BATHYMETRIC SURVEY AND VOLUMETRIC ANALYSIS OF ASA DAM FOR SUSTAINABLE WATER RESOURCE MANAGEMENT IN KWARA STATE, NIGERIA

This study presents a bathymetric survey and volumetric analysis of a section of Asa Dam, located approximately 5 km south of Ilorin in Kwara State, Nigeria. The study aimed to generate bathymetric charts and determine the reservoir’s volume to support effective water resource management. Field data acquisition involved establishing a vertical datum using a Hi- target Differential GPS receiver, water level measurement was carried out using an automatic level, and depth sounding using the Garmin EchoMAP 50dv echo sounder mounted on a survey boat. The collected data were processed and analyzed using a combination of Garmin Homeport, Surfer, AutoCAD, Esurvey CAD, Franson coordinate converter, and ArcGIS software. Different software was used in computing and cross-validating the reservoir volume, yielding values of approximately 2,074,442.70 m³, 2,024,444.16 m³, and 2,075,191.45 m³. Generated outputs include bathymetric charts, contour maps, and digital elevation models, revealing an irregular underwater topography. The study revealed the importance of regular bathymetric monitoring for sustainable reservoir management and future development planning. This study provides critical baseline data essential for decision-making and ecological preservation in Asa Dam.