Sediment redistribution in Ilorin, Nigeria

Summary

Ilorin is a city in which there is a great deal of construction work currently taking place. Vast amounts of sand and gravel are transported from the suburbs into the city daily. Lack of planning has led to a misuse of the land, the consequence of which is sediment redistribution. Road surfaces and drains have become buried under sediment. There appears to be a fundamental conflict between the natural drainage network and the artificial drainage system.

Over 90 percent of the people in Ilorin are aware of the problem, but they have not, as yet, urged any action, probably because the consequences of sediment redistribution and deposition are comparatively less disastrous than other natural hazards. However, water treatment costs are increasing and regular street maintenance is becoming impossible. There is a general deterioration of the city environment. The Ilorin ‘sediment pollution’ has even resulted in traffic accidents, especially at T-junctions.

This paper examines some of the sources and causes of the sediment and proposes possible solutions to the problem.