Evaluation of groundwater balance - A case study of mona drainage basin

Determination of Water balance in the irrigated areas is of prime importance for managing the irrigation and drainage system. Mona Drainage Basin of Chaj Doab is located between the right bank of Lower Jhelum Canal and the left bank of River Jhelum. This area has a pivotal role in the agricultural economy of the Pakistan because of its strong infrastructure for irrigated agriculture. The main objective of this study was to determine the water balance in the selected area and suggest measures for the sustainability of irrigated agriculture. Average annual water balance has been calculated for the study area. Recharge and discharge components have been quantified. Recharge components include rainfall, seepage from irrigation canals and watercourses, deep percolation from fields and seepage and deep percolation from tube well supplies. Discharge components include tube well pump age and evaporation from waterlogged areas. It has been observed that recharge to groundwater is less as compared to discharge in the area. Due to the increased demand for irrigation and domestic water, the use of groundwater has been increased. To meet the increased irrigation requirements, farmers have installed private tube wells in the area. Historic water table data indicate a gradual drop of water table in the area. Water table is being depleted due to excessive pumping of groundwater. If water table is allowed to drop as such, availability of groundwater for the next generation will become difficult. For the sustainability of irrigated agriculture canal supplies are to be increased. This will also help reduce demand for groundwater use. A groundwater regulatory framework needs be developed for its sustainable use.