Can Tho (VNS/VNA) - Land subsidence is worseningin the Cuu Long (Mekong) Delta, and experts told a recent seminar in Can Tho citythat over-exploitation of groundwater is one of the factors causing it.

Do Duc Dung, head of the Southern Institute of WaterResources Planning, told the seminar organised by Can Tho University andUtrecht University of the Netherlands to discuss groundwater planningand use and prevention of land subsidence that many studies have shown twoto four centimetres of subsidence occurs in the delta each year.

“The increasing speed of land subsidence is threateningthe future of the delta.”

The delta is facing challenges caused by decreasingsedimentation, illegal sand mining, riverbank and coastal erosion, anddegradation of freshwater resources, he said.

It is forecast that 60 percent of the Ca Mau Peninsula wouldbe below sea level by 2025, he said.

“To reduce land subsidence, all provinces and cities in thedelta need to carefully manage the use and exploitation of groundwater.”

It is necessary to switch to plants and livestock that do notneed much water, and dredge rivers and canals to increase storage offreshwater, he added.

An expert from Utrecht University saiduncontrolled exploitation of groundwater could lead to greater riskof saltwater intrusion in the delta in the future.

A study found that 1.9cm to 2.8cm of land subsidence occursin Ca Mau province every year, he said.

Ung Van Dang from the Soc Trang provincial Department ofAgriculture and Rural Development said his province has 107,000 wells for dailyuse and irrigation.

The current groundwater exploitation in the province isestimated at 243,000cu.m per day, he said.

Since 2017 groundwater has been decreasing significantly, hesaid.
To address the problem, the province has tightened theissuance of licences to exploit groundwater based on scientific waterresource protection measures, he said.

“It should increase the use of surface water anddevelop new water sources to reduce the use of groundwater.”

As long-term solutions the province is installing a networkof monitoring stations, he said.

The adoption of water-efficient irrigationmodels and implementing action plans to improveefficiency in water use are also needed, he added.

In a related development, the People’s Committee of Ca Mauprovince plans to relocate around 6,700 families living in erosion-prone areasalong rivers and canals to safe areas by 2025.

They are mostly in coastal areas in U Minh, Tran Van Thoi, PhuTan, Nam Can, Ngoc Hien, and Dam Doi districts.

Of them, more than 1,000 households lost their houses toerosion and are living in shelters or other people’s houses, and authorities inthe southernmost province will give priority for relocating them.
Besides, more than 3,000 others live in areas facing dangeror extreme danger of erosion.  

More than 2,700 families live along rivers and canals thathave a history of erosion or in flood-prone areas, and need to be relocated in2020-25.

The cost of the relocation is estimated at more than 940billion VND (40.5 million USD).

The province People’s Committee has asked the Government to prioritiseallocation of funds for the task.

Ca Mau has more than 254 kilometres of coast with hundreds ofestuaries.

To Quoc Nam, deputy director of its Department of Agricultureand Rural Development, said the east coast is eroding at a rate of 50 – 80metres a month since it does not have a protective dyke.

Last month the People’s Committee said severe erosion alongrivers, canals and coasts means more than 25 kilometres of coast and 1.2kilometres of rivers and canals require urgent protective measures.

It also decided to expeditiously build embankments to preventerosion at Rach Goc and Hoc Nang estuaries in Ngoc Hien district and Ho GuiEstuary in Nam Can and Dam Doi districts.

The province has lost nearly 9,000ha of protective forestssince 2007./.