Terrain that collects rainwater, asphalt that does not absorb water… Can’t stand heavy rain
It is not enough to complete the drainage division tunnel… Drainage area adjustment work delayed due to budget problems
Gangnam Station, a chronic flooding area in Seoul, was again submerged in record heavy rain.
Rainfall exceeding the treatment capacity is considered to be the biggest cause, but it is pointed out that the Seoul Metropolitan Government’s preventive measures were insufficient in a situation where localized torrential rain could be sufficiently predicted due to climate change.
According to the Seoul Metropolitan Government on the 9th, it rained more than 100mm per hour in Gangnam-gu and Seocho-gu since the previous day.
This figure far exceeds the maximum rainfall capacity of 85 mm per hour in the Gangnam area.
The Gangnam Station area is considered to be one of Seoul’s representative habitual flooding areas.
The land is lower than the surrounding area, and the water from the Seocho and Yeoksam highlands is a pot topography, and flooding was frequent due to the lack of water flow in the upper part of Banpocheon.
In particular, there was a lot of asphalt that could not absorb rainwater, and as rainwater was concentrated in the Seowun-ro sewer pipe, the manhole cover that could not withstand the pressure was opened, causing the sewage to flow back.
In September 2010 and July 2011, torrential downpours flooded the Gangnam area.
In response, the Seoul Metropolitan Government announced the ‘Comprehensive Drainage Improvement Measures for the Gangnam Station Area and Flooding Vulnerable Areas’ in 2015. ▲ Adjusting the boundary of the drainage area to correct the improperly installed sewage pipe ▲ Segregating the basin, an underground drainage facility that distributes rainwater from the Seoul Nambu Terminal to the middle of Banpocheon Stream tunnel construction, etc.
However, the project continued to be delayed due to budget and design issues.
The drainage area boundary adjustment project is a project to improve the rainwater discharge method by adjusting the boundary between the highlands that are higher than the river level and the lowlands that are lower than the river level. has been extended.
The Banpocheon Basin Division Tunnel (Gyodae Station – Express Bus Terminal Station, total length of 1,162m) started construction only in 2018 and was completed in June of this year.
Meanwhile, backflow of sewage occurred at Gangnam Station in August 2020.
With the completion of the separation tunnel construction, the ability to protect against rainfall at a frequency of 30 years (95 mm per hour) has been secured, but it is still helpless in record heavy rains like this one.
An official from Seoul said, “Currently, countermeasures have been prepared with the goal of responding to rainfall at a frequency of 30 years, but in order to respond to a heavy rain like this one, we need to raise the target for responding to rainfall in consultation with the government. .
/yunhap news