Optimizing operational strategies of scavenger wells in lower Indus Basin of Pakistan

In the lower Indus Basin of Pakistan, where rainfall is low and water use is high, more than 350 scavenger wells were installed under the left bank outfall drain stage-1 (LBOD-1) with a capital cost of US$ 12.75 million to provide drainage and to recover fresh groundwater mainly for irrigation purposes. This paper highlights the environmental issues in the pumping and disposal of saline groundwater for sustainability of scavenger wells. In this paper, the hydraulic performance of two scavenger wells (PSW1A and PSW2) representing different hydro-geological conditions in the lower Indus Basin was evaluated using two numerical models (MODFLOW and MT3D), and changes in the operational strategies of such wells for the concerned hydro-geological conditions have been recommended.