A NOTE ON INTERANNUAL RAINFALL VARIABILITY AND WATER DEMAND IN THE JOHANNESBURG REGION

The demand for water in the Johannesburg area is strongly influenced b y inter-annual rainfall variability mainly toward the end of the rainf all season. During the winter and early part of the rainfall season, w ater demand is largely unaffected by rainfall variability. The relatio nship is strongest from about February to May and in November, when wa ter demand decreases with both rainfall and number of rain days. The d evelopment of skilful seasonal rainfall forecasts could provide useful indications of expected water consumption in the Johannesburg region.