BFP06. Water-use accounts in CPWF basins: Simple water-use accounting of the Limpopo Basin.
This paper applies the principles of water-use accounts to the Limpopo River basin in southern Africa. The Limpopo rises in South Africa and flows northwest along the border with Botswana and Zimbabwe before crossing Mozambique to enter the Indian Ocean. Rainfall in the basin varies between 200 and 1500 mm, with much of the northern and western parts receiving less than 500 mm. Rainfall is strongly seasonal, with a short rainy season leading to negligible river flows in the dry season.
Net runoff from the basin is about 2% of the water received as precipitation. Grassland covers 57% of the Basin and uses about 53% of the available water. Rainfed agriculture covers 40% of the Basin and uses 40% of available water. The area of irrigated agriculture is small and uses less than 1% of the available water. Although industrial water use in the upper Oliphants River is important locally, it accounts for only 0.3% of the total available water.
Climate change, using an assumed decrease of 7.5% in precipitation overall, would reduce discharge of the Basin by 25%. A proposed dam in Mozambique to irrigated 1000 sq km would likely reduce downstream flows in normal years, but would probably not prevent floods like those of 2000.
CPWF Working Paper: Basin Focal Projectseries, BFP06. Colombo, Sri Lanka: The CGIAR Challenge Program on Water and Food. 22 pp.