Assessment of Water Surcharge Conditions in an Urban Area Using SEWERGEMS: A Case Study

The most frequent issues with combined sewer distribution systems in urban areas are the ones related to water surcharges. Rapid urbanization leading to an increase in impervious areas, high-intensity rainfall, and clogging of drains due to improper maintenance of sewer systems are the most common causes of surcharge. The main objective of the study is to measure and assess the overflow conditions and locate the potential flood-effected areas in a part of Pragathi Nagar of Hyderabad city, considering the existing sewer drainage system and with the inclusion of Low Impact Development (LID) techniques. To model the scenario for the study area, a computational SEWERGEMS was developed. SEWERGEMS model was developed with and without consideration of LID approaches for various design rainfall intensities for 2-, 5-, 10-, and 30-year return periods. The outcomes implied the effectiveness of the computational model in explaining multiple scenarios and can support the municipal authorities in effectively managing the combined sewer distribution network.