Planned new dam at Vioolsdrift

[Andre]

I have put this under "Estuaries", in the Conservation section.

While at Amanzi camp this week, during my Orange River drift. I had an interesting conversation with the camp owner.
There is aplan to build a dam at Viools drift, with the main purpose to provide a more consistent flow of water through to the mouth at Oranjemund. at the moment, the mouth, and the Orange River estualy, is far to saline, which is killing the plant life, and threatening the bird population. The main school of thought, is to be able to have a consistent flow of 2 cumecs through the mouth, which can be dammed up and opened by bulldozers at any time, to control the salinity. It seems that they have finally acknowledged that the lower Oramge is a problem, and due to the artificial nature of the flows from Bloemhof and Vanderkloof, something needs to be done to preserve what is left of the natural environment at the mouth. Damming the river seems to be the only way to restore some form of consistency.
The dam is planned for 2018.
anyone know anything more?????

[core fly]

It could have an negative effect on the environmet too.
Look at the Gariep dam.I saw photos of the stretch from gariep to aliwal and you cant imagine what it looks like now.It used to be this beautiful rocky river up into lesotho and now that section is no more than a sand trap.
I recon the same could happen over decades and big floods to that section too,the big question is exactly where they intend building it and what type of "structure" will form the tail.If already deep sandy sections then no harm done I guess.

[Korrie]

The dams upstream of this "proposed dam" are the sand traps. if you look at the water flowing from Bloemhof and Van der Kloof, normally are quite clear. Down stream of these dams, there are very little rainfall, which will cause erosion. You will every now and again, have discoloured water, but nothing as the water that flows into the Gariep Dam. The placing of the Gariep dam is very bad, as you mentioned. it is positioned at a spot, where the Orange river goes from a fast flowing river, which can carry huge amounts of sediments, into a flat area, and it is dammed as well, so all the sediments can go to the bottom. This is one of the reasons why the Gariep dam, will not have its full "life expectancty" as it will be silted up.

[core fly]

A dam in that region might end up being a good thing,especially for us fly fishers.Could open a whole new world and awesome venue.Ja,it will never get like gariep i suppose,especially not in the time frame it took Gariep to silt up.
I was at tussen die riviere a while back and the photos from the time before gariep are uncomprehendible.Even the Caledon was magnificent.Now its a mud pit.Very sad.

[Korrie]

Some of the problems, like the "Caledon a mud pit" is from additional factors
a. over grazing in the catchment areas, which leads to higher erosion.
b. wrong planting methods, in the catchment areas.
c. global climatic change, which changes the rain patterns, and the plants.
d. higher incidence of veld fires, compared to 30 or 40 years ago.

[Andre]

Apparently its going to be a "bottom flow" Earth gravity dam..... something like the Stetynskloof on the Holsloot, and the Berg River dam. This allows the sediment to flow out.

The dams upstream of this "proposed dam" are the sand traps. if you look at the water flowing from Bloemhof and Van der Kloof, normally are quite clear. Down stream of these dams, there are very little rainfall, which will cause erosion. You will every now and again, have discoloured water, but nothing as the water that flows into the Gariep Dam. The placing of the Gariep dam is very bad, as you mentioned. it is positioned at a spot, where the Orange river goes from a fast flowing river, which can carry huge amounts of sediments, into a flat area, and it is dammed as well, so all the sediments can go to the bottom. This is one of the reasons why the Gariep dam, will not have its full "life expectancty" as it will be silted up.