6K – Eutrophication – Hartebeespoort Dam

Supporting article K:  “Water, water everywhere, and not a drop to drink.” Poet: Sameul Taylor Coleridge. An article on the state of the once beautiful Hartebeespoort Dam.

http://www.news24.com/SouthAfrica/News/Dams-water-undrinkable-20070320

Dam’s water ‘undrinkable’
2007-03-20 14:19

Johannesburg – The poet Samuel Taylor Coleridge did not have North West province’s Hartbeespoort dam in mind when he wrote the words, “Water, water everywhere, nor any drop to drink”, but they are a fitting description of its contents.

The water in the dam is so polluted the region’s bulk water supplier, Rand Water, is building a 50km-long pipeline from Brakfontein to Hartbeespoort to ensure residents in the area have a supply of clean drinking water.
The pipeline, one of Rand Water’s current infrastructure projects, is being built at a cost of R310m.
Briefing Parliament’s water affairs portfolio committee on Tuesday, Rand Water chief executive Themba Nkabinde admitted the project might sound a little crazy.

“We have the Brakfontein-Hartbeespoort pipeline to supply water to the areas around the Hartbeespoort dam, which might sound a bit crazy because they have water at the dam, but we are supplying water from our current network.
“Unfortunately the Hartbeespoort dam doesn’t have water that can be purified at reasonable cost to potable standards, so we have to supply from the rest of our network,” he told MPs.

The Hartbeespoort Dam, which has a surface area of about 20 square kilometres, is often cited in water management literature as one of the world’s most severe examples of water “eutrophication”.
Eutrophication is what gives the water in the dam its distinctive green colour. It is caused by high levels of phosphates and nitrates washing into the dam from surrounding agricultural lands and upstream sewage treatment works in Gauteng.

The high pollution content promotes the growth of algae, which grow rapidly and deplete the oxygen content of the water.
– SAPA