Water resources in the Klein Karoo: the challenge of sustainable development in a water-scarce area

Abstract

The Klein Karoo is situated in the Western Cape, South Africa, and is characterised by low rainfall (100 - 450 mm yr ^{- 1}). The Klein Karoo is situated in the primary catchment of the Gouritz River. The mean annual runoff (MAR) for the three major tributaries of the Gouritz River arising in or feeding the Klein Karoo (Touws, Gamka, Olifants) is 540 Mm³ yr ^{- 1}. Groundwater recharge in the three Klein Karoo catchments is ±257 Mm³ yr ^{- 1}, but only a portion of this reaches the rivers. The very variable flows result in low 1:50 year yield of 161 Mm³ (30% of MAR). The current demand for water in these catchments is 182 Mm³ yr ^{- 1}, which exceeds the yield, and demand is projected to increase between 23% and 150% by 2025. Changes in the approach to water management are required, including improving the efficiency of irrigation and land restoration to improve water infiltration and reduce soil erosion. We believe that it is time to change to a water management approach that is designed to anticipate and manage the inherent variability in water resources in the Klein Karoo, thereby placing the region on a path to sustainable development.