A Feasibility Case Study of Storm and Sewer Drainage Systems of Rajarhat Gopalpur Municipality

Abstract

Drainage systems play a vital role in the framework of any well-functioning society. From a hydraulic design perspective, a drainage network is just the opposite of a water supply distribution network. This study focuses specifically on evaluating and properly designing the existing drainage system which may help the relevant government body in planning, implementing, operating, and maintaining the stormwater drainage systems to solve the problem of wastewater logging like in the study area, along with sustainability that contributes to better service in drainage schemes. According to the results obtained from this study, the existing storm and sewer drainage facility in ward number four of Rajarhat Gopalpur Municipality, West Bengal is observed to be insufficient to transport the peak stormwater discharge during the essential design period. Several drains are found overflowing that cause wastewater-logged flooding and misbalances the day-to-day life of the citizens, especially during the rainy season. The hydraulic analysis for the drainage system had been carried out using SewerGEMS software by dividing the area into seven sub-catchments for better management of the flow of wastewater. From the analysis, it is observed that in some drains, the velocity is very low to negligible in comparison to the self-cleansing velocity. Other parameters such as flow and hydraulic grade line were also computed from the existing network. From the study, a few modifications are advised such as how to achieve a minimum velocity that should be developed in all stormwater-sewer drains so as not to allow any deposition in the drains.