Thu Duc flooding triggers investigation, improvement plans

The persistent flooding at Thu Duc Market, exacerbated by its low-lying geography and outdated drainage systems, has led to significant disruptions. Comprehensive studies by local authorities and experts have led to the proposal of new drainage projects.

The market connects with many streets in Thu Duc City, such as Vo Van Ngan, Duong Van Cam, To Ngoc Van, Kha Van Can. This area was deeply flooded during the heavy rains on the two days of May 15 and 20.

Flood waters opened manhole covers, cracked roads and disrupted traffic and the daily activities of businesses and local residents.

A manhole cover on Le Van Ninh Street next to Thu Duc Market comes off, causing water to overflow during a heavy rain on May 20, 2024. Photo by VnExpress/Quynh Tran

Luu Trong Nghia, Head of the Public Transport Department of Thu Duc City, said the market is located in a transition area from the hilly terrain bordering Binh Duong Province to the lowlands along the Saigon River, with the altitude varying from 30 m down to 0.5 m.

The market area is lower than its surroundings and acts like a drainage basin that receives water from other areas totaling about 430 hectares.

This is also the reason why the recently completed drainage project on Vo Van Ngan Street has failed to resolve the flooding situation in the area, Nghia told a seminar on the current state of Thu Duc City flood prevention solutions on Friday.

The project, costing over VND248 billion ($9.75 million), was launched in mid-April.

Nghia said the project could only serve as drainage for an area of about 87 hectares.

Other drainage projects around the market, including those on Duong Van Cam, Dang Thi Ranh, Kha Van Can, Ho Van Tu streets, have not yet been implemented, leading to the recurrent flooding in the area during heavy rains, he said.

Le Song Giang, a lecturer at the Ho Chi Minh City University of Technology, also noted at the seminar that the Thu Duc Market area is like "lying at the foot of a hill," but it is not the lowest-lying area in its surrounding environs.

Thus, he said it had been city planning and development projects that were the major cause of the flooding problems.

Major traffic routes and drainage systems all lead to the market area, while the drainage system leading away from the market towards nearby Cau Ngang Canal had not been effective.

At the same time, rapid concretization has reduced permeability in the area, causing water to accumulate in drains, which results in water spilling out onto the roads in strong currents.

Giang said that in order to address the situation, Thu Duc City needs to immediately make plans to reduce water accumulation at the market area by increasing permeable surfaces, regulatory ponds, and diverting flows to other drainage areas.

Additionally, Giang said the ground levels of the market and the areas surrounding it must necessarily be raised, while the Cau Ngang Canal needs to be expanding, and new drainage systems need to be built towards the canal.

Other experts at the seminar agreed, pointing out that the Cau Ngang Canal – Thu Duc Market’s main source of draining – is only five meters wide and is currently clogged with garbage and a thick layer of sedimentation, both of which have reduced its flow.

Therefore, most experts agree that in order for immediate solutions to be implemented, Thu Duc City needs to clear the canal first.

Out of date, but big plans

Chau Nguyen Xuan Quang, deputy director of the Institute of Environment and Natural Resources at Vietnam National University, HCMC, said Thu Duc City’s drainage system has over the years been implemented according to outdated planning no longer suitable to current situations.

The city, which officially came into being in January 2021 as a "city within a city" under the administration of Ho Chi Minh City by merging Districts 2, 9, and Thu Duc, needs to update data and conduct a comprehensive study of the drainage system to meet new conditions.

This would be the basis for proposing new scenarios and suitable implementation solutions, he said.

Thu Duc Market is flooded during a heavy rain on May 20, 2024. Photo by VnExpress/Quynh Tran

Thu Duc’s Vice Chairman, Mai Huu Quyet, noted that while many parts of the city are situated on elevated terrain, there are also extensive low-lying areas with significant slopes, particularly around the Thu Duc Market area.

Additionally, he highlighted that drainage networks have either been neglected or have deteriorated from prolonged use without adequate investment.

Quyet said that the city’s first initial step will be to dredge both the Cau Ngang Canal and the drainage systems on roads surrounding the market to improve drainage capacity.

As for long-term solutions, he said the city would accelerate the implementation of new drainage projects around the market with a total budget of about VND70 billion.

In addition, the locality will then renovate Cau Ngang Canal at an estimated cost of about VND27 billion.

However, he noted that the most fundamental solution is a project to build embankments, renovate the Thu Duc Canal, which links with Cau Ngang, in combination with the construction of a pumping station along the Thu Duc Canal, with a total budget of over VND4.4 trillion.

He said the city would propose the project to HCMC authorities in hopes of expedited implementation.

Thu Duc City covers about 211 sq. km and is home to more than one million residents.

Currently, besides the Thu Duc Market, there are many long-standing flooding points in the locality, including the Thao Dien area, home to a large expat community.