R/€ = 15.09Change: 0.16
R/$ = 13.42Change: 0.13
Au 1145.84 $/ozChange: -0.61
Pt 945.50 $/ozChange: 11.00
Note: Search is limited to the most recent 250 articles. Set date range to access earlier articles.
Where? With... When?

And must exclude these words...
Close Main Search
Close Main Login
My Profile News Alerts Newsletters Logout Close Main Profile
Agriculture   Automotive   Chemicals   Competition Policy   Construction   Defence   Economy   Electricity   Energy   Environment   ICT   Metals   Mining   Science and Technology   Services   Trade   Transport & Logistics   Water  
What's On Press Office Tenders Suppliers Directory Research Jobs Announcements Letters About Us
RSS Feed
Article   Comments   Other News   Research   Magazine  
Oct 12, 2012

Proposed Zambezi hydropower dams pose some risks, expert warns

Construction|Africa|Flow|Hydropower|Projects|Resources|Safety|SECURITY|System|Water|Africa|Energy|Flow|Power Generation|Power-generation|Services|Batoka Gorge|Zambezi|Zambezi River|Power|Richard Beilfuss|Rudo Sanyanga
Construction|Africa|Flow|Hydropower|Projects|Resources|Safety|SECURITY|System|Water|Africa|Energy|Flow|Power Generation|Power-generation|Services||Power|
© Reuse this

Existing and proposed hydropower dams are not properly evaluated for the risks of natural hydrological variability, which is extremely high in the Zambezi river, not to mention the risks posed by climate change, says US State of Wisconsin Department of Safety and Professional Services hydrologist Dr Richard Beilfuss.

“The result could be that uneconomic dams underperform in the face of more extreme drought and more dangerous dams that have not been designed to handle increasingly damaging floods,” he notes.

Overall, Africa’s fourth-largest river will experience worse droughts and more extreme floods. Dams currently being proposed and built will be negatively affected, yet energy planning in the basin does not include the necessary steps to address these significant hydrological uncertainties, he warns.

The basin exhibits the worst potential effects of climate change among 11 major sub-Saharan African river basins. It will also experience the most substantial reduction in rainfall and runoff, according to the International Panel on Climate Change. Multiple studies estimate that rainfall across the basin will decrease by 10% to 15%.

“The basin is likely to experience significant warming and higher evaporation rates in the next century. Because large reservoirs evaporate more water than natural rivers, big dams could worsen local water deficits, resulting in less water for hydropower. Currently, more than 11% of the Zambezi’s mean annual flow is lost to evapora- tion from large hydropower dam reservoirs, which increases the risk of shortfalls in power generation and significantly impacts on downstream ecosystem functions,” he explains.

The designs for two of the larger dam projects proposed for the Zambezi, the Batoka Gorge and Mphanda Nkuwa dams, are based on historical hydrological records and have not been evalu- ated for the risks associated with reduced mean annual flows and more extreme flood and drought cycles. Under future climate scenarios, these hydropower stations, which are based on records of flows, are unlikely to deliver the expected services, says Beilfuss.

The occurrence of more frequent extreme floods threatens the stability and safe operation of large dams. Extreme flooding events, a natural feature of the Zambezi river system, have become more costly downstream since the construction of large dams. If dams are ‘underdesigned’ for larger floods, the result could be serious safety risks to millions of people living in the basin.

The Zambezi river is already highly modified by large hydropower dams, which have profoundly altered the hydrological conditions that are most important for downstream livelihoods and the preservation of biodiversity. The ecological goods and services provided by the river, which are key to enabling societies to adapt to climate change, are under grave threat.

Large-dam hydropower poses economic and adaptation risks. Africa has been referred to as the continent most at risk of being nega- tively affected by climate change. Successful adaptation will require new ways of thinking about water resources. We need to act now to protect our rivers as sources of livelihoods and food security,” says International Rivers Africa programme director Rudo Sanyanga.

“The region’s energy planners and governments must acknowledge these hydrological risks and take steps to improve planning and manage- ment of large dams in the basin. Existing and future dams should, at least, undergo a thorough analysis of climate risks,” notes Beilfuss.

