Hydraulic Modelling and Capacity Optimization of The Yawal Municipal Council Sanitary Sewer Network.

Rapid urbanization in small to medium Indian towns has placed mounting stress on existing sanitary infrastructure, frequently built without long-term hydraulic planning. Yawal Municipal Council in Maharashtra presents a representative case: its sewer network suffers from undersized conduits, irregular flow distribution, infiltration/inflow (I/I) intrusions and capacity deficits attributable to decades of ad hoc expansion. This study undertakes a systematic hydraulic assessment and capacity optimization of that network with the objective of restoring reliable, self-cleansing flow conditions across all design horizons. Ward wise population forecasts and sewage generation estimates were derived using CPHEEO-prescribed norms, with three projection stages (2028, 2043 and 2058) establishing the hydraulic loading envelope. Bentley Sewer GEMS was employed to build and calibrate a network model that replicates observed flow behaviour, while QGIS provided the geospatial framework for network delineation, manhole georeferencing and catchment boundary mapping. Model diagnostics pinpointed conduits prone to surcharging and sections with sub-critical self-cleansing velocities. Targeted remediation measures—pipe upsizing, slope correction and network realignment—were evaluated through successive simulation runs and the resulting optimized configuration confirmed hydraulic compliance under ultimate-stage loading. The findings demonstrate that an integrated Sewer GEMS–QGIS workflow, anchored in CPHEEO design standards, offers a replicable and cost-effective methodology for upgrading sanitation infrastructure in growing Indian municipalities.