Assessment of Solar Photovoltaic Water Pumping of WASA Tube Wells for Irrigation in Quetta Valley Aquifer

This paper investigates the impact of tube wells on the discharge and water table of the Quetta Valley aquifer and conducts a financial analysis of the solar photovoltaic water pumping system (SPVWP) in comparison with a typical pumping system for the Water and Sanitation Agency of Quetta's (WASA) tube wells. Quetta Valley is dependent on groundwater as surface resources are on decline and unpredictable. The population of this city has exponentially increased from 0.26 million in 1975 to 2.2 million in 2017 which has put a lot of pressure on the groundwater aquifer by installing more than 500 large capacity tube wells by WASA and Public Health Engineering (PHE) departments in addition to thousands of low-capacity private tube wells. The unprecedented running of these wells has resulted in drying of the historical Karez system, agricultural activities, and the sharp increase in power tariffs. There are 423 tube wells in operation installed by WASA in addition to PHE, Irrigation and Military Engineering Services (MES), which covers 60% of the city's water demand. The results will be beneficial for organizations and positively impact the operation of these wells to meet public water demand. For the two zones, i.e., Zarghoon and Chiltan in Quetta Valley, recommendations are given for improved water management.