Kouga Dam

About Kouga Dam

The dam is a double curvature arch dam 82 m high with a storage capacity of 128,7 million m3. Provision was made in the design to allow for a future raising of the water 1ev by some 15,2 m. The construction of the wall marked the beginning of an era of double curvature arch dams in South Africa. Besides the normal central overspill section, flood-control sluice gates with chute spillways were provided on the left flank.

The Kouga Dam and the main canal supply water for both irrigation and urban use; the branch canals are used mainly for irrigation and the Loerie Dam for urban water supply only. Water is supplied to the Port Elizabeth Municipality's purification works at the Loerie Dam site by means of an outlet control tower and tunnel.

From the Kouga Dam, irrigation water is supplied by means of the canal and pipeline system to 7400 ha of scheduled ground. Every irrigator is supplied with at least one draw-off with a self­registertng meter, which he himself can operate according to his needs, up to a mamum Iimit of 8000 m3 per ha per year.

The Kouga Dam was also built to serve as a flood-control dam for floods originating from the catchment area of the Kouga Rtver and to decrease the effects of these floods in the lower Gamtoos area.

Gamtoos Valley downstream of the dam, consists of alluvial deposits of the Ultenhage Series composed of round pebbles, shales and clays, forming near-vertical cliffs of conglomerate. Typical vegetation up against the slopes consists of succulents such as elephant's food, candelabra trees and aloes forming dense, Impenetrable thickets. Dense thorn-trees, yellow wood, wild olive, sneeze-wood, wild fig and many other trees and tall bush grow on the plains and along the beds of the tributaries.