Edited by: Martin Zhuwakinyu
Creamer Media Senior Deputy Editor
© Reuse this Comment Guidelines (150 word limit)
Other Environment News
The City of Cape Town has successfully reapplied for an environmental-impact assessment (EIA) for its routine stormwater management activities following changes in national legislation; however, this time, the city gained citywide authorisation. The City of Cape Town...
The much anticipated traffic restrictions into Sandton, Johannesburg, began Monday as the EcoMobility World Festival took off. Organisers said the festival aims to demonstrate the possibilities and benefits of urban mobility without dependency on private cars in a city.
Energy analyst and EE Publishers MD Chris Yelland warned recently against excessive optimism regarding timescales for the proposed construction of new nuclear power plants (NPPs) in South Africa. He was speaking at a Nuclear Roundtable in Johannesburg. “I think we...
Latest News
Updated 2 hours 16 minutes ago World-renowned fuel cell scientist Dr Sharon Blair would like to see South Africa supply 25% of the global demand for fuel cells by 2020, stating that the country has a tremendous opportunity to develop the industry and capture a share of the growing sector. However,...
Updated 2 hours 39 minutes ago Public Enterprises Minister Lynne Brown should table an uncensored contract agreement between Eskom and one of its coal suppliers owned by the Gupta family, the Democratic Alliance (DA) urged on Wednesday. The Sunday Times reported on September 13 that Gupta-owned...
Updated 2 hours 55 minutes ago Cosatu's provincial general secretary, Tony Ehrenreich, had strong words for government and higher income groups as union members marched to Parliament on Wednesday. “We want them to tax the people who live in Clifton and Sea Point,” he demanded, saying workers...
Recent Research Reports
Liquid Fuels 2015: A review of South Africa's liquid fuels sector (PDF Report)
Creamer Media’s Liquid Fuels 2015 Report examines these issues in the context of South Africa’s business environment; oil and gas exploration; fuel pricing; the development of the country’s biofuels industry; the logistics of transporting liquid fuels; and...
Road and Rail 2015: A review of South Africa's road and rail sectors (PDF Report)
Creamer Media’s Road and Rail 2015 report examines South Africa’s road and rail transport system, with particular focus on the size and state of the country’s road and rail infrastructure and network, the funding and maintenance of these respective networks, and...
Defence 2015: A review of South Africa's defence sector (PDF Report)
Creamer Media’s Coal 2015 report examines South Africa’s coal industry with regards to the business environment, the key participants in the sector, local demand, export sales and coal logistics, projects being undertaken by the large and smaller participants in the...
Real Economy Year Book 2015 (PDF Report)
There are very few beacons of hope on South Africa’s economic horizon. Economic growth is weak, unemployment is rising, electricity supply is insufficient to meet demand and/or spur growth, with poor prospects for many of the commodities mined and exported. However,...
Real Economy Insight: Automotive 2015 (PDF Report)
Creamer Media’s Real Economy Year Book comprises separate reports under the banner Real Economy Insight and investigates key developments in the automotive, construction, electricity, road and rail, steel, water, gold, iron-ore and platinum sectors.
Real Economy Insight: Water 2015 (PDF Report)
Creamer Media’s Real Economy Year Book has been divided into individual reports under the banner Real Economy Insight and investigates key developments in the automotive, construction, electricity, road and rail, steel, water, coal, gold, iron-ore and platinum sectors.
This Week's Magazine
Sphere Holdings CEO Itumeleng Kgaboesele
Black-owned investment holding company Sphere Holdings plans to raise a further R1-billion in the coming months in support of its strategy to become a leading black industrial enterprise, which could ultimately seek a listing on the JSE.
Energy analyst and EE Publishers MD Chris Yelland warned recently against excessive optimism regarding timescales for the proposed construction of new nuclear power plants (NPPs) in South Africa. He was speaking at a Nuclear Roundtable in Johannesburg. “I think we...
Malawi’s Lilongwe Water Board (LWB) is inviting eligible bidders to prequalify for the board’s efficiency improvement works, which will be implemented as part of the E24-million Lilongwe Water Resources Efficiency Programme.   LWB CEO Alfonso Chikuni explains that...
CROATIA, AN EU MEMBER BUT NOT A TDCA MEMBER On July 1, 2013, Croatia officially became the twenty-eighth member of the European Union (EU). Despite Croatia’s accession into the EU, it is yet to become party to the Trade, Development and Cooperation Agreement (TDCA)...
The Council for Scientific and Industrial Research (CSIR) has announced that its new Inundu airborne electronics testing, evaluation and training pod had made its first test flight on September 10. The successful flight was undertaken from Lanseria International...
Alert Close
Embed Code Close
Research Reports Close
Research Reports are a product of the
Research Channel Africa. Reports can be bought individually or you can gain full access to all reports as part of a Research Channel Africa subscription.
Find Out More Buy Report
Engineering News
Completely Re-Engineered
Experience it now. Click here
*website to launch in a few weeks
Subscribe Now for $96 Close
Subscribe Now for $96