Vietnam News Bridge – Questions are mounting following water discharged from the reservoir of Ba Ha hydro-power plant after typhoon Mirinae. The serious floods that followed covered a vast area, causing serious damages to Phu Yen province.

The Ba Ha hydropower plant (photo: VNExpress).

On November 2, when storm No. 11 or Mirinae hit the central province of Phu Yen, the reservoir of Ba Ha hydropower plant discharged water which doubled normal local levels.

That night, the Da Vai dam broke immerging Song Cau town and many areas in the Tuy An district of Phu Yen province. This incident killed many people and damaged Song Cau and Tuy An.

The local media has continued to question the decision to discharge the water.

Explanation

The Ba Ha power plant’s director Vo Van Tri confirmed that his company obeyed the water discharging procedures and reported to the local government its activities. Tri said discharging water at that time was necessary to prevent the reservoir from being “broken” by floods. He said if the reservoir was broken, the consequences may have been worse.

According to Tri, Ba Ha power plant is located in the lower section of the Ba Ha River so it cannot control floods with a reservoir of only 347.9 million cu.m. After typhoon Mirinae, all four other reservoirs on Ba Ha River discharged their water, causing a record high level of water on Ba Ha river. If Ba Ha hadn’t discharged its water, its reservoir would have been broken.

The Ba Ha River Hydropower Plant is located in Son Hoa district, Phu Yen province. Its reservoir contains 349.7 million cubic meters. The water volume running to the reservoir is between 5-7 billion cubic meters a year.

Tri said that the plant informed the local Steering Board for Flood and Storm Control about its plans to discharge water on November 2 to remove local residents from dangerous areas. The plant tried to discharge water gradually, at 600cu.m per second on November 1, 1200cu.m on November 2 and 6000cu.m per second on November 3, when floods were at an alarming level.

“In normal weather conditions, the flow of water discharged on November 1 and 2 would not affect the lower area. However, the discharge was at the time of downpour and flood tide so damage was unavoidable,” Tri said.

Tri complained that there is no mechanism for cooperation among five hydropower plants on the Ba Ha River, especially in discharging water. He said the company asked Phu Yen and Gia Lai provinces to combine to control the operation of reservoirs on Ba Ha River three months ago but the company didn’t receive reply yet. Ba Ha plant is located in the last section of the Ba Ha River so it is seriously affected by the discharge of water of other power plants in the upper stream.

The opinions of experts and officials

Duong Van Huong, who is in charge of irrigation in Phu Yen province, said the Ba Ha River Hydro-power JS Company didn’t breach the water discharging regulations. The company informed the local government of its water discharging plans in advance. “In such situation, even ten hydro-power plants like the Ba Ha River couldn’t stop the flood while it had to ensure the safety of the reservoir,” Huong told VNExpress online newspaper.

Deputy Minister of Industry and Trade Do Huu Hao said: “Nobody knows how much floods will be when typhoons come. It is unavoidable for hydropower plants to have to discharge water. In principle, reservoirs store water for generating power and discharge waters in floods.”

According to him, the public only sees one side – the discharging of water which caused serious flood. He argues that without reservoirs, which can at least store part of flood water, the floods would be more serious. However, if reservoirs try to hold all the water, then the reservoirs can break and water can sweep away a whole town.

Hao confirms that all hydropower plants are controlled and built under government specification. Besides generating power, hydropower plants must meet technical and environmental standards and ensure safety down river.

Deputy Prime Minister Hoang Trung Hai shares the same opinion with Hao, saying that the Ba Ha hydropower plant followed the procedures for water discharging.

Meanwhile, Vu Trong Hong, secretary general of the Vietnam Irrigation Association and former deputy minister of Irrigation, said that a hydropower plant should only discharge water after evacuating local residents. “It is unacceptable to discharge water and then say that it is unavoidable,” he said.

Hong said before the flood season, the Central Steering Board for Flood and Storm Control must define how to regulate water in a river, which has 3-4 hydropower plants. It is also necessary to map depressed areas to prevent flooding when reservoirs discharge water.

Prof. Dr. Pham Hong Giang, chairman of the Vietnam Great Dams and Water Resources Development Association, former deputy minister of Agriculture and Rural Development said that without clear management procedures for reservoirs, they can make “artificial floods” at the same time as natural floods.

He said that in the past, the Irrigation Ministry was in charge of planning and managing water resources. At that time, most small and medium reservoirs served agriculture. After that, hydro-power generation became the biggest concern as the need for more energy grew. When considering medium and big hydropower projects, the Ministry of Irrigation (now the Ministry of Agriculture and Rural Development) asked reservoirs to include the function of flood prevention.

“However, I don’t know how what functions are implemented,” Giang said.

He said only the Hoa Binh reservoir has government-approved operation procedures. The safety of Hoa Binh dam is also assessed annually by a joint-ministerial council.

“In some rivers, hydropower plants are built to a terraced model which takes full advantage of hydraulic power. Water discharge of the upper reservoirs affects the lower ones. However, there are no regulations managing terraced power plants. Recent floods that caused serious losses in the central region pose urgent matters, including the control of reservoirs,” Giang added.

Bui Cach Tuyen, the chief of the General Department of Environment said that the number of small and medium hydropower plants in the central region and the Central Highlands has reached 355, including 113 in Gia Lai province, 55 in Lam Dong, 22 in Kon Tum, 64 in Dak Nong and 101 in Dak Lak. He suggests local governments have a role to play in monitoring these work and looking to find a way of avoiding such losses again.

Nguyen Dinh Xuan, a member of the National Assembly’s Committee for Science, Technology and Environment, said the Ministry of Industry and Trade has to take responsibility for the incident. He has asked that an inspection group is set up to investigate hydropower projects in the central region.

PV