SA dams: a rapidly worsening water crisis

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 27 June 2010

By Bill Harding, a limnologist (aquatic sciences), who has been involved with issues to do with SA dams since the ’70s

South Africans will be aware that our country is not blessed with abundant rainfall, with an average of only 450mm a year, compared with the global average of 860mm a year.

Without substantial supplies of underground water, we rely heavily on water that is stored in dams. Our reliance on stored water is rendered critical by population growth and industrial expansion. Water resources per capita of population are dwindling.

Brandvlei Dam. Pressure on many dams is increasing, with a considerable portion of their inflows made up of wastewater effluents and urban runoff.

At the same time, pressure on many dams is increasing, with a considerable portion of their inflows made up of waste-water effluents and urban runoff.

The Department of Water Affairs and Environment manages 574 dams, of which 320 are major dams, each holding more than a million cubic metres of water. From this storage, irrigation uses 62%; urban and domestic use equals 27%; and mining, industry and power generation absorb 8%. Commercial forestry utilises 3%.

Evidence suggests that the quality of about 35% of the storable volume is already severely impaired – and nearly all of this in the economic heartland of Gauteng. Water quality is in fact poorest in the areas with lowest runoff and highest contribution to GDP.

Insidious and sinister changes are appearing in some dams, completely unnoticed by routine monitoring programmes. From this it may be reasonably assumed that SA would possess a national programme for reservoir management.

In recent months there have been many reports referring to a water crisis, mentioning the extreme levels of pollution in most Gauteng dams.

It will come as a shock to learn that SA has no such programme. None of our academic institutions teaches limnology (aquatic sciences) as a career subject, and the Department of Water Affairs, custodian of our water resources, has no directorate of reservoir management that co-ordinates appropriate management of our dams.

Curiously, the National Aquatic Ecosystem Health Monitoring Programme does not mention the word “dams”. So what is the condition of South African aquatic sciences?

“South African limnology is in disarray. It is poorly funded, failing to address certain important environmental problems, lacks a cohesive sense of direction and its potential contributions to effective water-resource management are grossly underrated.”

This statement is, in several ways, almost as true now as it was back in 1989 when it was made by one of the world’s most eminent limnologists, the late Dr Bill Williams.

Williams’s report was commissioned by the then Foundation for Research and Development, a unit that existed within the Council for Scientific and Industrial Research. It was compiled at the time the foundation was terminating its inland-waters ecosystem research programme, which encompassed a number of projects spanning all aspects of aquatic sciences.

The Williams report was kept secret by its initiators. The foundation considered that “it would be counterproductive to enter into open debate on the issues raised by the evaluation”, yet noted that “the future of limnology activity (is) of concern”.

As with other administrative crises, there is no time available for finger-pointing. The problems must be assessed, sleeves rolled up and the issues practically and pragmatically addressed. The logical question is, “what is the status of South African aquatic sciences now”?

South African limnology post-1989 has suffered a massive decline – especially with respect to lake (dams) science and management. This was in part underpinned by inaction on the part of the Department of Water Affairs.

The emergence of the Williams report, however, suggests that, in the absence of guidance from the scientific community, the department could reasonably assume that there was no cause for concern.

The years following 1990 saw increased direction of funding into river biology and ecology – almost to the exclusion of anything else in aquatic science. Oddly, despite the punctuation of most South African rivers by dams, there have been no calls from the river ecologist fraternity for the authorities to hasten attention thereto.

A wealth of limnological information has been generated by local authorities and water supply agencies. The bulk of this work was born of a self-preservation need to, in the absence of nationally funded support, understand and manage the nature of the water resources being treated and supplied to consumers.

Regrettably, most of this developed knowledge base remains inaccessible. South African limnologists are few and far between, effectively working in silos. Competition for funding is fierce, resulting in a reluctance to collaborate.

There is little to be gained from picking apart why the Williams report was kept secret. It was a far-sighted, unemotional and accurate analysis of limnology in South Africa. Had it been brought into the open at the time, it would have served as the road map to guide limnology into the new South Africa.

We should perhaps draw solace from the notion that it is never too late to learn. Equally so, with scarce water resources, sooner is better than later.

In the absence of a well-funded and cohesive strategic plan for South African limnology, the country will remain ill-equipped to manage its impounded water supplies.

The rapidly worsening condition of South Africa’s dams will soon catapult the problems they pose to the fore. More than ever before there is a need for fully integrated (rivers, wetlands, dams) assessment and management.

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