Saigon braces for more record tides this year

On Monday the Southern Hydrometeorological Center reported that the tide rose to 1.77 meters at the Phu An Station on the Saigon River and 1.8 meters at the Nha Be Station on the Dong Dien River.

This surpassed the previous high of 1.72 m set in 2017.

Former deputy head of the center’s forecasting department, Le Thi Xuan Lan, attributed the very high tides to strong winds last week that caused the water level to rise in estuaries.

She also pointed a finger at climate change.

Since 1999 tide levels have been rising consistently.

Lan said: "But this may not be the highest yet, because there are five more major tides to come this year. Of which at least one or two tidal peaks can come close to or break the recently established record."

Prof Nguyen An Nien of the Ho Chi Minh City Water Resources Research Association said the rising tides in HCMC and the Mekong Delta are due to climate change and rising sea levels.

Many provinces and cities in low-lying areas in the delta have seen record water levels. Many areas are inundated by high tides combined with upstream floods. In general, the southern region is characterized by low plains and large estuarine systems, and so is prone to be submerged by high tides.

Nien said: "Floods, landslides, droughts in the Mekong Delta are also a result of climate change."

Dr Le Trung Chon of the geology faculty at the Ho Chi Minh City University of Technology blamed land subsidence for the rising tide levels.

Bad urban planning and development have been the main causes of erosion, referring to the constructions done on fragile ground.

The higher tides are also caused by the rise in sea levels, but this might not be significant considering the annual rise is only two or three millimeters.

Dr Nguyen Bach Phuc, chairman of the Ho Chi Minh City Association of Consulting Science, Technology and Management disagreed with all of them, saying climate change could not have such a rapid impact on HCMC.

Between 1995 and 2010 the sea level rose by only two centimeters whereas the tide levels have risen by 20-25 centimeters, he said.

The swamps in District 7 and Nha Be, where the high tide was recorded. used to drain the city, but were filled up to build houses, he said.

"The heavy flooding is due to the fact we have killed these spots. The city made a mistake by urbanizing low-lying areas and filling up water drainage areas, and so it is increasingly flooded. If we kept fixing the flooding issues in bits like this, it will not matter how much money we put into it: it just won’t be efficient," Phuc said.

For years scenes of people wading through or getting stuck on flooded streets in motorbikes and cars during high tides and heavy rains have become common in Saigon.

A major part of the city is expected to be below sea level within 50 years, according to some predictions.

To combat the flooding caused by high tides, Chon said it is necessary to standardize input data for forecasting and preventing floods. He called for updating the entire database related to the city drainage system, especially in its urban part, based on which an anti-flood design could be created.

The city also needs to build anti-flooding sewers and ensure the public infrastructure it builds is suitable for its terrain and drainage system.

In the meantime it can make use of the Internet of things, big data and AI to develop a flood warning and control system, he said.