Groundwater Resource Assessment by Hydraulic Properties Determination for Sustainable Planning and Development in Central Part of Ondo State, Nigeria

Abstract

Determination of hydraulic properties for groundwater resources assessment in central area of Ondo State was carried out using pumping test, with sessions which lasted for a period of 7-12 hours for a total of 76 boreholes. The installation depths of the boreholes vary from 8.5 m to 49.7 m. The thickness of the aquifer units/screen length is in between 2.3 – 26 m and average (avg.) of 7.7 m. The yield  capacity of the aquifer units varies between 17.28 (granite) – 110.59 m³/d (migmatite). The hydraulic conductivity calculated for the area  ranges between 0.1382 – 48.1210 m/d (avg. 4.5487 m/d). The values of transmissivity derived from the area range between 2.4705 –  221.3568 m²/d (avg. 28.1690 m²/d). The storage coefficient or storativity calculated for all the aquifer units in the study area is fairly  uniform and ranges from 0.000069 to 0.007496, and an (avg. 0.000974). Only 40% of the study area is characterized by good aquiferous  units based on their hydraulics properties, which is prolific for groundwater exploitation and development. Even though an average yield  value of 81 m³/d was obtained, suggestive of fair water bearing unit, capable of providing a reasonable satisfying and quantifiable  amount of water for domestic uses.