Vietnam - Mekong Delta erosion: Is authorities' lack of determination to blame?
A boat carrying undercover officers from the Ben Tre Province environment police chugged along quietly along the river in Long Thoi Commune late one night in June.
They found a place to hide, stopped there, turned off all the lights, and waited in silence.
Then they suddenly started their boat to chase after three wooden boats and two steel vessels carrying sand, which was later measured at more than 120 cubic meters.
The sand thieves loudly urged each other to jump into the river and disappeared under cover of darkness, leaving just one man aged around 51 years.
Such hunts for sand thieves are one of several measures taken in recent years by authorities in the Mekong Delta to try and save what is left of heavily exploited rivers.
Sand theft has been rampant in the delta to serve the huge and growing construction industry.
According to the Ministry of Construction, the annual demand is for around 130 million cubic meters of sand while the authorized supply is only 62 million cubic meters.
There is no data for the volume of sand mined illegally except from individual cases that are busted.
In one such case, An Giang Province deputy chairman Tran Anh Thu was arrested last month for allegedly taking bribes of VND1.2 billion (US$50,000) to allow a business to mine 3.2 million cubic meters of sand above its licensed 1.5 million cubic meters.
To safeguard the country's limited supply, in 2009 the government for the first time banned construction sand and only allowed businesses to export sand taken from estuaries.
In 2017 it imposed a total ban on exports of all types of sand.
But all this could be too late.
Marc Goichot, lead of the freshwater program at the WWF Asia Pacific, said erosions are the result of destabilization of the delta.
"They are the more visible part, they are the tip of the iceberg."
"Prior to interventions 20-30 years ago, there was a balance. This was compensated by sediment coming from the river. Now you have a reduction in sediment.
"You can see the upstream deposition like credit to your account. And then people take sand out for construction, and that is the debit in your account. And now we know that the stock is limited to less than 10 years. So if nothing is done to increase the credit, or reduce the debit, then there will be a crash."
Dr Nguyen Nghia Hung, deputy head of the Southern Institute of Water Resources Research, said one reason for the delta's sand crisis is that there has never been a calculation of its actual supply, a task that is beyond the technical and financial prowess of local provinces.
The World Wildlife Fund Vietnam is trying to address this with its Sustainable Sand Mining Project (2021-2024), which aims to establish "a delta-wide sand budget to create a better understanding of the scope and impact of unsustainable extraction rates."
Ha Huy Anh, national manager of the project, said it "will prevent the Mekong Delta’s balance of sand from getting further in the red, and help us pay some debt to the river."
He said the project is expected to reduce riverbank and coastal erosion, salinity intrusion and high tides.
To protect the Mekong Delta from erosion and other kinds of environmental degradation, the government has spent nearly VND11.5 trillion (US$479 million) since 2016 building anti-erosion works that stretch 246 km long.
Another VND4.77 trillion is going to be used to build more riverbank and coastal embankments in the near future.
But these efforts have not stopped erosion.