cities, much of it going into gardens New water treatment diverts river water into Headworks Spreading Grounds north of Griffith Park and percolates it for a year then redraws it as passable drinking water Could provide 10% of LA water supply Project on hold until conclusion of EPA cleanup River has most extensive set of controls for a river of its size in the world Storm fed runoff can reach speeds of 30-40 miles an hour LA river channelized river history 106 groundwork 107 sub watersheds legend landuse analysis maps 108 groundwork 109 hydraulics urban built areas landuse analysis maps 110 groundwork 111 parks, public open space and natural features LA river studio site landuse analysis maps 112 groundwork 113 local access points for future development green spaces landuse analysis maps 114 industrial sites suitable for redevelopment landuse groundwork 115 areas in need of more schools public facilities landuse analysis maps 116 areas resistant to change existing schools groundwork 117 population densities predominant ethnicity landuse analysis maps 118 population aged 0-17 population aged 18-64 groundwork 119 bicycle corridors roadway network landuse analysis maps 120 rail corridors school locations groundwork 121 Aggradation The process by which a stream bed is raised in elevation by deposition of sediment (opposite of degradation). Capillary Fringe The unsaturated zone immediately above the water table containing water in direct contact with the water table. Alluvial Term used to describe material deposited by running water. Carrying Capacity The number or mass of organisms of a species that can live in a given area. Aquifer One or more geologic formations containing sufficient saturated porous and permeable material to transmit water at a rate sufficient to feed a spring or for economic extraction by a well. Channel A waterway with obvious banks that contains moving water at least part of the year. Artificial Recharge The deliberate act of adding water to a groundwater aquifer by means of a recharge project; also, the water so added. Artificial recharge can be accomplished via injection wells, spreading basins, or in stream projects. See also incidental recharge, natural recharge, and recharge. Base Flow Streamflow derived from groundwater seepage into the stream. Basin The total area of land that drains water to a central stream, river or other water body. Also called Drainage Basin. Bioengineering In soil applications, refers to the use of live plants and plant parts to reinforce soil, serve as water drains, act as erosion prevention barriers, and promote dewatering of water laden soils. Biotechnical In slope stability engineering refers to the use of both live plant material and inert structures to stabilize and reinforce slopes. BMPs Best Management Practices. Managerial techniques that are recognized to be the most effective and practical means to control pollutants yet are compatible with the productive use of the resource to which they are applied. BMPs are used in both urban and agricultural areas. BMPs include: reducing paving areas and increasing plant cover, using gray water for irrigation, filter beds, subsurface infiltration basins, green trellises for shade, cisterns for roofs and playgrounds, permeable parking areas, regarding for onsite infiltration, green roofs, cistern walls, green planning, green screens, vegetated creeks/drainage channels, parking orchards. Channel Route Channel Route must take into consideration surrounding land uses and topographic constraints. With the Los Angeles River located within a highly urbanized area the channels existing route cannot be lasted to a great degree. Consumptive Use A use that makes water unavailable for other uses, usually by permanently removing it from local surface or groundwater storage as the result of evaporation and/or transpiration. Does not include evaporative losses from bodies of water. See non-consumptive use. Coefficients of Runoff Are measured in feet per second. In urban areas, typical coefficients include: downtown 0.70-0.95, shopping centers 0.70-0.95, single family residential (5-7 houses per acre) 0.350.50, attached residential 0.60-0.75, suburban (1-4 houses per acre) 0.20-0.40, light industrial 0.600.90, heavy industrial 0.20-0.80, railroad yard 0.200.80, parks/cemeteries 0.10-0.25, playgrounds 0.20-0.40. Contaminant Plume A zone of polluted groundwater down-gradient from a point source of pollution. Cover Any object in the stream that provides protection to fish and other animals. Fish use cover to hide, rest, escape and feed. Dams/Weirs Used for ponding water in a river. Often used to prevent sediment flow downstream. Degradation The process by which a stream bed is lowered in elevation by removal or scouring of sediment (opposite of aggradation). This term is also used to refer to a damaged condition of habitat. Deposition The process of sediment falling out of the water onto the stream bed in areas of lower flow and energy Detention Ponds Controls flooding by diverting water during peak flow times. Usually placed out of