Hydroelectric dams have markedly altered the extensive floodplain of Zambia's Kafue River Flats. Before the dams were built in the 1970s, some 6,000 km2 of floodplain were under water for several months each year, permitting a dense growth of grasses and forbs that supported large populations of ungulates and waterbirds. Now a dam at the lower end of the Flats has permanently inundated parts of the floodplain, and a dam at the upper end has reduced the seasonal flooding, so that much of the floodplain is now probably permanently dry. When the Flats was revisited in 1983, the effect of the dams was obscured by the effects of drought, hunting, and human use.
In 1983, plant growth in most places was much less luxuriant than it had been before impoundment. Bird populations seemed much smaller than formerly, and populations of at least some ungulates had declined. The most abundant ungulate, the Lechwe (Kobus leche), is reported to have declined by about half in the last eight years.