Rainwater harvesting is one of the promising ways of supplementing the
surface and underground scarce water resources in areas where existing water supply
system is inadequate to meet demand. Rainwater harvesting is one of the measure for
reducing impact of climate change on water supplies. Abeokuta has a mean annual
rainfall of 1,156 mm which makes rainwater harvesting ideal. Intra annual variability
lies betwen 0.7 and 1.0 while the inter annual variability was 0.2. Annually 74.0 m3
of rainwater can be harvested per household. Estimated annual water demand
for flushing, laundry and flushing were 21.6 and 29.4 m3 respectively. Harvested
rainwater in Abeokuta can satisfy household monthly water demand for WC flushing
and laundry except for November, December, January and February. The excess
rainwater stored in September and October is sufficient to supplement the short
fall in the dry months provided there is adequate storage.Water savings potential
is highest in June and September which is the two rainfall peak period in Southwest
Nigeria