Flood discharge at Ban Ve Hydropower Plant: Responding to all situations

(Baonghean) - Ban Ve Hydropower Plant is a project of great significance in economic development and flood discharge regulation. Although since its operation, Ban Ve Hydropower Plant has never encountered any problems with flood discharge, after each rainy season, the Board of Directors and the Company's Flood and Storm Control Command have systematically conducted lessons learned, remedial measures, and drills.

Ban Ve Hydropower Plant is about 20 km upstream from the confluence of the Nam Mo River with the Ca River. The basin area up to the headwaters of the Ban Ve Hydropower Project is 8,700 km2, of which 7,080 km2 is in Laos, accounting for 80% of the basin area. The main construction area of ​​Ban Ve Hydropower Plant is located in Yen Na Commune, the reservoir area is located in the communes of Tuong Duong and Ky Son. With the task of supplying electricity to the national power system with an installed capacity of 320 MW, a guaranteed capacity of 90 MW, an average annual electricity output of 1,084.2 million kWh; participating in preventing minor floods, reducing early-season floods for downstream areas; creating additional water sources for downstream areas in the dry season, water regulation to both create energy sources and ensure flood prevention is the key issue.

Flood discharge during the rainy season at Ban Ve Hydropower Plant.

Engineer Nguyen Van Ngoc - in charge of hydrology, member of the Flood and Storm Prevention Command Board (PCLB) of Ban Ve Hydropower Joint Stock Company said: Because the terrain of this area is very steep, in the flood season, water accumulates quickly, in the dry season the flow is depleted, especially small streams often dry up for many days, causing a shortage of domestic water for people in the highlands. The average rainfall in the Ban Ve Hydropower basin is 1,788mm. Through monitoring, in the main flood season of 2013, on the rivers in Nghe An, there were 6-8 floods. Therefore, we pay great attention to the work of monitoring hydrology, monitoring storms and floods and making plans to prevent and control floods and storms close to reality. Before each flood season, the Company's Flood Control Steering Committee, in coordination with local authorities, carefully inspects flood discharge equipment and hydromechanical equipment systems such as: dike foot cranes, water intake gates, sluice gates, factory discharge gates, downstream dike foot cranes, spillway dike foot cranes, arc valve gate lifting systems, spillway repair gates, etc. In addition, the main power supply systems, backup power systems for flood discharge project gate operations, self-contained power supply systems, 35kV AC voltage systems taken from the local grid, etc. are all repaired, maintained, and operated normally. During the flood season, communication systems, telephones, loudspeakers, sirens, etc. are all checked to operate at their best.

Based on the flood discharge plan approved by the Ministry of Industry and Trade, Ban Ve Hydropower Plant has predicted possible dam safety situations and handling plans. If there are situations such as loss of all power supply from the factory's self-use power system or from the grid, after receiving the news, the Head of the Flood Control Command Committee will proceed: Order the factory shift leader to run the Diesel generator in automatic mode to supply self-use power to the factory.

If the flood situation is large, the lake water level rises quickly, the spillway's spillway gates need to be opened to discharge the flood, but during the process, one gate gets stuck and cannot be raised. The solution is to mobilize technical staff from the repair workshop with materials and equipment to the scene of the incident to measure and assess the equipment condition; Mobilize the generator to generate at maximum capacity, open the remaining gates at appropriate openings; Meet to assess the hydrological situation, assess the current status of the equipment and propose solutions; Report to the Ministry of Industry and Trade, the People's Committees of Nghe An and Ha Tinh provinces, the Steering Committee for Flood and Storm Prevention and Control and Search and Rescue of Nghe An and Ha Tinh provinces, Vietnam Electricity, notify Khe Bo Hydropower Plant and people upstream and downstream of Ban Ve Hydropower Plant for timely coordination and response when necessary.

If the hydrological situation worsens (flood flow ≥ 7770m3/s), the flood discharge through 5 sluice gates is not guaranteed, report to the Ministry of Industry and Trade, People's Committees of Nghe An and Ha Tinh provinces, Steering Committee for Flood and Storm Prevention and Control and Search and Rescue of Nghe An and Ha Tinh provinces, Vietnam Electricity Group, notify Khe Bo Hydropower Plant, local authorities to relocate residents in dangerous areas... The above are just possible situations for a project that has a large impact on flood discharge like Ban Ve Hydropower Plant.

Every year, Ban Ve Hydropower Company reorganizes the unit's Flood and Storm Control Committee, headed by the company's Director. In addition, the company also established a Flood and Storm Control Team of Ban Ve Hydropower Company, consisting of 106 employees, to respond to and quickly handle situations that may arise during the rainy and stormy season. Preparations for supplies, spare materials, tools, equipment, motorbikes, food, and medicine are fully prepared.

The Company also has a Regulation on coordination of flood prevention and control for Ban Ve Hydropower Plant between Ban Ve Hydropower Company and the Steering Committee for Flood Prevention and Control and Search and Rescue of Nghe An Province, People's Committee of Tuong Duong District, North Central Region Hydrometeorological Station, Nghe An Radio and Television Station, assigning specific tasks to each party and each unit. Accordingly, the responsibility of Ban Ve Hydropower Company is to operate the reservoir in accordance with the process approved by the Ministry of Industry and Trade. Best preparation for flood discharge and best response plans for situations. The Company also conducts full drills before each rainy season.

Thanks to the attention paid to flood control work, there have been no incidents in the downstream area over the past several stormy seasons. However, flood control work at the Ban Ve Hydropower Plant still needs to be paid attention to, invested in and monitored to avoid unwanted incidents, especially investing in flood control plans for the downstream area when there are two other hydropower plants below the Ban Ve Hydropower Plant.

Article and photos:Pearl