Filling up a well in HCM City’s Hóc Môn District. — Photo nhandan.com.vn

HCM CITY — The People’s Committee of HCM City is taking measures to restrict groundwater exploitation, which has led to increased water pollution, flooding and subsidence.

Many households and organisations have exceeded the permitted exploitation level, and the city now has an average subsidence rate of 4 centimetres a year, according to the Ministry of Natural Resources and Environment.

Tân Bình District’s An Lạc Ward, for instance, has subsided 81.4 centimetres over the past 12 years, the highest rate in the southern region.

The city aims to reduce the quantity of groundwater exploitation to 100,000 cu.m a day by 2025.

To protect groundwater, the city has been filling up wells that are damaged, unused or unlicensed. It has also encouraged households to fill up wells in areas where there is clean tap water.

In areas where the quality of groundwater does not meet standards, the city will encourage households to use tap water.

The city’s Department of Natural Resources and Environment plans to stop granting licenses to 151 groundwater exploitation works that belong to companies, industrial parks and export processing zones. These works exploit a total of 62,860 cu.m of water a day.

Along with construction projects built on weak land and transport activities, groundwater exploitation is one of the main causes of subsidence, according to the ministry.

Huỳnh Thanh Nhã, head of the department’s Water Resources, Mineral Resources, Sea and Island Division, said the overexploitation of groundwater had changed the level of underground water and geological structure.

The city has about 100,000 bored wells that exploit about 700,000 cu.m of groundwater a day, he said.

The wells belong to households, companies, industrial parks, export processing zones and the State-owned Sài Gòn Water Supply Corporation (Sawaco).

Many households which have access to tap water still use wells to save on water costs.

The city has about 1.46 million water metres, but about 124,500 water metres have zero consumption value, meaning the owners of the 124,500 water metres are not using tap water, according to Sawaco.

Sawaco’s water supply companies have increased investment in tap water networks and have encouraged households with access to tap water to fill up their wells.

Nguyễn Văn Nên, who lives on Lê Quang Định Street in Bình Thạnh District, said his family stopped using a bored well and switched to tap water after local authorities explained that overexploitation of groundwater was contributing to subsidence in the city.—VNS