Studies on the potentials of the Opeki River Dam for water supply and irrigation

Abstract

Effective management of existing water reservoirs has been identified as profitable strategy to solving the challenge of providing adequate water for domestic and irrigation uses. The Opeki River Dam is a medium size dam with a maximum active storage capacity of 2.1million cubic metre (mcm) and a guaranteed maximum all year round active storage of 1.78mcm. This in addition to supplying the 2.72million litre/day (ml/day) raw water to the treatment plant can also sustain a cultivable command area (CCA) of between 200ha of maize or melon or 175ha of tomato or a feasible combination of the three (3) crops. At present, the treatment plant capacity is inadequate for the intended population and needs urgent expansion to meet the future demand of 11.6ml/day and 17.6ml/day by year 2010 and 2025 respectively. Whereas the water supply is primary, the secondary objective, which is irrigation within the catchment area, can be substantially achieved if effective management of the reservoir capacity is focussed upon. However, in order to cultivate 50% of the CCA of the Eruwa Farm Settlement of 2500ha, an expansion of the reservoir to provide 12.0mcm will be necessary. The quality of the raw water was also found to be acceptable for crop production based on the FAO (1985) standard on irrigation water.

Keywords: Opeki River, dam, water supply, irrigation

Moor Journal of Agricultural Research Vol. 5(1) 2004: 74-81