To exploit the groundwater resources for water supply projects in any area needs proper systematic groundwater exploration techniques. This study pertains to providing water supply to an aquaculture project for which systematic groundwater investigations have been taken up in a coastal plain of Nellore district. The research area falls in Venkannapalem of Thottapalli mandal in Nellore district of Seemandra state, India. It is a coastal sedimentary area, about 2 to 3 kms from sea coast. Geological, hydrogeological, geoelectrical investigations and pumping test have been conducted to prospect the groundwater resources. Among the surface geophysical methods, electrical resistivity technique [ERT] is widely used, which is non- invasive and cost effective. 1D VES was carried out to explore the potential phreatic aquifers. A pilot borehole was drilled and electrically logged to delineate the granular and fresh water zones. A tube well has been constructed to a depth of 51m, developed and completed. The yield was reported as 4’’ [276 lpm]. A constant discharge pumping test was done to evaluate the aquifer parameters, transmissivity [T], Storativity [S], hydraulic conductivity [K] by both Jacob’s straight line graphical method and by software program . The values computed by both methods are nearly the same. The T, & K values are 97/90 & 6.4/6.01 respectively. The specific capacity of the aquifer is 683 lpm/ 1.3m dd/ 8 hrs of pumping. Thus the systematic groundwater investigations in coastal plains proved to be successful and fruitful.

Keywords : Phreatic aquifers;1D VES;Electrical well logging; Aquifer parameters.