channel. Hold water temporarily, as opposed to Retention Pond (see below). Detention facilities are dry ponds which become completely dry within 24 hours of a storm event. Extended detention facilities store the first flush (normally the first ½" of runoff) of stormwater runoff for a period of time between 24 hours and 72 hours. After 72 hours, the bottom of the facility will be dry until the next storm event. Detention of stormwater runoff provides water quality benefits by allowing some pollutants to precipitate from the water before being discharged to receiving streams. Discharge The volume of water that flows past a given place during a certain amount of time. Discharge is often referred to in cubic feet per second (cfs). DO Dissolved oxygen. The amount of oxygen that is dissolved in water. It also refers to a measure of the amount of oxygen available for biochemical activity in water body, and as indicator of the quality of that water. Eddy A circular current of water usually formed at a bend or obstruction in the stream. Effluent Treated wastewater discharged from sewage treatment plants. See tertiary treatment. Erosion The wearing away of rock or soil and the movement of the resulting particles by wind, water, ice, or gravity. Estuary The area where fresh and salt water mix at the mouth of a river. Estuaries are important areas that are used as rearing habitat by many fish species and other animals. Evaporation The process of liquid water becoming water vapor, including vaporization from water surfaces, land surfaces, and snow fields, but not from leaf surfaces. Compare with transpiration. Evapotranspiration The sum of evaporation and transpiration. Floodplain The low area along a stream into which water spreads during a flood. 100 Year Floodplain Those lands that are subject to a one percent or greater chance of flooding in any year. Floodway Those portions of the floodplain adjoining and including the channel of a river or stream which discharges the flood water and flow of that water or stream. It is any place where the water is moving with velocity and a definite current, but does not include other portions of the floodplain where the water is just standing. Flow Resistance Channel material can either increase of decrease friction, thus slowing down or speeding up the water. Factors that contribute to flow resistance include: sediment and grain size, bed forms including ripples, dunes, bars, pools and riffles, river sinuosity, water depth to grain size, sediment transport, and vegetation. As more objects and obstructions are introduced into the channel it becomes hard to predict channel flow and water turbulence. Freshet A rapid rise in stream flow due to runoff from rain or snowmelt. Gabions Used in a variety of forms to stabilize slopes. Durable and porous. May be used with plants. Gaging Station A site on a stream, lake, reservoir or other body of water where direct systematic observations of hydrologic data are obtained. Gradient The amount that a stream drops in ele- hydraulics 122 groundwork 123 vation over a distance; the stream's steepness. infiltrate more quickly than gravelly soils. The practicability of infiltration depends on groundwater elevations, the depth to bedrock and the infiltration rate. Instream Flow - The amount of water remaining in a stream without diversion that is required to maintain a particular aquatic environment or water use. Green Slope Stabilizers There are a variety of slope stabilizing methods that involve the use of grass and vegetation. Groundwater Subsurface water body in the zone of saturation or more commonly, available groundwater is defined as: That portion of the water beneath the surface of the earth that can be collected with wells, tunnels, or drainage galleries, or that flows naturally to the earth's surface via seeps or springs. Hydraulic Continuity The term refers to the Intragravel Flow Water that moves between gravel or other particles in the stream bed; important for fish eggs and young fish in the gravel. natural interconnection between ground and surface water. Mainstream The principle stream or river of a particular basin. Hydrologic Cycle The cyclic transfer of water vapor from the earth's surface via evapotranspiration into the atmosphere, from the atmosphere via precipitation back to earth, and through runoff into bodies of water. Meander A turn or winding of a stream. Incidental Recharge Water incidentally added to a groundwater aquifer due to human activities, such as excess irrigation water applied to fields or water Natural Recharge Naturally occurring water added to an aquifer. Natural recharge generally comes from snowmelt and storm runoff. See also recharge, artificial recharge, incidental recharge. Non-Consumptive Use A use that leaves the water available for other uses. Examples are power generation and recreational uses. See consumptive use. water away from, the channel. Point Source A source of water pollution that originates from a single point, such as an outflow pipe from a factory. See NPS. Pool A part of the stream that is usually deeper