Quantitative assessment of groundwater resource potential in a coalfield of Damodar River Basin India

The present study was carried out for the quantitative assessment of groundwater resource potentials in East Bokaro Coalfield of Damodar River Basin. The rise and fall of groundwater table is closely related to the hydro-meteorological conditions, water level, landform, geology and morphological factors. Average annual rainfall for the entire period of 35 years is 1366 mm in which annual maximum rainfall was 2544 mm in the year 2001 and minimum was 733 mm in the year 2004. The fluctuation of groundwater level ranged between 0.15 and 2.87 mbgl in the study area. Rainfall is the main source to replenish the groundwater by percolation through deep soil zones. Besides rainfall, the mine water discharges from the local mining areas and existing water bodies including water logged in abundant mine quarries. Mine water also contributed to the groundwater recharge as return flow. The study area is highly disturbed and the permeabilities of individual geological units are spatially variable and depend on lithology, fracturing and attenuation with depth. The total annual replenishable recharge was calculated to be 48.5 million m³/year and net annual groundwater availability was estimated to be 13.7 million m³ by rainfall infiltration method. The stage of groundwater development was calculated as per GEC-1997 guideline, which falls under the safe category (i.e., 67%). But water resource conservation for sustainable water management is urgently required in the study area.