HCMC flood-prevention plans a leaking sieve, experts say

By Huu Nguyen   May 30, 2018 | 03:30 am PT
HCMC flood-prevention plans a leaking sieve, experts say
Motorbikes break down on a flooded street in Ho Chi Minh City during a downpour on May 19, 2018, a few days after the city enter the six-month rainy season. Photo by VnExpress/Quynh Tran
No matter how much money is poured in, outdated urban drainage plans will ensure failure.

Flooding has haunted Ho Chi Minh City for almost two decades and there is no let up despite billions of dollars sunk into prevention efforts.

Without a sea change in current flood-fighting efforts, this situation will continue, experts warn, explaining that the drainage plans being used are outdated.

Vu Hai, an engineer with more than 50 years of experience in water supply and drainage, said that with its current methods, HCMC cannot fight flooding and has to change everything it is doing right now.

He said that for water drainage, the city is using a plan that was formulated by the Japan International Cooperation Agency in 1997-1998 and approved in 2001 (with vision until 2020).

This plan is no longer suitable as there are just three years left and the city has carried out less than 30 percent of its tasks, he added.

Aside from outdated data, the plan does not incorporate solutions for tidal flooding, sea level rises caused by climate change, and subsidence triggered by excessive groundwater extraction, he said.

For flooding, the city is using a plan developed by the agriculture ministry, which was approved in 2008.

But this plan only focuses on tidal flooding and fails to take heavy rains and dam releases into consideration.

And in a revised master plan for development until 2025 that was approved four years ago, the city has a plan to deal with rainwater and wastewater but not tidal flooding.

“What the city needs to do now is make a digital map for all of its current water drainage systems. This will work as a very important document, an effective tool for the management, design, construction and planning of the city’s drainage system, and it can also help with forecasting flooding levels in the future,” Hai said.

Since 2015, HCMC Steering Center of the Urban Flood Control Program (SCFC) has collected data for this digital map but it has limited this to downtown districts. Hai said the city should finish data collection within this year.

In the long run, a scientific council should be established to appraise designs of flood prevention projects and put them up for auction to lure private investors.

“If the city assigns the task exclusively to state organizations as it does now, no one can be blamed when some projects do not work effectively,” he said.

Ngo Viet Nam Son, an architecture specializing in master plans, said it is high time that the city faces the truth that its flood prevention projects so far have met with very limited success.

The flood fight can no longer depend on just dykes, sewers or reservoirs, because some high areas are still getting flooded due to the high density of concrete buildings that leaves no space for water to get escape.

“Preventing flooding requires a comprehensive, multidisciplinary strategy; but the city has been doing it sporadically and has stopped at coping with flooding rather than tackling it once and for all. This way, flood waters will only flow from one place to another,” Son said.

He suggested that the city appoints someone to take charge of flooding and traffic jams. Right now, just one person, the vice chair of the municipal People’s Committee, takes care of urban development in general and there are too many tasks for him to handle.

Son also said that it is irresponsible to blame the SCFC for a flooding problem caused by inadequate master plans, urban management, traffic, and construction also.

The city plans to build at least seven new wastewater treatment plants from now until 2020 to deal with its rapidly rising population, which has reached 13 million.

Ho Chi Minh City is vulnerable to flooding, and many of its streets are transformed into small rivers almost every time it pours or the tide rises. According to local media, the city will need VND97.3 trillion ($4.38 billion) for flood prevention projects over the next three years.

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