Drainase

The main issues with drain water in Khulna, Bangladesh, include contamination, a lack of infrastructure, and sensitivity to seasonal changes. This review paper discusses the different causes of drain water pollution, such as inadequate drainage systems and poor waste disposal procedures, as well as the effects of this pollution on the environment, such as waterlogging and ecosystem contamination. The length of the current drainage systems in Khulna is roughly 528.120 km, with primary drains covering 175.43 km (33.22%), secondary drains spanning 150.45 km (28.49%), and tertiary drains spanning 202.24 km (38.29%). 291.230 km (55.14%) of these are pucca, or wellconstructed drains, 51.790 km (9.81%) are semi-pucca, and 185.10 km (35.05%) are kutcha, or earthen drains. However, research on drainage density in 31 wards revealed that wards 23 and 31 had the highest and lowest drainage densities, respectively, of 33.88 km/km2 and 3.06 km/km2, with a citywide average of 11.79 km/km2. 51 primary outflow sites make up the drainage system in Khulna City, which is drained by the Bhairab, Rupsha, Mayur, and Gallamari rivers. Additionally, according to recent research by the Khulna Development Authority (KDA), just 33% of city residents have access to some type of drainage facility close to their homes, leaving roughly 67% without designed drainage systems. The drainage systems at KCC have been discovered to need further upkeep and cleaning. This paper intends to offer useful insights for policymakers, researchers, and environmentalists working toward a sustainable and healthy urban environment in Khulna by illuminating the amount of drain water pollution and outlining numerous alternatives.