than the surrounding water and has slower current. Pools are often formed by scouring under or around an obstacle, by plunging over logs or rocks, or by side channels. Pool-Riffle Ratio The total area of pools compared to the total area of riffles in a stream. In habitat restoration we often try to increase the number of pools by adding large woody debris. Most healthy streams in forested areas have a high pool-riffle ratio. Potable Water Water of a quality suitable for drinking. Primary Treatment A physical process in which the sewage flow is slowed down in settling tanks or NPS Nonpoint source pollution. Occurs when water runs off land or through the ground, picks up pol- lutants, and deposits them in surface waters or introduces them into groundwater. Pollution that does not come from a single source, such as a pipe or ditch. discharged as waste after a use. See also recharge, artificial recharge, and natural recharge. Off-Channel Habitat Ponds Channels or wetlands that are connected to the main channel of a stream. Infiltration Ponds Infiltration allows the water to seep into the ground and recharge the groundwater. The infiltration rate or how quickly the water enters the ground depends on the type of soil. Sandy soils Outlets/Inlets Used to bring water into, or take hydraulics 124 lagoons. The thicker part of the wastewater, the sludge, is then removed from the bottom and disposed of in a variety of ways. Floatable solids, oil groundwork 125 and grease are usually skimmed off the surface before the remaining effluent is discharged into a water body. biological filters are two of many methods of secondary treatment. Sediment The silt, sand, rocks, wood and other solid material that gets washed out from some places and deposited in others. Prior Appropriation Doctrine The western system of water appropriation that establishes water rights based on the seniority of use, i.e. an individual's right to a specific quantity of water depends on when the use began. Rapids Steep section of stream with swift current and lots of surface agitation and some waves. Recharge To add water to an aquifer; also, the water added to an aquifer. See also artificial recharge, incidental recharge, and natural recharge. Retention Ponds Retention facilities or wet ponds permanently pond water. Wet ponds also provide water quality benefits by allowing pollutants to precipitate from the water before discharging into receiving streams. Wet ponds increase the temperature of the water stored in the pond. These increased temperatures can adversely impact the cool waters required for trout. Riffle Shallow rapids with surface agitation, but no waves. Rill A tiny drainage channel cut in a slope by the flow of water. Can develop into a gully with continuing erosion. Stream Bed The stream bottom. Rock Job Bank stabilization achieved by lining the stream side with rocks or rip rap. Rootwad The mass of roots of a tree. Rootwads of fallen trees in the stream can form large pools and provide excellent cover. Run Swiftly flowing part of a stream with little surface agitation and no major obstructions. Runoff That part of rain and snowmelt that runs over the ground and into a stream or other water body. Scour Removal of sediment from the stream bed by flowing water. Secondary Treatment Also known as biological treatment, further reduces the amount of solids by helping bacteria and other microorganisms consume the organic material in the sewage. Oxygen is critical to this treatment stage. Air activated sludge and Streamflow The discharge that occurs in a natural channel. A more general term than runoff, streamflow may be applied to discharge whether or not it is affected by diversion or regulation. Subcritical Flow Subcritical flow is classified according to the flows Froude number which is a speed to length ratio. Subcritical flow is less than one. Subcritical flow causes less erosion problems. Supercritical Flow Classified according to a Froude number which is a speed to length ratio. Supercritical flow is more than one. Concrete portions of the Los Angeles River have Supercritical flow, but erosion is not an issue. Supercritical flow is purposefully engineered to help speed up flow, under low bridges. In a case like this it is cheaper to create baffles which cause supercritical flow, than to make the bridge higher. Tailout The shallow area where water flows out of a pool. Thalweg The deepest area running along the stream bed. Usually where the fastest water runs. Riparian Anything associated with the banks of a stream, river or other water body. Often used to describe the vegetation along a stream. TMDL Total Maximum Daily Load. The federal Clean Water Act (CWA) section 303(d) addresses waters that are not "fishable or swimmable" by requiring each state to identify the waters and to develop total maximum daily loads (TMDLs) for them, with oversight from the U.S. Environmental Protection Agency (EPA). A TMDL is an assessment of how much pollution "load" the stream can accept and still meet federal and state water quality standards. A TMDL allocates pollution