amid heated public debate about the impact of small hydropower plant construction on flooding and landslides.

Rao Trang 4 Hydropower plan in the central province of Thua Thien-Hue. VNA/VNS Photo

He added that issues relating to forest and land in all power projects were examined carefully before the projects were included in national electricity development planning.

Before 2016, to generate a single MW, about 4-5ha of land was required but from 2016, no hydropower plant project was developed on natural forest land, he said.

In projects developed on plantation forest, on average 2ha was needed for every MW.

“Thanks to the Government’s policies and directions, investors and local governments are better aware of forest land use and thus, minimise the use of forest land in their projects,” the minister said.

Since 2017, all power projects with a capacity of less than 3 MW have not been eligible to be in national planning. Responding to discussions on the impact of small hydropower plants on landslides and floods, Anh said landslides also happened at places other than hydropower plants’ locations.

“The operation of reservoirs and hydropower plants in localities were okay during the past time. For example, Đắk Mi 4 Plant did a good job in regulating floodwater and helping reduce flood levels a few days ago,” he said. 

Experts' views

Small hydropower plants could help deal with small floods but are little help amid massive floods like those that have occurred in recent weeks in central Vietnam, experts have said.

Links between small hydropower plants and floods were discussed at a talk organised by Vietnam Digital Communications last week.

At the talk, Dr Vu Thanh Ca, a lecturer of Hanoi University of Natural Resources and Environment said that there is no scientific basis to say hydroelectricity increases floods.

Many people believe hydroelectricity left negative impacts on the environment, ecosystem and increased erosion by blocking the flow of mud/sand and posed a huge risk of flash flooding if the dam fails, he said.

“However, if there were no hydroelectric dams, floods would still happen, or be even higher. In many cases, without a hydropower reservoir, floods would be much higher,” he said.

In Vietnam, reservoirs at hydropower plans were operated under regulations including those related to water storage and water discharge.

“Reservoirs can store water better than the forest,” he said, adding that forests could hold a maximum 0.2m height of water while reservoirs could hold 4m.

“Water is an asset, hydropower managers do not want to discharge water," he said.

“Furthermore, small hydroelectric plants do not have a flood regulation function, so they discharge as much as the volume of water running into the reservoir. There is absolutely no reason for extra discharge,” he added.

In any case, the amount of discharged water is always less than or equal to the amount of inflow water, so hydroelectricity does not create more floods.

In the central region, small hydropower plans helped ensure energy security when wind power and solar power failed to meet demand, he said.

However, Ca also noted that in some cases, the construction of the hydropower plant was taken advantage of for deforestation or illegal construction of roads or factories. 

Nguyen Tai Son, a senior consultant in hydropower plant projects, said small hydropower plants usually had small reservoirs or no reservoirs, so they were not designed to regulate flooding.

Only major hydropower dams with huge reservoirs could store a significant amount of floodwater, thus effectively reducing and preventing floods. The dam at Hoa Binh Hydropower plan in the north is an example as since the dam was built, people living along the Hong (Red) River no longer suffered major floods.

Meanwhile, small hydropower plants in the central province in some cases helped reduce floods as they stored a volume of floodwater and discharged floodwater at lower speeds, he said.

Son said that in hydropower projects, the reservoir was an important item that affected the environment and the safety of hydropower projects, so the reservoir construction must be considered carefully before an investment licence was granted.

Ca said when it came to hydropower, project assessment and approval must be done as seriously as possible, particularly environmental impacts assessment and plans to mitigate the impacts of reservoir/dam construction on the environment.

He said bottom outlets should be included in the dam construction project to release mud/sand to lower areas as it was also a kind of resource.

“Water discharging schemes must be developed, approved and implemented to minimise the risk of floods and impacts on the ecosystem,” he said.  

Do Duc Quan, Vice Director-General of the Electricity and Renewable Energy Authority under the Ministry of Industry and Trade, said that since 2016, the ministry had not approved any hydropower project on natural forest land.

The ministry and localities were reviewing hydropower development planning in which hundreds of hydropower projects would be removed from planning as they occupied a lot of land or possibly left negative impacts on the environment, he said.

There are more than 800 hydropower plans of all kinds across Vietnam including about 600 in operation, he said, adding that once developed, they had to satisfy requirements in laws such as the Law on Construction or Law on Electricity. 

Answering the local press on the sidelines of the National Assembly session late last month, Minister of Natural Resources and the Environment Tran Hong Ha said the principle of his ministry is "not to develop small-scale hydropower at any cost".

“There are always two sides of a coin. The environment ministry doesn’t encourage the development of small-scale hydropower at any costs,” he said. 

“Ministries and agencies have proposed cutting more than 400 small hydropower reservoirs. In the future, we will be very cautious when building small hydropower plants,” he said. VNS

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