Salty water in Bangkok is new ‘reality’ as sea pushes farther inland

Thai authorities are exporting drinking water to parts of Bangkok and advising people to shower less as worsening drought and rising sea levels have increased salinity, an increasing danger facing many Asian cities, climate researchers said.

The water authority of Bangkok said the capital’s tap water was becoming salty as seawater pushed up the polluted Chao Phraya River, a source of much of the water in central Thailand.

Prime Minister Prayuth Chan-ocha this week has been asking the public to save water by taking shorter showers.

Further make matters worse, the dry season in Thailand began in November and usually lasts through April, but officials said this year that it could last until June and that drought has been declared in 14 provinces.

According to Suppakorn Chinvanno, climate expert at Chulalongkorn University in Bangkok, the drought conditions have exacerbated the intrusion of saltwater which can have major impacts on farming and health as drinking water is contaminated.

“It is becoming a more serious issue, with the intrusion coming farther inland this year and earlier in the season,” he told the Thomson Reuters Foundation.

“It will have a serious impact on agriculture in the region, as rice is a very water-intensive crop,” he said.Many of Asia’s biggest cities, including Mumbai, Shanghai, Bangkok, Ho Chi Minh City and Jakarta, are coastal and low-lying, making them vulnerable to rising sea levels and extreme climate events such as more frequent and deadlier cyclones.

Bangkok is controlling groundwater extraction but is suffering from subsidence, making it more vulnerable to sea- level rise.

Diane Archer, research fellow, Stockholm Environment Institute

Indonesia is planning to move its capital to Borneo Island as Jakarta, on Java Island’s northern coast, is slowly sinking and undergoing regular flooding.

Cities located in deltas are increasingly confronted with saltwater intrusion, said Diane Archer, a research fellow at Bangkok’s Stockholm Environment Institute.

“The reality of climate change and the rise in sea level means that this is becoming increasingly a problem for delta cities as sea water intrudes into rivers and aquifers, particularly during drought and where groundwater is already exhausted,” she said.

“Bangkok controls the extraction of groundwater but suffers from subsidence, making it more vulnerable to rising sea levels.

Elsewhere in the Mekong Delta, saltwater intrusion is already a problem, with some cities in Vietnam monitoring salinity levels to alert farmers on whether the water is safe for irrigation, Archer said.

“Farmers may need to adapt their crops to those more suited to brackish water,” she said.