control responsibilities among pollution sources in a watershed, and is the basis for taking the actions needed to restore a water body. The Washington DOE administers the TMDL process for the EPA in this state. Technically, Total Maximum Riparian Habitat Natural home for plants and animals occurring on the land bordering a stream or river. Rip-Rap Used for lining banks and as an apron for outlet pipes. May be washed away in high flow times if not properly used. Grouted rip-rap is an option to add stability to the material. Rip-rap is porous and may be used with plants. hydraulics 126 Daily Load (TMDL) is the sum of the individual waste load allocations (WLAs) for point sources, load allocations (LAs) for nonpoint sources and natural background, and a margin of safety (MOS). TMDLs can be expressed in terms of mass per time, toxicity, or other appropriate measure that relates to a state's water quality standard. Tributary A stream that feeds into a larger stream. Also called a "feeder stream." Water Information for Los Angeles Hydrometeorology. Coastal and Mountain Areas. Precipitation (rainfall) in the Los Angeles area occurs primarily in the form of winter orographic rainfall associated with extra tropical cyclones of North Pacific origin. Major storms consist of one or more frontal systems and occasionally last four days or longer. Air masses and frontal systems associated with major storms commonly extend for 500 to 1,000 miles in length and produce rainfall simultaneously throughout the County. Major storms approach Southern California from the west or northwest with southerly winds which continue until frontal passage. The mountain ranges lie directly across the path of the inflow of warm, moist air, and orographic effects greatly intensify precipitation. The seasonal normal rainfall in Los Angeles County groundwork 127 ranges from 27.50 inches in the San Gabriel Mountains to 7.83 inches in the desert. The annual County average for the annual rainfall for Los Angeles County is 15.65 inches. The effects of snowmelt upon flood runoff is of significance in the few cases when warm spring rains from southerly storms fall on a snowpack. During major storms, temperatures throughout the County may remain above freezing. Average individual storm rainfall amounts and intensities conform to a fairly definite aerial pattern which reflects general effects of topographic differences. Desert Areas Summer convective rainfall is principally experienced in the upper San Gabriel Mountains and the Mojave Desert regions. In many desert areas, the most serious flooding occurs as a result of summer convective storms. Runoff. Mountain Areas. In mountain areas, the steep canyon slopes and channel gradients promote a rapid concentration of storm runoff . Depression storage and detention storage effects are minor in the rugged terrain. Soil moisture during a storm has a pronounced effect on runoff from the porous soils supporting a good growth of deep-rooted vegetation such as chaparral. Soil moisture deficiency is greatest at the beginning of a rainy season, having been depleted by the evapotranspiration process during the dry summer months. Precipitation during periods of soil moisture deficiency is nearly entirely absorbed by soils, and except for periods of extremely intense rainfall, significant runoff does not occur until soils are wetted to capacity. Due to high infiltration rates and porosity of mountain soils, runoff occurs primarily as subsurface flow or interflow in addition to direct runoff. Spring or base flow is essentially limited to portions of the San Gabriel Mountain range. Consequently, most streams in the County are intermittent. Runoff from a mountain watershed recently denuded by fire exceeds that for the unburned state due to greatly increased quantities of inorganic debris present in the flow and increased direct runoff resulting from lowered infiltration rates. Debris pro- duction from a major storm has amounted to as much as 223,000 cubic yards per square mile of watershed. Boulders up to eight feet in diameter have been deposited in valley areas a considerable distance from their source. Debris quantities equal in volume to storm runoff, representing a 100 percent bulking of runoff from a major storm, have been recorded. Where debrisladen flow traverses an alluvial fill unconfined by flood control works, flood discharges follow an unpredictable path across the debris cone formed at the canyon mouth. Hill and Valley Areas. In hill areas, runoff concentrates rapidly from the generally steep slopes; however, runoff rates from undeveloped hill areas are normally smaller than those from mountain areas of the same size. In those hill areas which have been developed for residential use, concentration times become considerably decreased due to drainage improvement, and runoff volumes and rates have increased due to increased imperviousness. On the other hand, erosion is controlled and debris is minimized from storm flows. Debris production rates from undeveloped hill areas are normally smaller than those from mountain