13 January 2005
Good rains have been recorded during the last two days in the old year and
have continued since the onset of the New Year.
The full effect of the rain on some of our major dams is still not evident
because some of the waters are still in the rivers on its way to these dams. As
of Monday, 9 January 2006, the average level of all Department of Water Affairs
and Forestry (DWAF) dams have risen only by 0.8% (from 55.9% to 56.7%), but the
situation should improve by at least 3% during the next week.
There are still 55 of a total of 146 dams monitored by DWAF of which the dam
level is below 50% and more than 30 of these dams have less than 30% water
left. Except for very small dams, not many of these dams have improved
dramatically, in spite of the very good rains.
This is a good indication of the very dry state of the catchments as most of
the rain was simply absorbed into the soil. The low intensity of the rain in
many cases also contributed to the high absorption.
This will have a very positive affect on the ground water table giving
relief especially to rural communities, but it would take a while before the
reaction would be visible.
Except for a few much localised flood events in smaller rivers, the only
substantives flood occurred in the Grootdraai Dam and Vaal Dam catchment. Both
these dams are situated on the Vaal River.
On 9 January 2006 flood gates had to be opened at Grootdraai to release
water from the incoming flood which peaked at 1200 m3/s. The maximum release
was kept below 650 m3/s to prevent any inundation of the low lying areas of
Standerton.
A second event occurred as more rain fell in the Grootdraai catchment and
the flood gates had to be opened, this time to 800 m3/s. Together with the
contribution from the intermediate catchment, increased the flow past
Standerton to 850 m3/s. This is still a safe release for the town.
All these waters plus runoff from the area between Grootdraai up to Vaal Dam
is currently raising the level within Vaal Dam, from an initial 34% to 54% on
13 January 2006 and the prospects are that the level could exceed 60% within
the next five days. The inflow peaked on 11 January 2006 at 2300 m3/s.
Bloemhof Dam, which is still further downstream on the Vaal River, will also
benefit by the rains and will rise from a low of 9% a week ago, to more than
30% within the next seven days.
Enquiries:
AMM Muller
Cell: 082 807 4341
Issued by: Department of Water Affairs and Forestry
13 January 2005
