On March 30, Da Nang Irrigation Exploitation One Member Limited Liability Company issued an urgent report on the salinity intrusion situation on the Vinh Dien River. This development is directly affecting water supply for the winter-spring crop production at two pumping stations Cam Sa and Tu Cau.
According to records, from March 23, the salinity at the pumping tank of Tu Cau pumping station ranged from 0.9 to 5.6‰. At Cam Sa station, the salinity was from 0.9 to 3‰. This level often exceeds the permissible limit, forcing stations to stop operating for many hours each day.
Reality at irrigation areas shows great pressure on water sources. About 243ha of rice under the responsibility of Tu Cau station has dried up and has no water. Meanwhile, more than 107ha under the responsibility of Cam Sa station still retains moisture but poses high risks. Rice is entering the flowering to ripening stage, with very high water demand.
The additional water source from upstream also decreased. The discharge flow from hydropower reservoirs to the downstream Vu Gia - Thu Bon river on March 29 was only more than 24 million m3, a sharp decrease compared to before. It is predicted that the water shortage situation will continue, causing difficulties for irrigation pumping.
Another reason is the siltation of the Vinh Dien river mouth in the Cam Dong arch area that has not been dredged. This limits the flow from the Thu Bon River, causing the ability to push salinity to decrease.
Faced with the above situation, the irrigation management unit proposed to increase the discharge flow from upstream hydropower plants. The goal is to supplement water sources, push salinity, and ensure the operation of pumping stations in the late season.
At the same time, it is proposed to accelerate the construction of seasonal dams to prevent salinity, retain freshwater and dredge silted rivers. This is an urgent solution to stabilize irrigation water sources.
Previously, city leaders requested units to proactively plan to respond to drought, water shortage and saltwater intrusion. The work of monitoring and regulating water sources is strictly set out to minimize damage to production and life.
It is predicted that in the coming time, the risk of drought and water shortage will continue to increase. Synchronous coordination between sectors, localities and people's awareness of water saving will play a key role.
