Sustainable Resource Management: WESTERN CAPE WATER SITUATION | DECEMBER 2011
Situation as at 12 December 2011
| Dam | Capacity | 01-May-11 | 05-Dec-11 | Increase (+) from 1 May '11 | ||
| Storage | % | Storage | % | Mcm | ||
| Steenbras Upper | 31.7 | 20 | 63 | 30 | 95 | 10 |
| Steenbras Lower |
33.5 | 14 | 42 | 26 | 78 | 12 |
| Wemmershoek | 58.6 | 31 | 53 | 45 | 77 | 14 |
| Voëlvlei | 165.4 | 84 | 51 | 133 | 80 | 49 |
| Theewaterskloof | 480.2 | 244 | 51 | 376 | 78 | 132 |
| Berg River Dam | 130 | 74 | 57 | 121 | 93 | 47 |
| Total including BRD | 899.4 | 467 | 52 | 731 | 81 | 264 |
Rainfall recorded at the Theewaterskloof, Voelvlei, Wemmershoek, Steenbras and Berg River Dams in the last week was 1, 2, 4, 4 and 8 mm respectively. The gross system storage has decreased from 748 million m3 to 731 million m3 (81%). The total increase since the 1st May 2011 is 264 million m3.
According to both the South African Weather Service (SAWS) and the NMI (Norwegian Meteorological Institute) there is a fair (30-60%) chance between 5 and 15 mm of rainfall over the South Western Cape Water Supply Area on Tuesday/Wednesday (13th/14th December).
Situation as at 5 December 2011
| Dam | Capacity | 01-May-11 | 05-Dec-11 | Increase (+) from 1 May '11 | ||
| Storage | % | Storage | % | Mcm | ||
| Steenbras Upper | 31.7 | 20 | 63 | 31 | 98 | 11 |
| Steenbras Lower |
33.5 | 14 | 42 | 26 | 78 | 12 |
| Wemmershoek | 58.6 | 31 | 53 | 46 | 78 | 15 |
| Voëlvlei | 165.4 | 84 | 51 | 138 | 83 | 54 |
| Theewaterskloof | 480.2 | 244 | 51 | 385 | 80 | 141 |
| Berg River Dam | 130 | 74 | 57 | 122 | 94 | 48 |
| Total including BRD | 899.4 | 467 | 52 | 748 | 83 | 281 |
Of the major dams supplying the Western Cape Water Supply area only Theewaterskloof Dam received some rainfall (2.5mm). The gross system storage has decreased from 758 million m3 to 748 million m3 (82%). The total increase since the 1st May 2011 is 281 million m3.
Both SAWS (South African Weather Service) and the NMI ( Norwegian Meteorological service) forecast a slight chance of widespread light rainfall (0-5mm) on Wednesday / Thursday (7th/8th December). At present the NMI, with their longer forecast period, suggest that there may also be a slight chance of rainfall next Tuesday / Wednesday (13th/14th December) but one would have to confirm this closer to the time.
