Zambezi River Basin

The delivery of safe drinkingwater inmost of the basin’s urban areas is hindered by old and inadequate infrastructure.

Some wetlands in the Zambezi River Basin

are receding due to reduced flows caused by

droughts and water extraction. Other wetlands

are increasingly being infested by aquatic weeds

while still others are exposed to persistent

organic pollutants such as DDT, the pesticide

dichlorodiphenyltrichloroethane. Some wetlands

have also been inundated with water as a result

of dam construction. Additional threats to

wetlands include overexploitation of resources,

uncontrolled fires, pollution and deforestation.

These threats alter wetlands, causing habitat

change and species loss (Chenje 2000).

The Lower Shire River in Malawi, the Zambezi

Delta in Mozambique, the Kwando/Linyanti/

Chobe system draining down the Caprivi in

Namibia, and the Kafue flood plains in Zambia

are the most environmentally sensitive wetlands

in the basin (Bethune 1999).

The Kafue Flats

The Kafue Flats in southern Zambia are an

extensive floodplain system that lies in the

middle Kafue River. The floodplain covers an area

of approximately 6 500 sq km, and is sandwiched

between two large dams, which are 270 km

apart (Mumba and Thompson 2005). The dams

have altered the hydrological regime of the

system, with backwater from the Kafue Gorge

Dam downstream and releases from the Itezhi-

Tezhi Dam upstream creating a permanently

flooded area in the floodplain. The hydrological

and vegetation changes have affected the

habitat for important wildlife communities

including the endemic lechwe antelope, (

Kobus

lechwe kafuensis

). The other dramatic change

in vegetation is the colonization of parts of the

floodplain by the invasive alien plant,

Mimosa

pigra

(Mumba and Thompson 2005).

The Kafue River and its floodplains are heavily

utilized and highly industrialized, and subjected

to pollution from mining, industry, agriculture

and municipalities. A joint study by the

University of Zambia and the Swedish Lulea

University of Technology shows high levels of

heavy metals, particularly copper, in the Kafue

River near the Copperbelt area. The floodplain

also suffers from heavy grazing and overfishing

(SADC and SARDC 2008).

The Zambezi Delta

Water regulation from Cahora Bassa dam has

substantially reduced the Zambezi Delta wetland

productivity and even offshore shrimp catches in

Mozambique (Chenje 2000). Saltwater intrusion

has become a problem in the delta as a result of

reduced freshwater flows and the lack of regular

substantial seasonal floods. Irregular floods in the

delta are associated with cyclonic rainfall along

the Mozambique coast.

Wetlands