Managed aquifer recharge in Atlantis, South Africa

Abstract

The town of Atlantis with a population exceeding 60,000 is located 50 km north of the centre of the City of Cape Town and presently forms part of the metropolitan area. Previously, the area resorted under the authority of the Cape Divisional Council and in 1976, the new Atlantis development was declared a National Growth Point, under the government’s “decentralisation initiative”. As it was planned to become an industrial growth point various incentives were introduced for attracting industries to the area. As the west coast is semiarid, the importation of surface water from the Berg River system, located some 70km distant, was planned as the permanent water supply source. However, in 1972 the Department of Water Affairs and Forestry started developing local groundwater as an interim measure allowing for the postponement of the pipeline construction. In the early phases of development all water supply was provided by the perennial springs at Silwerstroom. These produced an average flow of about 1 x 106 m3 per year. A weir was constructed to capture the spring flow in a small dam, from which it was pumped to the growing town. Subsequently two wellfields were developed and over the next 25 years the local groundwater proved itself as a sustainable water resource providing the bulk of the water demand. Only in 2000 limited augmentation of the water supply by surface water was introduced via an alternative route.