Da Nang: Dams built to deal with lack of fresh water

The central city has begun construction of a steel dam – the second of its kind – on the lower Cam Le River to reduce salinity and deal with serious water shortages in the dry season this year.

General director of the Da Nang Water Supply Company (DAWACO), Ho Huong, told Viet Nam News the project was urgently needed to solve serious saline intrusion this year.

He said the city would face water shortages this summer when the upstream flow was forecast to be lower between April and September.

Huong said the two temporary dams, which would cost a total of 13 billion VND (565,000 USD), would help the city collect enough fresh water to deed the Cau Do water plant.

He said the first 180m long dam, which was completed in late January, had helped reduce salinity in the river to less than 1,000mg of salt per litre – a ratio possible for fresh water collection.

The second dam, which started construction on Monday, would help lower the ratio to between 500mg and 600mg per litre.

According to the regional meteorological station, water flow from upstream would fall from 40 to 90 percent, and salinity would reach more than 6,000mg salt per litre – higher than the worst salinity recorded in 2019 (5,109mg per litre).

Meanwhile, the city has also upgraded the An Trach pumping station to collect enough fresh water to supply the city’s demand of 310,000cu.m each day.

Experts from DAWACO said the steel panel structure was used to deal with salinity in the Mekong Delta River, and could be rapidly deployed and removed.

Earlier this month, Da Nang asked management boards of the A Vuong and Dak Mi 4 hydro-plants to discharge water from their reservoirs to save the city from serious salinity that lasted 36 days.

Last year, the city’s water supply could only meet 70 percent of demand due to high salinity at the Cau Do water plant – the main source of fresh water for 1 million residents and tourists.

Water shortages in Da Nang have been occurring for several years now, resulting from deforestation, low rainfall and the operation of hydropower plants on the Vu Gia–Thu Bon river system covering Quang Nam and Da Nang.

Source: Vietnam News Agency