One of the main experimental watersheds relevant for Managed Aquifer Recharge (MAR) studies in WP2 is located around the town of Maheshwaram. With a total area of 54 km2, it is located in a semi-arid hard-rock context typical of the entire region where the saprolite layer (10-20 m thick) is usually unsaturated. It is a watershed with a high density of groundwater production wells (>700) mostly for paddy irrigation; changes in land use have occurred since 2006 because of the new Hyderabad international airport located less than 10 km away. It is expected to become a peri-urban area within the coming years as significant housing projects are planned. MAR has been implemented throughout the watershed in the form of percolation tanks, check dams, defunct dugwells, etc. over the last decade.

Intensive groundwater exploitation for irrigation has resulted in aquifer over-exploitation and deterioration of groundwater quality (fluoride above maximum permissible limit of 1.5 mg/L, salinisation and agricultural inputs). MAR is an attractive concept for groundwater augmentation and enhanced groundwater quality nearby wells exploited for domestic uses. The objective of the tasks in WP2 for the case study site in Maheshwaram is to investigate the potential of percolation tanks to enhance recharge and groundwater quality in the underlying over-exploited hard-rock aquifer by implementing a monitoring strategy for groundwater levels and quality, conducting hydrogeochemical analyses and investigating the hydrodynamics with the support of a conceptual groundwater balance model developed in cooperation with WP5.

Geological map of Maheshwaram watershed
Geological map of Maheshwaram watershed. Main MAR (percolation tanks and defunct dugwells) structures are indicated in blue Green areas.