THE DESIGN OF AN UNDERGROUND STORAGE SYSTEM FOR RAINWATER HARVESTING IN IBADAN METROPOLIS, NIGERIA

Abstract

With vastly increasing population concentration in urban areas of Nigeria, water availability has already caused an intractable problem, whose solution has to involve harnessing and storing water from all sources for continual use. This work is on designing a rainwater storage system for use in individual homes in Ibadan, Oyo State, Nigeria.

Inputs to the design are rainfall data for 1980 to 2003 from which the theoretical rainwater quantity harvestable each month was calculated. Water demand per household of eight persons was computed for use in the design. Platting the graphs of the cumulative mean monthly rainfall and of uniform monthly water demand, the minimum capacity of water storage tank to meet the demand was obtained.

The size of the storage tank and various forces acting on it were found to depend on the roof type and roof plan area.