31 Oct 20 Vietnamnet Source Natural disasters and floods have devastated central Vietnam at a record level. So far, 130 people have been reported dead, and 18 others are missing.

Record floods and rain

According to a report from the Steering Committee for Natural Disaster Prevention and Search and Rescue of Thua Thien - Hue Province: "From October 6 to October 13, Thua Thien – Hue province suffered heavy rains, covering a large area, with rainfall from 1,500 - 2,000mm, and up to 2,869mm in Bach Ma and 2,208 mm in A Luoi. The water level on Bo River peaked at +5.24m at Phu Oc station, exceeding the historic flood peak in 1999 by 0.06m. On the Huong River, the water level was +4.17m at Kim Long station, above the alarm 3 of 0.67m, causing severe floods."

The rain that lasted from October 6 to 13 had a total heavy rainfall equivalent to the 1999 flood, which caused grief for many, leading to hundreds of people either dead or missing.

Do hydropower projects stimulate flooding?

Phan Thanh Hung, Head of the Steering Committee for Disaster Prevention, Search and Rescue of Thua Thien - Hue Province, said that, with such high rainfall, the total amount of water flowing to reservoirs in the Huong river basin has been about 3.7 billion m3, of which about 1 billion m3 has been retained in reservoirs. The remaining amount of water flowing downstream was about 2.7 billion m3, combined with the rainfall in the delta of about 1.4 billion m3, so the delta has a total water volume of about 4.1 billion m3.

According to calculations by relevant agencies, with the storage capacity of hydropower and irrigation reservoirs in the province, the level of flooding on the Huong River fell by more than 1m and about 0.5m for the Bo River.

From this data, Mr. Hung said that without large hydropower and irrigation reservoirs to accumulate water, the consequences would have been unpredictable.

Concern about hydroelectricity

Hydroelectric insecurities have existed for a long time, and are controversial. When the National Assembly discussed the plan to build Son La hydropower plant in December 2002, Deputy Chairman of the National Assembly's National Defense and Security Committee Nguyen Van Kha raised a shocking question: "If the Son La dam breaks, a 4-ton tank in Son Tay will be blown away like a yellow leaf. After 30 minutes, the whole Northern Delta will sink by 4-60m deep and 15 million people will die."

That warning caused controversy for many years thereafter.

Recently, in an interview with VietNamNet, former Energy Minister Thai Phung Ne said: "That is such nonsense." He explained that all large and small hydroelectric dams must be designed according to very strict standards and regulations of the State.

Every year, before the flood season, hydropower projects such as Hoa Binh, Son La, and Lai Chau must check the opening/closing equipment one by one. All information obtained must be immediately presented to the State Scientific Council for dam safety.

Each year the Council meets and re-examines all of those hydroelectric plants, based on data observed over a year. The dams have sufficient monitoring equipment, using modern technology. Data will be transferred immediately through the electronic system to the control room.

All stages related to the construction and operation of these hydropower plants are evaluated and approved under strict procedures and standards to prevent disasters.

Decentralization

In Thua Thien - Hue province, Rao Trang 3, where the current incident occurred that killed 18 workers, is a hydroelectric plant with an investment of VND290 billion, built on the Rao Trang River, a branch of Bo River, in Phong Xuan commune, Phong Dien district.

Rao Trang 3 is just one of dozens of small hydropower projects in this province. Thua Thien - Hue has 21 hydropower projects of various scale, with a total capacity of 450MW, including five major projects: A Luoi, Huong Dien, Binh Dien, A Lin 1 and Ta Trach with total capacity of 360MW.

This number of hydropower projects exceeds the province's plan in 2008, which set a target of building only 11 hydropower plants, with a total capacity of about 105.8MW.

Long ago, the Water Resources Management Department of the Ministry of Natural Resources and Environment issued a warning: Hydropower projects that have been under construction in Thua Thien-Hue are mostly large dams with reservoirs with a capacity of dozens to hundreds of millions of cubic meters of water. When dams are built, they often flood a large area of land in the lake bed area, and in the process of operation, they also affect resources and environment in the river basin.

Cautious attitude
From a state management perspective, the Ministry of Industry and Trade is also very cautious with hydropower construction. In 2017, the Ministry issued a warning that some provinces regularly requested the Ministry to update the hydropower development planning based on proposals of businesses that did not have an overall approach and comprehensive research on the exploitation of hydropower potential, and which were not really consistent with electricity planning of local governments and did not ensure socio-economic development and environmental protection.

In 2017, the Ministry also issued a directive, which said that the agency did not consider or do research to add hydropower projects with a capacity of 3.0 MW or less to the national hydropower development plan. In fact, since then, the ministry has not added any hydropower projects that occupy natural forest land to the plan.