areas of the same size. drainage area from another. Wetland Land with a wet, spongy soil, where the water table is at or above the land surface for at least part of the year. There are a number of different wetlands indicators (soil type, plants, etc.) that determine whether a piece of land is legally considered a wetland. Wetted Perimeter Is the area of water that is in contact with the channel. The wetted perimeter is calculated by adding the breadth and length that is in contact with the water. The most efficient cross sectional shape for a wetted perimeter is an elliptical or radial shape. This shape is obviously harder and more expensive to construct than the trapezoidal channel which most closely approximates the radial shape. Wire Walls Used as a gravity wall. Wire walls are filled with soil, and the face of the wall is anchored by the weight of the soil. Wire Walls can be designed with or without a step enabling construction of a flush-face vertical structure. In highly developed valley areas, local runoff volumes have increased as the soil surface has become covered by impervious materials. Peak runoff rates for valley areas have also increased due to elimination of natural ponding areas and improved hydraulic efficiency of water carriers such as streets and storm drain systems. 30 to 40 percent of the water used in the County is pumped from groundwater supplies. The growth of the County, combined with periodic droughts, seriously depleted these supplies on numerous occasions throughout the history of the County. source: www.lalc.k12.ca.us/target/units/river/tour/hist.html Water Table The upper boundary of a free groundwater body, at atmospheric pressure. Watershed The area drained by a river or stream, including the area drained by its tributaries. Natural watershed boundaries are ridges that divide one hydraulics 128 groundwork 129 Flooding Zone at the Petit Gironde 1989 Les Ponceaux, Coulaines, France Pascale Hannetel and Anouk Debarre The design scheme for this park involved the creation of four dry detention ponds along the Petite Gironde stream. Periodic flooding had been exacerbated by runoff from adjacent urban developments. The opportunity for the ponds to be used by the town as a park was an integral part of the client's brief. The site is approximately 600 meters long and 100 meters wide. There are four ponds on descending levels, capable of absorbing a maximum of 35,000 cubic meters of water. The design of the ponds allows for consistent circulation despite the rise and fall of the water level. An underground drainage system installed in the top pond prevents overflow during extreme flooding. The detailed landscape elements in each of the four ponds reveal the water in a variety of ways. A series of grassed dykes in the uppermost pond jut out from the side embankments and cross the flow of water like pontoons or ships, thus creating rough eddies and rills in the moving water. The lower ponds become progressively richer in vegetation while densely planted beds slow the water. These beds appear as tranquil islands during periods of inundation. petit gironde 130 precedents 131 Emscher Park 1989-1999 Ruhr, Germany Blick Von Westen Lats & Partner Seepark Lünen Post Industrial Area, a land reclamation project, encompasses 200 square miles. Seepark Lünen offers newly laid-out avenues, the impressive backdrop of a lake, and a variety of landscapes showing nature lovers a unique environment. An ecological renewal and development area that was previously marked by mining, the Seepark site now hosts a regional garden show. The industrial heritage of the site remains perceptible - a waste dump still exists on site and shows the history of a landscape ill treated by mining. Seepark Lünen attracts visitors by allowing the structural and material remains of heavy industry to blend with inspired lakeside landscapes, creating a series of extraordinary spaces. emscher park 132 precedents 133 Louisville Waterfront Park 1990-Present Louisville, Kentucky Hargreaves Associates The Louisville Waterfront Park is made up of a series of varied, flexible and programmable spaces: a working wharf, Festival Plaza, Overlook, Great Lawn, and 80 acres of environmentally sensitive parkland with strolling trails, native riparian plantings and wetland development. The entire project is graded to provide flood protection, while simultaneously promoting visual interconnection between the city and the river. The project required the development of creative and original engineering solutions for problems such as barge wake. A bumper system was also developed to protect the structural supports of the Great Lawn and Overlook, which actually extend over the river on piers, from the potential for barge collisions. louisville waterfront park 134 precedents 135 Parc Corbiere 1993 Le Pecq-sur-Seine, France Pascale Hannetel, Anne-Marie Werckle & Arnaud Yver Parc Corbiere was built along the Seine River on alluvial banks created by erosion. An island by the same name had once been located offshore. The designer's strategy was to transform this