Von Bach Dam Sluices Opened For The 5th Time In 50 Years

5 Mar 2020

Dirk Heinrich 

For only the fifth time ever, the sluices of the Von Bach Dam near Okahandja had been opened at 21.00 hours on Sunday 1st March 2020 to release water after the water level reach the 100 percent full capacity mark. The gates were closed at 05.00 hours Monday morning after the level was back at 99%. 

The Von Bach Dam was finished in 1970 and four years later in 1974 the sluices were opened for the first time to release water downstream. It took 32 years before the sluices were opened for the second time in 2006. Three years later in 2009 NamWater opened the sluices for the third time ever. In 2011 the two sluices of the Von Bach Dam were opened for the fourth time and water rushed down the Swakop River into the Swakoppoort dam. If both sluices are opened 12 meters, which is the maximum, 2000 cubic meters of water are released per second. This has never been done though. When one sluice is opened half a meter (0.50 m) 62 m³/sec are released. 

Although the three dams supplying water to Windhoek have received magnificent inflow, citizens should still save water and not waste the precious commodity. Since July last year (2019) Windhoeker´s hardly managed to save the prescribed 15% of their normal amount which did show that people did not care and could have been in a disaster situation now. 

Not that lucky are the people in the south were the largest dam belonging to NamWater, the Hardap dam has only risen to 28,7 % after being down to just over 5%. Water supply to the irrigation scheme downriver had come to a standstill end of January and cannot be resumed yet because the canal is damaged close to the dam. 

The dams storing water for the east of the country (Gobabis) still need a lot of inflow since their total is only 21 %. Eventually some water has reached the Omdel dam which has been dry most of the time since it was built and the Bondels dam near Karasburg is more than 100% full.

NamWater announced that all the dams in the country were filled with 47,6 % of their full capacity on Monday 2nd March 2020. This means there are 331,617 million cubic meters of water in all NamWater dams. Last year at the same time there was 33,6% and 234,071 million / m³ country wide available. If all 17 dams in the country are full, they store 695,984 million/m³. Once the newly build Neckartal dam is full it can nearly store three times the amount of the Hardap dam and more than the total of all NamWater dams in the country namely 880,000 Mm³. At the moment the dam does not belong to NamWater and is therefore not listed on the dam bulletin. 

On Monday this week (2nd March 2020) NamWater announced the following percentage for the different dams and in brackets the percentage last year at the same time: 

 

Swakoppoort dam69,1% (18,3%) 

Von Bach dam99,4% (47,3%) 

Omatako dam52,2% (0,6%) 

SUBTOTAL CENTRAL73,7% (22,2%) 

 

Friedenau dam44,5%(29,5%) 

Goreangab dam101,5%(100,2%) 

SUBTOTAL WINDHOEK64,5%(54,2%) 

 

Otjivero dam16,9% (4,1%) 

Otjivero silt dam21,6% (0,0%) 

Tilda-Viljoen dam32,7% (4,3%) 

Daan-Viljoen dam69,1% (4,2%) 

SUBTOTAL GOBABIS21,0% (2,5%) 

 

Hardap dam28,7% (28,1%) 

Naute dam87,1% (99,9%) 

Oanob dam90,5% (53,9%) 

Dreihuk dam15,4% (1,1%) 

Bondels dam102,8% (0,0%) 

SUBTOTAL SOUTH44,8% (43,1%)

 

Olushandja dam28,5% (20,2%) 

Omaruru Delta dam3,7% (0,0%) 

Omatjenne dam11,9% (0,0%)

Our photographs show the irrigation canal between Hardap dam and Mariental which is empty since end of January when water supply to the irrigation scheme was stopped for the first time in history. Since then the Hardap dam has received inflow and stands at 28,7 %, but the canal has been damaged and needs repair work before any water can be let into the canal again. The photos taken on the 28th February show how empty the Hardap dam still is, just 0,6 % more than last year at the same time. 

The second set of photos show people in a green landscape with yellow flowers waiting at Von Bach dam for the sluices to be opened on Saturday 29th February 2020. This only happened on Sunday night when the dam was 1005 full. In the pictures the manager hydrology of NamWater André Mostert can be seen standing on the dam wall above the two sluices. The debris floating on the water along the dam wall can be clearly seen. Between the natural plant matter hundreds of plastic bottles and a huge float can be recognized which belongs to nobody but could be chocked in one of the sluices.