Under the Government's guidance, the Ministry of Industry and Trade coordinated with provinces to review hydropower development planning and excluded 8 terraced hydropower projects, 472 small hydropower projects and 213 potential locations for hydropower development from the development planning.

Eliminating hundreds of hydroelectric projects

In the power source structure of the current national power system, hydroelectricity accounts for a large proportion. The latest report on hydroelectricity from the Department of Electricity and Renewable Energy (Ministry of Industry and Trade) said: In the national power system, hydropower projects in operation account for about 40% of installation capacity and about 37% for electricity, making an important contribution to ensuring energy security.

Regarding the terraced hydropower planning on big rivers, the Ministry of Industry and Trade said that 88 projects have been operating (16,123.9 MW); 15 projects are under construction (1,012.7 MW); 13 projects are under research (1,612.5 MW); and 3 projects (128 MW) have not been studied for investment.

For small hydropower planning, data from the Ministry of Industry and Trade shows that 342 projects have been operating (with a capacity of 3,582.66 MW); 158 projects are under construction (2,122,75 MW); 300 projects (3,121.65 MW) are under investment research; and 69 projects have not been studied (622.8 MW).

In addition, the Ministry has continuously checked and reviewed hydropower projects under guidance of the National Assembly's Resolution 62.

According to a report from the Ministry of Industry and Trade, the review of planning, construction investment and operation of hydropower projects in the country has basically been completed, meeting requirements in accordance with Resolution 62 of the National Assembly.

Based on the review in eight consecutive years (from 2012-2019), the Ministry has coordinated with provincial governments to consider removing from the planning eight terraced hydropower projects, 471 small hydropower projects, and 213 potential locations for hydropower development.

The construction of hydroelectricity plants also affects the area of natural forests. According to current regulations, the investors must replant forests to cover the natural forest area used by hydropower projects.

According to statistics from the General Department of Forestry (Ministry of Agriculture and Rural Development), as of September 2019, hydropower projects occupied about 30,305 hectares of forests nationwide. So far, the forest area planted to compensate the lost natural forests totals 33,735ha, reaching 111.3%.

The Ministry of Industry and Trade said that through inspections, it found that most investors of hydropower projects have strictly observed the reforestation work as required by the National Assembly and the Government. For those who fail doing this task, the Ministry will consider revoking the electricity license in accordance with the Government's resolution No. 11/NQ-CP.

Regulating operation of reservoirs

The role of hydroelectricity in the national power system throughout the years has been undeniable. This is an energy source that is considered renewable, and many developed countries classify hydroelectricity as renewable energy. However, before and during each rainy and flood season, the question "whether hydroelectricity cause floods" is raised.

"I disagree when someone says hydroelectricity causes flooding," said Dr. Nguyen Thanh Son, former director of Song Hong energy company. "Since the Qin Shi Huang dynasty, China has ruled over water by digging lakes. Nowadays, in addition to irrigation lakes, there are also reservoirs."

"So hydroelectric reservoirs are beneficial. For example, with Hoa Binh hydropower reservoir, the target set out is to serve irrigation purpose, i.e. give priority for irrigation, not electricity," said Mr. Nguyen Thanh Son.

Although he said that the floods were not caused by hydroelectricity, Son also had to mention another aspect. It is a matter of human regulation.

"In some cases, floods are caused by humans' regulation of reservoirs. The reservoir is not full yet, but local authorities ask to discharge water," said Mr. Nguyen Thanh Son.

He pointed out an example in which a hydroelectric reservoir can retain water of 1m more, but the local government asked to discharge water. If the local government regulated reservoirs well, the level of floods would have been limited, he said.

Supervising the operation of reservoirs

In fact, in the process of operating the hydropower reservoir, not all investors and localities have fulfilled their responsibilities. In a recent report responding to the National Assembly's questions about the field of industry and trade, the Government named a number of hydropower projects that do not comply with regulations.

For example, the Ministry of Industry and Trade unexpectedly inspected the operation of Dak Kar hydropower project in Dak Nong province and detected this project's violation in the field of natural disaster prevention. The case has been handed over to the authorities of Dak Nong province for handling.

Similarly, after detecting violations at the Su Pan 1 hydropower reservoir in Lao Cai province, the Ministry of Industry and Trade cooperated with the Lao Cai Department of Industry and Trade to impose a fine of VND120 million on the plant operator. In this case, the operator was fined for discharging water without informing local government and local residents in a timely manner.

Source: https://vietnamnet.vn/en/feature/floods-climate-change-and-hydropower-684975.html