Salinity intrusion menaces southern region

Salinity intrusion menaces southern region

By Van Nam - The Saigon Times Daily

A boat transports drinking water for locals in the southernmost province of Ca Mau. Increasing salinity intrusion is adversely affecting livelihood as well as farming in the Mekong Delta - Photo: Van Nam

The salinity intrusion is pushing deeper inland due to dwindling water levels in southern rivers, including Saigon, Dong Nai, Tien and Hau. As the drought is predicted to last until end-April, the situation will surely be harsh, the source said.

Nguyen Le Hanh, deputy director of the Forecast Division of the Southern Region Hydrometerological Center, told the Daily on Monday that at the moment salinity intrusion has pushed at least 20 kilometers deeper into the basin of the Tien River compared to March of last year. The intrusion is reported seven kilometers inland in the basins of the Dong Nai, Saigon and Hau rivers.

Salt contents in fresh water sources are also reported much higher than year-ago levels, affecting both irrigation for farming and the supply of running water for cities and towns in the south, Hanh said.

The salinity level at Saigon-Nha Be Station along the Nha Be River has increased slightly from 13.7grams a liter in March last year to 13.9 grams now, but at Ben Luc Station in Long An Province, the content has increased from 2.9 to 3.9grams.

The salt content is even worse elsewhere, increasing from 2.4gr a liter to 5.9gr a liter at Phu Khanh Station, and from 3.9gr to 6.7gr at Tra Vinh Station, both on the Tien River. The level at Dai Ngai Station along the Hau River has also increased from 1.4gr to 3.0gr a liter, year on year, according to the forecast center’s monitoring results.

Such high salt contents make it impossible for processing the water sources into drinking water, as the permissible level under the World Health Organization is only 250 milligrams a liter.

“This is the worst salt intrusion in the region since 2006. However, the situation will get aggravated in the coming days because the rainy season this year will come late than last year,” Hanh said.

In HCMC, salinity intrusion is also accelerating in key water sources, though still far from the alarming level.

The HCMC Environmental Protection Agency has just monitored the salt level at six monitoring stations namely Ben Cui, Ben Suc, Thi Tinh, Phu Cuong, Hoa An and N46 Station to check the surface-water quality of the Saigon and Dong Nai rivers. Findings show the salt content has increased strongly, by up to three times at some places.

Nguyen Thanh Huy, vice head of the Monitoring and Environmental Assessment Division of the agency, told the Daily on Monday that “it is a big concern as the monitored results at Phu Cuong, Thi Tinh and Hoa An stations showed the salt level has increased by 2.3 times compared to January this year.” The local water supplier Tan Hiep Water Plant is taking crude water from these three stations for its tap-water processing.

Huy said the salt content at these three stations amounted to 89 milligrams per liter, and is poised to increase further due to the prolonged drought.

To dilute salinity in the lower section of the Saigon River, Dau Tieng Reservoir in the upper reach is discharging water with an amount of 4.1 million cubic meters in ten days from March 11 to March 21. This is aimed to help ensure the quality of crude water for Tan Hiep Water Plant and irrigational water for farming along the river basin.

Minister of Agriculture and Rural Development Cao Duc Phat late Friday had a meeting in Soc Trang Province with 13 provinces in the Mekong Delta to seek proper solutions for the worsening salt penetration and drought there, according to the ministry’s website www.agroviet.gov.vn.

The website said the salt penetration has been threatening some 30,000 hectares of paddy fields in Bac Lieu Province, while Ca Mau and Kien Giang provinces reported that the control of salinity intrusion was becoming difficult due to dwindling fresh water sources.