Find the cause of the landslide at the Rao Trang 3 hydroelectric power station?

At the seminar on “Small Hydropower and the Flood Problem”, held in Hanoi this morning (October 30), Associate Professor Dr. Vu Thanh Ca, Faculty of Environment, Resource University Natural and Environment According to the report, the landslide at the Rao Trang 3 hydroelectric power station (Phong Dien district, Thua Thien Hue province) recently may be partly due to the activities of clearing mountains to level the ground for houses .

In his speech, Mr. Ca gave an analysis of the impacts of hydroelectricity on the environment, in particular: Hydroelectric reservoirs will flood a considerable area of ​​important forests and wetlands. The discharge of water to another basin could cause drought in the riparian areas downstream of the dam.

Also, not discharging enough water (in other words, not guaranteeing environmental flow) will degrade downstream river habitats.

“In particular, hydroelectricity will deposit a large amount of sand on the lake bed, gradually reducing the capacity of the reservoir and causing erosion downstream of the dam, as well as related coastal areas,” Ca said.

Furthermore, hydroelectric power also prevents the migration of many species of shrimp and fish, especially many valuable species of fish. Therefore, it can represent a great risk to aquatic resources.

Mr. Ca takes a closer look at the environmental impact of hydroelectric reservoirs: hydroelectric propellers also sweep away and kill many fish and shrimp; Stagnant water in the lake also changes the hydraulic system of the river and causes eutrophication if the supply of nutrients is large.

In addition, the construction of lakes and hydroelectric dams also lost some forest; Flooding of the lake bed can also cause geological instability, leading to landslides as in the example of the Rao Trang 3 hydroelectric power station mentioned above.

In the view of Mr. Vu Thanh Ca, the forest area destroyed for the operation of the hydroelectric power station is much smaller than that of the forest destroyed on the lake bed.

“There is deforestation to make hydroelectric dams, but it is a problem for the rangers, not the problem of hydroelectricity,” said Mr. Ca.

Regarding solutions to overcome the above limitations, Mr. Ca said that when building hydroelectric plants, care must be taken when designing and building; must prepare, evaluate and seriously approve an environmental impact assessment report with a plan to minimize the environmental impact of hydroelectric lakes and dams to ensure that all environmental impacts are considered and mitigated. that hydroelectricity brings.

“Hydroelectric dams must design and build ‘fish ladders’, which are steps where water continually flows from the top of the dam to the base of the dam to ensure that fish can migrate upstream and over the dam,” Ca said.

According to Mr. Ca, hydroelectric dams must also be properly planned to avoid flooding in flooded areas of environmental and ecological importance; Careful investigation and resettlement of people is required in areas at risk of landslides and floods.

In addition to the harmful effects of hydroelectric reservoirs, according to Mr. Ca, in the world, hydroelectricity is considered a form of clean, renewable energy, it does not produce toxic waste, …

Is the Ministry of Industry and Commerce aware of the Rao Trang 3 environmental impact assessment report?

Before the question of, is the Ministry of Industry and Commerce aware of the environmental impact assessment (EIA) report of the Rao Trang 3 hydroelectric project and the warnings that this area is at risk of landslide? Mr. Do Duc Quan – Deputy Director of the Department of Electricity and Renewable Energy (Ministry of Industry and Commerce) said: Information about the recent accident, the main works, dams, factories of Rao Trang 3 are “no What’s the problem” .

“No, he slipped on the side of National Highway 71 and on the slope and about 500 meters from the site of the Rao Trang 3 hydroelectric power station dam. The EIA is the responsibility of the Ministry of Natural Resources and Environment, we have can participate from a technical perspective of the work. When the Natural Resources and Environment side requires the work to be done, we will ask the investor to do it, while in professional environmental issues, The Thai … belongs to the environment side. ” Quan said.

With regard to landslides, Quan said, this Ministry is only responsible for the main construction, how to ensure that the dam is safe, the spillway is capable of unloading when there is flooding, and can be regulated.

Also related to the Rao Trang 3 hydroelectric project, this project was initially 11MW in size and had to convert more than 12ha of forest land. But then this project increased to 13MW and converted more than 40ha of forest land. If the calculation of the specialized agency of the Ministry of Industry and Commerce is 1.09ha / 1MW, the Rao Trang 3 hydroelectric project is exceeding this rate.

Mr. Quan explained: “In the beginning, the Rao Trang 3 hydroelectric power station had a total area of ​​more than 60,000 ha, then it was reduced to more than 40,000ha, including all kinds of land, including 12ha of forest. -13MW is a technical problem, maybe up to 18MW, but because of the economic problem they don’t. I think it’s normal, “said Mr. Quan.

Quan added that hydroelectric projects that have a great impact on environmental issues, safety issues in downstream areas … most of them have been reviewed and eliminated from the planning according to the content required by the country. Develop hydroelectricity in a sustainable way, without generating negative impacts on the environment and social, to ensure the efficiency of the investment.

On the issue of monitoring the implementation of the EIA for small and medium hydroelectric projects, because generally “a good preliminary verification, but not a good later verification”. Furthermore, although the law requires hydroelectric projects to ensure a “minimum flow” during the dry season, the inspection practice still violates a lot, especially for small and medium-sized hydroelectric plants.

Responding to the above content, Mr. Quan said that the decision level on investment policy for small hydroelectric projects is the Popular Committee of the province or city. The supervisor during the implementation of these projects can be the Department of Industry and Commerce, but some provinces can also assign it to the Department of Agriculture and Rural Development for a better experience in irrigation and dams.

Nguyen duong