HCM CITY — The use of temporary reservoirs, which have been an effective remedy to prevent flooding for the past 10 years, is part of a water-supply project plan approved by the Prime Minister.
|A road in HCM City's Binh Tan District. Many roads in the locality were flooded recently due to heavy rain. However, the use of temporary reservoirs has reduced the flow of water.— VNA/VNS Photo Hoang Hai
The reservoirs would be used if the city's main water sources, Dong Nai and Sai Gon rivers, become polluted.
Reviewing 10 years of flood-prevention efforts in HCM City, Tran The Ky, deputy director of the city's Transport Department, said flooding had reduced in three areas, thanks to reservoirs.
The February 3 street in District 10, for example, was one of the worst flooded in the city due to small drains.
However, since the city requisitioned Ky Hoa lake nearby as a temporary reservoir to store water for the area during heavy rains, flooding has dramatically diminished.
Other affected areas include Dam Sen Park in District 11 and the Phu Lam Roundabout in District 6.
The city has used the lake in the amusement park and a lake in District 6 as "water bags" to prevent flooding.
Now, the three areas have built bigger drainage systems, and the temporary reservoirs are no longer needed.
However, Tran The Ky said the reservoir was one of the city's most effective solutions to prevent flooding, especially in the context of worsening climate change, which has led to an increase in the number of heavy rains.
Because of the latter, the new drainage systems could become out-of-date sooner than expected.
According to Ky, the city's Anti-Flooding Programme Management Center is considering installing a reservoir in the Go Dua area in Thu Duc District.
The area, located along the bank of Sai Gon River with low terrain, is one of the city's worst flooded areas.
Saline intrusion stopped
For many years, Sai Gon Water Company (Sawaco), which supplies 80 per cent of water to the city, has had a contract with Dau Tieng Lake's Management Board to prevent salt-water infiltration.
Whenever Sai Gon River, the main water source of Tan Hiep Water Plant, becomes seriously infiltrated by salt water, the board allows the release of Dau Tieng Lake's water in order to get rid of the salt.
Sawaco reports that it uses Dau Tieng Lake five to seven times or more a year, mainly in the dry, hot season. Expenses are paid by Sawaco.
Similarly, Tri An Lake is specified in the water- supply project to 2025 as a solution for deep-water infiltration into Dong Nai River. This affects the source of the Thu Duc Water Plant.
According to the project, Dong Nai River together with the Tri An reservoir will supply 2.5 million cubic metres a day for the city.
According to Sawaco, the Thu Duc Water Plant, which is located far from the river mouth, has not needed the help of the reservoir because salt-water infiltration rarely occurs.
However, Sawaco regards the role of Tri An Lake as important.
The project is also considering installing pipelines from Tri An, Dau Tieng and Phuoc Hoa lakes to water plants.
In this manner, the lakes could be used as water sources in case the Sai Gon and Dong Nai rivers are heavily polluted.
The city is also considering the practicality of installing the Thu Khuc reservoir in Cu Chi District, which would be invested in by Hung Thuan Phat Investment and Development Co. Ltd. — VNS