Regions warned about floods
Rivers in Windhoek were in flood recently due to localised high intensity thunderstorms which caused damage to houses and road infrastructure, a report said.
15 January 2021 | Disasters
Contingency planning for flood mitigation and recovery must be activated in the Omusati, Oshana, Ohangwena, Kunene, Khomas, Omaheke and //Karas regions, the agriculture ministry’s hydrological services has warned.
In its daily flood bulletin, the department said communities living in flood-prone areas must take precautionary measures.
The Neckartal Dam already reached more than 50% capacity by yesterday morning, which translates to about 428.5 million cubic metres of water.
The dam, which has a storage capacity of 857 million cubic metres, was 54.08% full at 06:00 yesterday morning, with an inflow rate of 702 cubic metres per second.
An inflow of more than 15.4 million cubic metres was recorded into the dam since Monday.
Unusually heavy rains
According to the flood bulletin, unusually heavy rains occurred in the beginning of January and are continuing across the northern, central, north-eastern, eastern and southern parts of Namibia.
“This resulted in heavy localised flooding in catchments areas.”
Meanwhile, it said the heavy rains and floods recently experienced have seen some of the country’s major reservoirs receiving significant inflow.
“Especially the central and southern dams such as the Naute, Hardap and Neckartal dams received significant inflow and repeated releases were performed at Naute and to keep the Hardap Dam at the 70% operational supply.”
The level of the Hardap Dam stood at 70.5% yesterday morning, which translates to 198.615 million cubic metres of water.
Releases at the dam are still continuing at 500 cubic metres per second. The inflow into the dam was at a rate of 462 cubic metres per second.
An inflow of 9.411 million cubic metres of water was recorded in the dam since Monday.
The Naute Dam was 102.5% full yesterday morning with releases also ongoing at the dam at a rate of 200 cubic metres per second. The inflow into the dam was 130 cubic metres per second. Since Monday, the inflow into the dam was recorded as 5.3 million cubic metres.
Moreover, two valves were opened yesterday morning at the Oanob Dam reached 103% capacity and overflowed.
The hydrological services said rivers in the southern and central parts of the country “came down in flood with raging torrents of water”.
The floods caused damage to properties, roads and agriculture infrastructure, it said.
“Most of the normally dry ephemeral rivers in the interior of the country such as the Fish River had major and repeated floods.”
Floods also occurred in the Khan, Kuiseb, Swakop, Omatako, Ondekaremba, Grass and Rietkuil rivers due to heavy rainfall and high runoff activities in their catchment areas.
The report said rivers in Windhoek were also in flood recently due to localised high intensity thunderstorms which caused damage to houses and road infrastructure.
It further said the water levels of eastern Cuvelai Iishanas started rising slowly since 6 January.
“Flow has been reported in some of the Cuvelai iishanas as a result of localised heavy rains in the Cuvelai-Etosha basin, but not because of the main Efundja coming from Angola.”
Flow into the Kunene, Okavango and Zambezi rivers continues with gradual rising.
The Zambezi River was on Wednesday measured at 1.28 metres, while the Okavango River was at 4.35 metres.
The flow of the Kunene River at Ruacana was 63 million cubic metres per second.
The hydrological services further said the lower Orange River’s flow is expected to rise because of additional releases from upstream dams in South Africa and additional flow from the Fish River as a result of rainfall development and dam releases from the Naute.
“Water users must be on alert for possible flooding and take the necessary precautionary measures.”