Need to soon implement temporary solutions and flexibly operate lakes and dams

Da Nang City is exploiting 70-80% of the water source from Vu Gia River for production and daily life. At the beginning of the dry season, the water level of the rivers often drops locally for 1-2 days because the hydroelectric reservoirs on the upper Vu Gia - Thu Bon River discharge water at low flow rates on weekends... combined with storing water in the reservoirs to supply electricity during the peak of the hot season.

Besides the reason that Dak Mi 4 hydropower plant transfers almost all of its water resources during the dry season from Cai River (Dak Mi), a main branch of Vu Gia River, to Thu Bon River for electricity generation, the diversion of water from Vu Gia River to Thu Bon River is larger than the previous natural rate (20%) because the channel of Quang Hue River fluctuates complicatedly and has not been temporarily dammed, also causing a shortage of water for the downstream of Vu Gia River. At the same time, the dams of An Trach irrigation system, especially An Trach dam, have been degraded after 20 years of use and cannot hold much water when the water level of Yen River is low...

Along with that, the salinity of Cam Le River water increased to 600mg/l, the highest since the beginning of the dry season. This, along with a number of other reasons, caused the water level of La Tho River at the upstream of Thanh Quyt Dam (Quang Nam) to drop to 0.95m, 1.05m lower than the normal water level, making it impossible for pumping stations to operate normally to supply water to the flowering rice fields...

Regarding the degraded and damaged gates of An Trach dam, representatives of some related units said that it is necessary to have solutions to repair and overcome the above situation, combining flexible operation according to the actual situation to not let the water level of Yen river drop too low and not cause disadvantages to the pumping stations, and to regulate water to reduce salinity for the pumping stations downstream of the dam as well as Tuy Loan river.

Chairman of the Board of Directors of Da Nang Irrigation Exploitation Company Limited Nguyen Anh Tuan said that in 2024, the company had basically handled the water leakage through the gates of An Trach Dam. At the same time, it had sent a document requesting the city for funding to repair and replace gaskets, cables, etc. to serve the operation of the gates of this dam, but so far there has been no policy to implement it.

General Director of Da Nang Water Supply Joint Stock Company Ho Minh Nam said that, implementing the official dispatch of the City People's Committee on building a temporary dam on Quang Hue River in 2025 to increase water flow to the downstream of Vu Gia River, the company has prepared a design dossier for the plan to reinforce this temporary dam. The company has sent the design dossier to the City Department of Agriculture and Environment for review and comments for the company to soon complete the dossier as well as implement the construction when required to ensure safe water supply for the city in 2025.

In addition to solutions to ensure water resources for the Vu Gia - Thu Bon river basin, relevant units plan to build a temporary dam to prevent salinity at the end of the Hoa Lien flood drainage canal; increase the water supply capacity from the Hoa Lien Water Plant to the pipeline network when necessary; flexibly operate the discharge of environmental flows after the Nam My dam according to the hydrological regime to ensure the water level of the reservoir on the Cu De river for pumping stations to operate normally... to ensure the supply of water for daily life and production for the city.

NAM TRAN

Source: https://baodanang.vn/xa-hoi/202504/can-som-thuc-hien-giai-phap-tam-va-van-hanh-linh-hoat-ho-dap-4003202/