Urban flooding in Ho Chi Minh City, Hanoi and many other cities in Vietnam has become worse and worse after every rainy season. In Phu My Hung, however, that has not been an issue and will never be one if the master plan is strictly followed and environmental standards not violated.
The river, canals and ponds in Phu My Hung urban area were kept intact to reserve the scenery and avoid blocking natural waterways. Photo: Thanh Toan
There are various explanations for chronic urban flooding in HCMC. The major reasons, according to many, are high tide and the old and deteriorating drainage system, which was built during colonial era for a small population.
Widespread construction and the infilling of natural drainage has increased flood hazard in the city for the past few decades. A study showed that between 1989 and 2006, concreted area in HCMC increased to 24,500 hectares from 6,000 hectares. After almost 10 years, that figure is certainly much higher now.
In modern cities, rainwater management is a serious issue. Nguyen Minh Dong, an environmental expert in Germany, said rainwater management in that country has reach such a level that you would pay less tax if you had a ribbon driveway instead of a fully-paved one; or that you could pay less for running water if your house had a rainwater storage tank.
The master planners of Saigon South urban area made sure that the area itself would neither be flooded nor affect the city’s natural drainage. They even took into account sea level rise due to future climate change.
Accordingly, the permitted construction surface is 1.5 meter above the highest tide level. The river, canals and ponds in the area were kept intact to reserve the scenery and avoid blocking natural waterways. Large swaths of public land line both sides of the river as another defense line against flooding. Architect John Lund Kriken, head of master planning of Saigon South project, noted that the urban area was designed to make sure that all non-road surface could allow water to go through.
In fact, the PMH residential area has been developed as such.
Nguyen Buu Hoi, Vice General Director of PMH Development Company Ltd., told us that asphalt and concrete paving has been reduced to a bare minimum. A brick pavement system which allows rainwater to run through joints has been used, he said.
A brick pavement system which allows rainwater to run through joints has been used in Phu My Hung.
Some critics argued that since Nha Be District is the city’s “low land,” the rise of PMH residential area has negatively affected the city’s natural drainage.
As one who involved in the founding of Saigon South and PMH, Phan Chanh Duong called the argument a “fallacy.”
According to him, the planned area of Saigon South is 2,600 hectares, or less than 10 percent the area of Nha Be District. Meanwhile, the total area of PMH itself is just 600 hectares - less than 2 percent of the district’s area, of which only 299 hectares was developed. It is therefore impossible to say that PMH affected the city’s natural drainage, he said.
“On the map of Saigon South [urban area], you can see that PMH [project] does not block any canal or stream,” said Hoi. PMH residential area therefore had no negative impact on the city’s natural drainage and waterways, he claimed.
He pointed out that there are dozens of bridges along the 18-km long Nguyen Van Linh St., which also boasts a complete and well maintained storm drain system. As a result, while unusual heavy rains may inundate some parts of the street, the excess water will get off the street soon after.
Since road infrastructure in PMH was built on soft soils, it would need maintaining and strengthening for a few more years. That is something the blueprint designers of Saigon South planned in advanced and has been routinely carried out by PMH management.
The designers also warned against over-expansion of urban construction areas, in order to maintain an area of agricultural land and natural land to ensure an environmental harmony.
PMH Company has done its best to follow the master plan. If the rest of Saigon South were developed in strict accordance with the master plan, the infrastructure of the entire urban area would be consistently connected, which in turn would greatly benefit investors and residents alike. That would also help accelerate local growth and create a magnificent and environmentally friendly landscape for a future metropolitan.