boggy marsh into two distinct terraces separated by a raked embankment. The upper terrace connects with the main road leading to the adjacent town. It consists of a formal oak-lined avenue atop of the embankment. The path connects with an existing aqueduct and utilizes an archway as an entrance to the park. A lookout point is provided, as are small flights of stairs leading down to the lower terrace, thereby extending the street grid into the park. The lower terrace accommodates the Seine's frequent rise in water level. It has been recreated as a water meadow that acts as a filter during floods. Tree plantings of willow, dogwood, and ash trace the outline of this space and fill the area of the former island. park corbiere 136 precedents 137 Potsdamer Platz 1996-1999 Berlin, Germany ARGE Dreiseitl/Piano/Kohlbecker A unique urban water system was created, covering an area of approximately 2.5 acres, as part of the renovation of this large square in Berlin. Holding approximately 12,000 cubic meters of water and reaching a maximum depth of 6 feet, the water system has a mile-long shoreline and flows in the midst of tall office and cultural entertainment buildings. The innovative landscape design fulfills ecological functions to protect ground and surface water by: extensive and intensive planting of greenery on the roofs of a major portion of the buildings, collecting of rainwater in cisterns for toilet flushing and irrigation, and feeding an artificial water system for floodwater protection, rain water retention and temperature moderation via cisterns. Changing water levels allow storm concentration to be buffered and fed at a lower speed into the canal. This also considerably reduces the direct entry of pollutants contained in rainwater. To keep the urban basins aesthetically attractive, the water passes through various steps in a closedcircuit biotope cleansing system. The re-circulated water inflow occurs predominantly through reed beds along the shoreline in all three basins, effecting a physical, biological and chemical cleansing. The outflow from the Main and South Basins occurs through bottom drains embedded in gravel filters. Flow simulation studies identify possible stagnation areas and determine the optimal intake and outflow ratios. During periods of high turbidity the outflow can be routed through micro filters eliminating even the smallest algae particles. Chemical additives are never necessary. potsdamer platz 138 precedents 139 Mill Race Park 1989-1993 Columbus, Indiana Michael Van Valkenburgh, Landscape Architect Stanley Saitowitz, Architect Before transformation, the landscape on this site was desolate. A tannery and various ramshackle structures inhabited the space. The concept of the new design was to enhance public life and to symbolize the spirit of the city of Columbus while also allowing for complete flood inundation. The design allows existing structures to become parts of new facilities and defines both circulation routes and activity programming. A covered bridge links the geometry of the town to the irregular contours of the riverbank. Visual and physical access to the site's natural features, especially to the river, has been enhanced. mill race park 140 precedents 141 San Antonio River Walk/Paseo del Rio 1939-1941 San Antonio, Texas Robert Hugman, Project Concept WPA Project The San Antonio River Walk, or the Paseo del Rio, is a public space along the San Antonio River that provides both a source of commercial development and green space for the public to occupy. The River Walk features a lush, carefully maintained landscape and is lined with restaurants, outdoor cafes, shops, nightclubs, and an open-air theater. The River Walk's proximity to the Alamo ensures that it a popular tourist attraction. The River Walk is located 25 to 30 feet below street level and is primarily used by pedestrians. There are 50 staircases throughout San Antonio that bring pedestrians down to the walk, and 19 bridges cross the river. The corridor of the River Walk is 60 to 100 feet wide at river level and approximately 100 to 300 feet wide at street level. The river itself is 30 to 50 feet wide. Because the water level is controlled in the Paseo del Rio, the walkways along the river are only 6 to 8 inches above the water level and are not separated from the water by railings. This allows pedestrians intimate access to the water. The River Walk is sunken and, therefore, has a relatively constant temperature and higher level of humidity than the surrounding area. This microclimate allows the River Walk to become a botanical garden of sorts; plants from sub-tropical climates flourish in the steady, humid climate along the river. san antonio river walk 142 precedents 143 Rio Salado/Tempe Town Lake Master Plan 1990 Phase 1 Construction 1999 Tempe, Arizona ASU Student Master Plan Rio Salado is an arid river water project in a large western urban zone characterized by sudden, violent, and rapid water fluctuations. Tempe Town Lake is a 5-mile (220 surface-acre) lake created on the Salt River running through Phoenix, Arizona. Located