Staff Reporter
HEAVY rainfall is expected in the southern regions over the weekend, while the Zambezi and Okavango rivers continue to rise.
Contingency planning for flood risk mitigation and recovery is to be activated, especially for flood-prone areas as more rains are forecast for this rainy season.
According to the Hydrological Services of Namibia of the Ministry of Agriculture, Water and Land Reform, rainfall performance during the first part of the rainy season was very poor over most parts of the country except for the north-eastern, south-eastern and north-central areas that received above-average rainfall.
Satellite images over the past 72 hours indicate heavy rainfall over Namibia’s central and south-eastern parts.
River flows have been observed in some of the country’s central, southern and west-flowing ephemeral rivers due to heavy rains in their catchments over the past days.
High floods were already observed on the Lower Orange River during the first week of January.
The situation requires very close monitoring and high-level alertness because of possible serious flooding on the Lower Orange River.
The latest update on the situation in the Vaal-Orange system, courtesy of Dr. Dennis Dlamini (DWS South Africa) is that the Vaal, Bloemhof, Gariep and Vanderkloof dams are all above 100%.
The water levels along the Lower Orange River are medium-high and increasing due to the medium-high releases from the Bloemhof Dam and increasing outflow from Vanderkloof Dam.
The flows are forecast to increase significantly starting over the weekend and possibly rising beyond 3200 m³/s by mid next week.
In Namibia, NamWater released water at the Naute and Hardap dams on Friday morning.
These releases and further rainfall development in the Orange-Fish catchment will add to the ongoing flows in the Fish River and high flows in the lowest part of the Lower Orange River downstream of the Fish-Orange confluence.
The Zambezi and Okavango rivers continue to rise.
The Zambezi River at Katima Mulilo recorded 1.29 m while the Okavango River at Rundu recorded 4.14 m Friday morning. The water levels for the two rivers are lower compared to the same period last year. Flows in the Kunene River remain low during this time of the year.
The country’s major dams received significant inflow due to heavy rains and floods in their catchment areas during the past few weeks.
The Neckartal Dam volume stood at 808.42 Mm³ Friday morning, equivalent to 94.3 % of its capacity with an inflow rate of 47.9 m³/s.
The Naute Dam stood at 100.7% on Friday afternoon, and releases have stopped.
The Hardap Dam stood at 72.9% on Friday afternoon, and the release rate was increased to 400m/s at 21:00 from 300m/s at 9:30.
According to NamWater other dam levels are as follows: Swakoppoort 77.2%, Von Bach 46.7%, Friedenau 85.7% and Oanob 75.3%.
