Impact Assessment of Artificial Recharge Structures on Kakatiya University Campus, Warangal Urban District, Telangana

Abstract

The artificial recharge structures (ARS) project was taken up on Kakatiya University campus, Warangal urban district, Telangana state with the dual purpose of meeting the growing demand for water supply on campus and to demonstrate the benefits of artificial recharge to the students and society at large. Different types of site-specific recharge structures were developed in tune with the local hydrogeological conditions. 9 check dams, 2 mini-percolation tanks (MPT), 2 percolation tanks, 1 Gabion structure, 1 farm pond, and a series of continuous contour trenches, staggered contour trenches, and 69 rooftop rainwater harvesting structures at 19 different buildings were constructed. These structures together contributed 27.62 ham of water to the local aquifer in the year 2013; the estimate is substantiated by applying GEC methodology-1997. The mean water levels have risen by 8.41 m between 2012 and 2014 and a rising trend of 3.05 m is displayed on an average in hydrographs of the observed wells. Efficacy of ARS was visible in terms of feeble adverse effect in 2014 (the change in the head was −0.71 m) despite a deficit rainfall of 42%. Water chemistry displayed a mixed response to induced recharge; cation content was reduced in some samples whereas anions were added in about half of the tested samples. Hydrological properties, together with solute load and absorption-desorption capacity of percolating water, might have led to hydrochemical variability. The locations and appropriate designs enabled to harvest the rainwater in the most effective way leading to a net rise in depth of water levels by 3.24 m and 2.30 m between pre-monsoon of 2012–2013 and 2013–14 respectively. In the post-monsoon season, it was 1.68 m and −3.22 m for the same years (in the 2014 monsoon the area received 171 mm deficit rainfall). Despite poor rainfall in 2014, due to the completion of the ARS scheme, the bore wells yields stabilized at 4.07 lakh liters/day which was about 40% more than the pre-project year, May 2012.