The Department of Water Affairs is warning of dangerously high water levels in the Modder River Riet River and Lower Orange River due to the heavy rainfall particularly in the Bloemfontein area. The Modder River is north of Bloemfontein and the Riet River is just South of that city.
Heavy rains over the past 24 hours in most part of the country have also caused levels in the four major dams to rise significantly. At the Orange- Vaal River confluence at Katlani in the Northern Cape the discharge is 450 m3/s ( cubic meters per second) the flow is expected to peak at 3100 m3/s by the weekend.
In the town of Upington the flow is presently at 430 m3/s to peak at 2900 m3/s by early next week, it is predicted that this flood level will be approximately two meters lower than the flood level earlier this year.
At the same time the capacity of the Vaal Dam is currently at 96%, the inflow is 67 m3/s, while the outflow is 15 m3/s. At the Bloemhof Dam the capacity is currently at 101% and is expected to increase to 103% by Tuesday, 13 June 2011.
The Gariep Dam, is currently at 102% the inflow peak is 3000 m3/s, the outflow is 400 m3/s. The Vanderkloof Dam stands at 101% full, the inflow is 540 m3/s while the outflow is 400 m3/s.
High flows of 1130 m3/s were recorded at Modder River at Glen yesterday these flows have however subsided to 850 m3/s, the capacity of Krugersdrift Dam is 148% and it is expected to peak at 156% today.
Of further significance is the capacity of Kalkfontein Dam which is 144 % full, and is expected to peak at 147 % today, the inflow is 4000 m3/s, ( cubic meters per second) with an outflow of 3000 m3/s to peak at 3600 m3/s this afternoon. The return period of the Kalkfontein Dam inflow peak is more than 100 years. The flow in the Riet River downstream of the confluence with the Modder River will be approximately 3000 m3/s.
