Water quality management by enhancing assimilation capacity with flow augmentation: a case study for the Yamuna River, Delhi

This paper aims to assess the requirement of load reductions and flow augmentation to enhance the assimilation yield of the Yamuna River, Delhi. The framework QUAL2kw was used to predict river quality. The model was calibrated and confirmed in critical flow conditions of pre-monsoon periods. Three strategies were established for varying pollutant loads. The dissolved oxygen (DO) concentration was predicted with changing biochemical oxygen demand (BOD) and chemical oxygen demand (COD) loads. The 16 outfalling drains were considered pollutant sources between the 22 km stretch of the river. Four cases were studied with varying flow augmentation at upstream and varying load. It has been observed that with 80 cumecs of upstream flow, the reach can assimilate 31.33 TPD of BOD and 142.85 TPD of COD load, maintaining the desired level of DO (=4 mg/l) and BOD (=3 mg/l).