directly adjacent to Downtown Tempe, commercial and development interests are the primary forces shaping lakeside land use. The Lake was created through the use of new inflatable dam technology; the dams are placed at either end of the Lake zone creating adjustable water barriers. Although the inflatable dam technology is a new technique, the broader attitude of capturing a large body of water in Western areas has been conventional practice. Unlike other dam projects, where waterpower has been harnessed as an energy source, the Tempe motivation focused on recreational and economic benefits to the area. rio salado 144 precedents 145 Rhone Embankment 1993 Lyon, France Renzo Piano, Building Workshop Michel Corajoud, Atelier Corajoud Bernard Lachat Biotechnology, Silene Biotec A new district known as the Cite Internationale is coming into being at a bend of the Rhone River in the east of Lyon. The architect Renzo Piano won the respective design competition in 1986 and later called in the landscape architect Michel Corajoud to turn the buildings and the open spaces into a homogenous whole. Michel Corajoud integrated the pioneer vegetation growing on the sandbanks at the end of the Cite Internationale site in Lyon into his planning scheme. Main principals of the design include: creating a contiguous strip along the length of river in which vegetation alternates with existing and new buildings, and reducing the impact of several overpowering species such as Japanese knotgrass and black poplars by replacing them with less invasive species. The project also creates transverse links and transitions between strips of vegetation and introduces a jetty that runs out to the banks and into the river, thereby providing visitors with access to sensitive zones. Engineering processes included sowing a biotextile matting carpet of forbs and planting individual groups of trees. The convex bank was reinforced with plants to prevent erosion. rhone embankment 146 precedents 147 Shop Creek Stream Restoration 1988-1989 Aurora, Colorado Wenk Associates Shop Creek, located just east of Denver, drains into the city of Aurora's reservoir, which provides flood control and recreational opportunities for the citizens of Denver. Like much of the Denver area, Aurora experienced rapid growth over the past few decades. Extensive urban development within the Shop Creek watershed increased the volume of runoff, phosphorus load, and sediment load in the storm waters entering Shop Creek, while increased flow levels in the creek caused extensive stream-bank erosion upstream of the reservoir. Also, sediment and phosphorus from the entire Cherry Creek watershed had caused algal bloom in the water, reducing its appeal for swimming and boating. Improvement to Shop Creek was an important component of the overall plan to improve water quality in the Cherry Creek Reservoir. The design team rejected an earlier plan for the creek, which involved confining it to a uniform channel. Instead, this new design relied on biofiltration, detention, and infiltration. The restored creek first enters a partially vegetated detention pond that provides initial settling of sediment and uptake of nutrients. Allowing suspended particles to settle out removes absorbed phosphorus from the water. From the pond, water follows the existing, sinuous course of the creek rather than the straight channel originally envisioned. Terraced, crescent-shaped drop structures built of soil and cement periodically interrupt the channel, slowing stream flow and reducing erosion. Constructed wetlands along the creek's banks further reduce phosphorus through biological uptake and provide stability to the stream bank. shop creek 148 precedents 149 South Platte River 1980, continuing Denver, Colorado MGD, Inc. Denver's South Platte River Greenway offers city dwellers ready accessibility to trails and parks for a variety of recreational riverside pursuits. Once an urban blight and a dumping ground for local businesses, the South Platte River running through downtown Denver is now a resource. A series of enhancements, including the construction of a sequence of trails, parks and boat launches, allow the river to be accessible to the people. The site's inherent obstacles, such as poor access and scattered dumps along the river, have been turned into opportunities to extend trails that reached the river and to turn landfills into parks. Ten and a half miles of bike trails and 17 mini-parks enhance the riverfront and bring to the local residents pride and ownership of the greenway. The River Foundation hosts an annual river cleanup, which further connects the community to their river. south platte river 150 precedents 151 Guadalupe River Park 1998 San Jose, California Hargreaves associates The Guadalupe River is subject to the intermittent, sporadic floods typical of the western United States. The Guadalupe River Park is a paradigm of a modern flood-control project integrated with a major recreation park and wildlife habitat. It assures nature a place in the center of San Jose - a legacy to last for