Sustainable ground water withdrawal assessment through pumping test for well field design and hydraulic modeling application using watergems for rural water supply: a case study of shilla village beside the Damodar river

Abstract

This research work presents a comprehensive assessment of the hydrogeological characteristics and the design of a sustainable water supply system for Shilla village, Galsi-1, Purba Bardhaman located beside the Damodar River in West Bengal. The study involves conducting pumping tests to determine key aquifer properties such as transmissivity and storativity, alongside Vertical Electrical Sounding (VES) surveys to delineate subsurface lithology and aquifer geometry. The results indicate a stratified subsurface with significant clay and sand layers, crucial for aquifer characterization and well field design. The pumping tests revealed an average transmissivity 2414 m²/day and storativity of 0.1209, with recuperation tests showing an average transmissivity of 2795 m²/day. Based on these findings, a well field design comprising ten strategically spaced wells, each well having capacity of 800 m³/day, was proposed to meet the water demand without exceeding specified drawdown limits of 2.55m. Mechanical analysis suggested the need for artificial gravel packs around the pumping wells due to the Coefficient of Uniformity (Cu) values ranging from 1.8 to 2.4. Hydraulic modeling using WaterGEMS software enabled the simulation and optimization of the water distribution network, ensuring efficient supply to the target areas. The minimum pressure at the extreme consumer end (J-244) was found to be 8.25m of H2O, exceeding which is within the CPHEEO manual limit ( ≥ 7m of H2O). Projected water demand for Shilla village up to the year 2052 was estimated, guiding the future planning of the water supply scheme. The findings underscore the importance of integrated hydrogeological assessment and advanced hydraulic modeling in developing sustainable water supply systems for rural areas.