The influences of land use and sanitation infrastructure on flooding in Kumasi, Ghana

Each year during the rainy seasons, the Ghanaian media is dominated by banner headlines of flooded urban landscapes along with emergency response teams doling out relief items to the victims. However, when the rains subside and the floods are no longer newsworthy, the key stakeholders return to their normal duties only to await the next cycle of rains with bated breath. Based on the analyses of secondary and fieldwork data, the paper found no significant change in recent rainfall patterns that could account for the city's flood problems. Rather, the impervious surfaces created through the removal of wetlands, riparian lands and urban vegetation, along with deposits of sediments and domestic wastes into streams and drains, have combined to slow down the velocity of stormwater flows and allowing it to disperse into the surrounding built up areas in lower terrains. The paper recommends the construction of modern city-wide sewerage systems to cope up with the current and predicted rainfall patterns, complemented by non-structural approaches including the protection of wetlands and urban vegetation to reduce the amount of storm water flows. Planners should anticipate and project future land use demands to cater emerging activities such as LPG stations which currently take sites in open space or flood ways and manage and direct physical development into low risk locations. Other measures would include the consideration of free domestic waste collection systems, mandatory flood insurance schemes on properties, with premiums assessed based on site risks, the development of early warning systems to minimize the effects of floods.