generations. The River Park underlay consists of the grading plan for the flood-control channel itself; it provides a structural spine for the design of the River Park. Undulating terraced banks and landforms enforce the manmade, river-influenced backbone of the native riverbank landscape. The second level, or River Park overlay, consists of a design, currently in development, for open spaces, events and habitat restoration along the channel. guadalupe river park 152 precedents 153 epilogue 1 5 6 |epilogue Epilogue Designing the physical transformations for this section of the Los Angeles River is a big project. As the studio studied the site and developed proposals, the scale and the importance of the undertaking continued to be underscored. However, with time the project became less daunting as the students' work revealed three approached based on bank manipulation. First, there is an approach that would initiate a dramatic land use change above the river channel. This tactic is best exemplified on the 100+ acre railyard site, but at a smaller scale a land use change above bank could also have a positive neighborhood impact in the area bounded by Broadway and Washington St., east of the river channel. A second approach would be to alter the physical character of the channel by softening the bottom, or greening it by enlarging the channel below the bank (greening and enlarging must be hand in hand to maintain flood control). The third approach combines the first two strategies. It is possible to realize the significant land uses above bank in conjunction with river-oriented habitat and/or park space below bank. Probably the most difficult to achieve due to coordination, time, commitment and imagination, this third approach is the most three dimensional and synergistic. It provides significant access to and from the river, the greatest combination of development and public use, and the most change from existing conditions. As this project moves forward it is important to understand the validity of these three approaches and how they can be accomplished over time. It may be that as some above bank parcels become available they will be transformed with an eye towards future change below bank. Meanwhile, the flood control aspects of the river (including watershed management) would be re-envisioned. George Hargreaves Chaiman of the Department of Landscape Architecture Harvard Graduate School of Design epilogue 156 Changing the physical character of the Los Angeles River is an extreme task, but it is possible. There are several areas of common content that emerge from the students' work such as regional attractions, east/ west connections, habitat development and water cleansing. As discussed, the railyard site is a pivotal agent of change. The transformation of this space could be considered iconic of a new era for the Los Angeles River. The students typically imagined this site as a regional attraction - through remediation of water and/or the creation of habitat, or as a regional development opportunity (public institutions or housing) with smaller green and hydraulic strategies. As one looks up and down the river corridor there are other important and large sites such as this that will become available within the next few decades. These should be looked at together in order to develop a larger coordinated strategy for the Los Angeles River basin. In addition, the student proposals sought to connect the east and west sides of the river either through land uses, connective elements, or both. Transitioning the warehouse and light industrial zones into parks and development space was a common theme. The west side is a growing loft neighborhood while the east is a long established single family community separated from downtown by the river. Whether recreational or habitat-oriented park space, or development and some sort of river access joins the two, the students and stakeholders stressed this connection. A number of student proposals also addressed the establishment of habitat as they re-envisioned the river channel. Examined at the regional scale, this section of the river is on the flyway. If it is to be part of the wildlife matrix, wetlands and water bodies must be reintroduced. Since water is scarce, many proposals link water remediation to habitat. As the river is reenvisioned it is important to solve any pollutant issues on-site, thereby preventing contaminants from continuing to flow downstream as well as firmly establishing policies that reduce run-off within the regional watershed. The students have shown that this section of the Los Angeles River is ripe for creative and imaginative proposals that bring the river back to the city and the neighborhoods as a valuable resource. The river can become important to the people who live near it and those within the region - it can be a newfound icon. Thanks to the Friends of the Los Angeles River and the Santa Monica Mountains Conservancy there is leadership within the community. This project is big. It is important. It is ready for the next imaginative step. epilogue 157