In the First Edition of the National Water Resource Strategy (NWRS1) of 2004 the total volume of water available from the river systems in South Africa on a reliable basis for 2025 was estimated at 14 166 million m3/a.
The total water requirements for 2025 base and high scenario was estimated at 14 230 million m3/a and 16 814 million m3/a respectively. The amount of water that could potentially be available for development in the year 2025 was estimated at 5 410 million m3/a. This surplus amount is however only available in some catchments throughout the country. This analysis was done considering a projected population of 54 million and economic growth trends at the time.