The 'mystery' behind the flooding situation at Vinh market

The boat dock disappeared.

Every time it rains heavily for several days in a row, the Vinh market area (Nghe An) is seriously flooded, greatly affecting the business and lives of small traders and residents here.

During the recent record flood from October 16-17, 2019, water rose to the roofs of kiosks outside the market hall, in some places the water level rose nearly 2 meters, especially in the area behind the West Hall of Vinh Market, causing billions of dong worth of goods of small traders to be damaged and swept away by the flood.

At that time, only the authorities could help the people. "The water was like rolling waves, making it difficult to walk," said Vo Thi Nhung, a trader at Tay communal house in Vinh market. After the rain, hundreds of traders' stalls turned into trash, causing billions of dong in damage. When provincial leaders came to survey Vinh market during the recent flood, they also had to use a motorboat.

Water flooded up to the roofs of kiosks outside Vinh market. Photo: PV

"Mystery" behind the flooding situation at Vinh market?

It is known that the old Vinh market was a bustling place with boats and wharfs, but this was also the lowest area of ​​Vinh city.

Mr. Bui Duc Loc - former Chairman of the Board of Directors of Vinh Urban Infrastructure Development Management Joint Stock Company, who understands quite well the principles of drainage in the city, said: In addition to the recent heavy rain, we must consider where the downstream drainage of Vinh market is?

Accordingly, the downstream drainage of Vinh market area is Vinh river, Lam river. Previously, to drain flood water for Vinh market before flowing into Vinh river, there was a boat lock containing water in front of Vinh river outlet like all the boat locks at other pumping stations.

Unfortunately, this boat lock (actually a lake) was completely filled in when implementing the Lung Lo urban area project. The investor, Lung Lo Company, replaced the boat lock with an underground ditch 3m wide and 2m deep to drain water from Vinh market to Vinh river (equivalent to the aperture of a level 1 ditch).

The old boat lock containing flood water for Vinh market is now an urban area and has been replaced by an underground ditch only 3m wide and 2m deep to lead water to Vinh river. This is considered the main reason why the drainage of water in Vinh market area is ineffective. Photo: PV

However, the disadvantage of this ditch is that when the Lam and Vinh rivers rise, the water in the ditch cannot flow into the Vinh river because the elevation on one side is lower than the other; the water flows more slowly, even flowing back into the Vinh market area. And together with water from other places such as Quang Trung, Cua Nam, and Hong Son wards, the water in the Vinh market area rises even more, causing flooding.

Not only has the boat lock "disappeared", the entire former downstream of Vinh market is now Long Chau and Lung Lo urban areas, with high-rise buildings built close together, leaving no room for the water flow.

Observing the manholes on the road where people removed the ditch covers, we saw that the garbage underneath had not been collected and cleared even more than 10 days after the flood.

Garbage filled the sewer of Vinh market. Photo: PV

Another reason is that in Vinh market area, there are many warehouses and garbage, the cleaning is often delayed, leading to the situation that when water flows in, the garbage blocks the drainage pipes, causing little water to drain, causing severe flooding.

What is the solution?

Mr. Bui Duc Loc added: Preventing flooding in Vinh market is very difficult even if the Vinh market level is raised. Because even if the Vinh market level is raised, the underground ditch is still lower than the Vinh river level, so the water still flows slowly or flows backwards.

Therefore, it is necessary to plan an additional forced pumping station for the Vinh market area with a capacity of about 15,000 - 20,000 m3 or more. And when this pumping station is available, it is necessary to have a boat dock to store water for the pumping station to operate; in other words, it is to "give back the name to me" for the ponds and lakes that used to exist in Vinh market.

When the Vinh River water level rises, the drainage of water from Vinh Market is completely ineffective because the drainage ditch is much lower than the Vinh River. Photo: PV

According to information, currently, Japan's Jica has come to survey Vinh market to find a comprehensive and long-term solution to prevent flooding in this area.

Mr. Tran Ngoc Tu - Chairman of Vinh City People's Committee also said that the city is holding a competition to design flood prevention for Vinh market area to find the most optimal solution, especially the areas around the main temple to prevent flooding for Vinh market in particular and the surrounding area in general.