Small hydroelectric plants play an important role in devel-oping the socio-economy at a local level, but they are also a danger to residents.

The Ngoi San Hydro-electric plant in mountainous Lao Cai Province in north Viet Nam. Many new small hydro-power plants have been built recently. (Photo: VNS)

On Tuesday last week, a water pipe at the Dam Bol Hydroelectric Plant construction site in Lam Dong Province burst, killing two people and seriously injuring three others.

The subsequent flooding also washed away two houses.

On May 24 of this year, the An Khe Hydroelectric Plant in Gia Lai unexpectedly released a large volume of water that destroyed dozens of hectares of farmland and property.

In November last year, a canal in the Central Highland province of Dak Nong burst its banks, isolating more than 100 residents.

Associate Professor Bao Huy, a lecturer at the Tay Nguyen University, said local authorities regularly gave permission for the construction of hydroelectric plants, but did not stipulate river management regulations.

The Central Highlands has hundreds of small hydroelectric projects, but most investors struggle for capital and resort to using cheap, second-rate equipment.

Duong Chi Dung, head of the Environmental Safety Technology Division under the Dak Lak Department of Industry and Trade, said there were nine small hydroelectric plants in the province with a total capacity of 58MW, and all of them used equipment made in China.

“The equipment holds a latent risk because it is only made to last about 20-25 years, which is too short for a hydroelectric plant,” he said.

Investors needed about VND25 billion (US$1.2 million) to produce 1MW of electricity with Chinese equipment, whereas they needed VND55-70 billion ($2.7-3.5 million) if they used equipment made in Europe, said Dung.

Meanwhile, Dinh Van Tung, chief executive of the Bao Tan Electricity Company, the primary investor in the Dam Bol Hydroelectric Plant, said the Chinese made pipe that burst had been about 3.5km in length with a diameter of 1.6m.

The company had chosen that particular pipe because it was easy to install and neat, he added.

Construction work on hydroelectric plants has also encroached on Central Highland forests.

According to statistics from the provincial People’s Committee, Lam Dong had 70 small hydroelectric plants in 2004, and that number increased to 91 in 2008.

Deputy director of the province’s Department of Natural Resources and Environment, Luong Van Ngu said that to produce 1MW of electricity, 15ha of land was needed.

In Kon Tum Province, the provincial People’s Committee plans to complete 80 small hydroelectric plants by 2015, which means that a great amount of forests, lakes and streams will be affected.

General Secretary of the Viet Nam Association for Conservation of Nature and the Environment Pham Binh Quyen said that small hydroelectricity plants may not discharge waste like thermo-electric plants, but they did destroy natural resources and biological diversity.

“Dams have a serious effect on water supply further downstream. As reservoirs gradually fill, water is cut off and this can lead to drought, killing animals and forests, and endangering people. With the trees gone, there is nothing to soak up the water when it is eventually released, and this can lead to flooding,” he said.

Hoang Si Son, permanent deputy chairman of the Lam Dong People’s Committee, said the committee only issued permits for projects that did not affect the environment or encroach on forests or agricultural land.

“Before we issue a permit, we assess the investors’ financial and management capacity, and ask them to pledge to protect the environment,” he said.

Construction was also under the committee’s supervision, he said.

The accident at the Dam Bol Hydroelectricity Plant was due to a technical error. The committee had learnt from the experience and would strictly supervise future construction work, he added.

VietNamNet/Viet Nam News