The HCMC Steering Center of the Urban Flood Control Program has proposed the municipal government execute a project to build underground antiflood reservoirs using Crosswave technology at flood-prone sites in HCMC, Nguoi Lao Dong newspaper reported, citing Nguyen Hoang Anh Dung, deputy director of the center.

Workers install an underground water reservoir on Vo Van Ngan Street in HCMC’s Thu Duc District. HCMC may develop a series of underground reservoirs this year to fight heavy flooding 

The proposal was based on the results of the pilot operation of an underground reservoir on Vo Van Ngan Street in Thu Duc District in August 2017, Dung said, adding that Crosswave is a water-holding material for rainfall accumulation and has mechanical durability. It is easily installed and uninstalled.

In addition, Crosswave technology can be applied to small and narrow sites, while the water storage space can be as high as 95% and remains environmentally friendly. After the construction of the reservoir, any given point on the surface can handle a vertical load capacity of 25 tons.

Following the trial operation of the Vo Van Ngan water reservoir, the center held a meeting and received a positive assessment of the effectiveness of the reservoir. In particular, prior to the installation, the street had repeatedly suffered heavy flooding, triggered by rainfall of up to 30 millimeters. After the reservoir was installed, only rainfall of up to 60 millimeters could submerge the street, but flooding times and flood tides are declining.

Some sites proposed for underground reservoirs are Hoang Van Thu Park in Tan Binh District, Lang Hoa Park in Go Vap District, District 10's Tran Thien Chanh Park, the median strip of a section of Phan Xich Long Street in Phu Nhuan District, the precinct of the Ward 25 Police Office and the sidewalk of Alley 48 on Dien Bien Phu Street in Binh Thanh District.

These reservoirs using Crosswave technology are expected to have a capacity of 1,500-20,000 cubic meters, alongside pumping stations and waste collection systems. The project costs an estimated VND475 billion.

Leaders of districts where the reservoirs will be built said that the capacity of the districts was limited due to the application of the new technology, suggesting the HCMC Steering Center of the Urban Flood Control Program should propose the municipal government assign the center as the investor for the project to ensure efficiency in construction.

Ho Phuong, vice chairman of the Binh Thanh authority, said that the planned reservoir on the sidewalk of Dien Bien Phu Street was unfeasible as ongoing construction work in the area will affect the designed site for the reservoir.

Phuong also noted that Binh Thanh District proposed building an underground antiflood reservoir in a section between Dien Bien Phu Street and Alley 135 on Nguyen Huu Canh Street because the section is often heavily flooded by rainwater. In addition, the flood-prone site is beyond the antiflooding scope of Quang Trung Industry JSC which operates a massive water pump on the flood-prone Nguyen Huu Canh.

Apart from proposing the HCMC government appoint the center to develop the project, the center also suggested the city’s government assign it to work with the municipal Department of Planning and Investment to add to the list of 2016-2020 mid-term investments prior to its submission to the competent authority for approval.

Many experts pointed out that building reservoirs with Crosswave technology is an effective way to combat flooding when the number of flood-prone sites in the city is rising.

Under the 2019 antiflooding program, the municipal government asked the relevant units to speed up work on seven projects to handle nine sites prone to heavy floods triggered by rains. The roads to be upgraded with drainage systems are Mai Thi Luu Street in District 1, Huynh Tan Phat Street in District 7, Tan Phu District-based Tan Quy Street and Bau Cat and Truong Cong Dinh streets in Tan Binh District.

The city will develop 218 antiflooding projects costing a total of VND8 trillion, including 77 projects carried out since last year with a combined investment of some VND5 trillion. Of the figure, 47 projects will be newly developed and 94 others are preparing for construction, with total respective costs of VND2 trillion and VND819 billion.

This year’s priority will be given to controlling flooding in a central area and five spots in the north, west, south, north-east and south-east areas, covering 550 square kilometers and accommodating 6.5 million residents.

SGT