Hold the Hydro-Powered Wagon!

At the Hydropower Africa Conference in Johannesburg earlier this week it was highlighted that hydropower could save Africa $2-billion a year in terms of electricity generation and regional power trade. While capital cost and infrastructure propose a current obstacle to developing hydropower, departmental governments attending the conference sat up and noticed.

Nelisiwe Magubane, director-general of South Africa's Department of Energy, said that the hydropower potential in Africa could not be underestimated at this critical time in the continent's development. Meanwhile WWF has

So it seems that in a time when our fellow Africans are rushing forward in hydropower, South Africa is still dealing with last year's issues. Should we just rush forward as well? When thinking about the environment, using rushing water to power a city does in theory sound much better than using coal. There is no smoke, no soot or radioactive waste. In fact a lot of people place hydropower  into the same safe, green category as wind power and solar power. But as with each of these, there are biodiversity and environmental impacts.

The worst version, from a biodiversity perspective, is the hydroelectric dams. These massive, concrete creation drown enormous amounts of land behind them, but do create the most amount of electricity. There are smaller versions of the hydroelectric dams, which cause less environment disruption, but also create less electricity.

The first obvious disruption is the impact behind the dam. Other than filling up previous ecosystems with water and drowning the valley, there are the aquatic ecosystems to take into account, both upstream and downstream. Downstream there will be erosion issues, water temperature changes and oxygen levels to take into consideration due to the water passing through the dam's turbines.

Then there is the valley that has just been drowned. Depending on the development of the dam, the ecosystem could be a wetland or even a forest. Either way that ecosystem was holding a lot of carbon, which will be released during the flooding and afterwards when the plants and trees start to decompose. This doesn't only release emissions from a global perspective, but alters the water chemically. Plus you add the concrete to build the dams and transportation to get the materials to the site and the negative effects start really adding up.

It's not only the position of the dam that needs to be taken into consideration, but also were the water ends up. Wetlands and river mouths will be influenced by the dam. Of course you could argue the negative environmental impacts of coal-fuelled power plants, which are more obviously visible than a pretty waterfall. The full impacts of hydropower have still yet to be researched. While the concept is supported by organisations such as WWF, in their statements they always bring up the fact that serious considerations need to be taken into account and proper research has to be done before even the first wheelbarrow of cement is shipped out.

Locations are vitally important and in a country were water is already scarce, it is even more so. The second thing to take into account is the biodiversity, not only on the land, but in the freshwater. Already over 20% of freshwater fish species have gone extinct globally. In South Africa, almost 50% of freshwater ecosystems are critically threatened.

South Africa doesn't have the best track record of looking before walking. But hopefully we would have learnt from our neighbours in Zambia, who after building dams in the 1970s, completely disrupted and reduced water in the area and changed the timing of the flooding in the Kafue Flats upstream. The negative effects not only included in water resource availability and impacts on wildlife and fish, but also reduced potential for tourism.

At this moment in time, hydropower in South Africa is still majority only a theory. Although according to the White Paper in Renewable Energy, South Africa areas in the Eastern Cape and KwaZulu-Natal provinces show a lot of potential for the development of small hydropower plants. Currently the white paper, published in 2003, has the following target for 2013:

"10 000 GWh (0.8 Mtoe) renewable energy contribution to final energy consumption by 2013, to be produced mainly from biomass, wind, solar and small-scale hydro. The renewable energy is to be utilised for power generation and non-electric technologies such as solar water heating and bio-fuels. This is approximately 4% (1667 MW) of the estimated electricity demand (41539 MW) by 2013."

Irrespective of the size of installation, any hydropower development will require authorisation in terms of the National Water Act (DWAF, 2003).

Article Source: http://www.articlesbase.com/environment-articles/hold-the-hydro-powered-wagon-3301163.html

Celeste works for South African Biodiversity Media. To find more articles, news and information about biodiversity and environmental issues in South African, go to www.southafricanbiodiversity.co.za

Other Resources for this article:
WWF
Renewable Energy White Paper South Africa