1.1 BACKGROUND OF STUDY
.A flood is an overflow of an expanse of water that submerges land Floods are among the most devastating natural disasters in the world, claiming more lives and causing more property damage than any other natural phenomena. In Lagos metropolis, though not leading in terms of claiming lives, flood affects and displaces more people than any other disaster it also causes more damage to properties. At least 20 per cent of the population is at risk from one form of flooding or another (Etuonovbe, 2011).
Iwena (2005) described flooding to be the accumulation of an abnormal large volume of water in an area which has refused to percolate or flow away, it usually occurs when there is heavy rainfall in an area and all the water refuses to sink into the soil but flows on the earth`s surface as floods. When such floods occur in the cities it is referred to as Urban Flooding.
Etuonovbe (2011) stated that flooding may occur when water in the river overflows its banks, or sometimes results from a torrential rainfall due to climate change. It happens without warning but with a surprise package that always delivers to unprepared community like the ones in the Lagos metropolis i.e Makoko, Ikorodu, Victoria Island, Ajegunle, Bariga and so on. In Makoko, flood disaster has been perilous to people and communities. Recently and other parts of lagos state have been affected by flooding, chasing the inhabitants away and retarding commercial activities. It has shattered both the built-environment and underdeveloped areas. It has claimed lives, and thousands of properties got lost or destroyed due to its occurrences. One prominent feature about it is that flooding does not discriminate, but marginalizes whosoever refuses to prepare for its occurrence (UNHabitat, 2008).There are factors of flooding depending on locality.