How did Fukuoka fix that massive hole in just a week?

On November 8th 2016, a massive sinkhole appeared at a bustling intersection in Fukuoka, a Japanese city. Repair work was carried out swiftly, and just a week later, the hole was filled, the sections paved, and road lines painted. GovInsider caught up with Soichiro Takashima, Mayor of Fukuoka city to find out how the city pulled off the repair work in such a short time.

How did city officials coordinate its repair efforts?

The chasm appeared on the early morning of November 8, 2016. The upper part of the subway tunnel were partially destroyed and there was abnormal water flow.

When signs of the sinkhole appeared, workers on site urgently decided on their own to evacuate the site to the ground and stop traffic on the road.

After the sinkhole opened up, the city promptly contacted related parties and made initial responses, including shutting off the gas supply to prevent fire caused by gas leakage and bypassing the sewage discharge to prevent sewage from flowing into the sinkhole.

Due to these responses, no one was injured. If we had left the cave-in as it was, it could have been bigger, causing secondary damages and building up citizens’ anxiety.

We needed to repair the sinkhole and recover the grids as soon as possible so citizens felt safe. After discussing with related parties, we decided to fill up the sinkhole with liquefied stabilised soil at 10:00 a.m., and started the repair work at 2:00 p.m.

This happened on the same day, only 5 hours and 9 hours after the incident occurred. Next day on November 9th, we discussed with companies in charge of grid and pipeline restorations and agreed to have repair works carried out in two stages in order to achieve rapid recovery.

We also agreed to set a target of completing the work to reopen the road in one week. In the first stage - since the procurement of specially ordered pipes would take time - temporary pipes were installed for tentative reopening, serving as substitutes.

In the second stage, they would be replaced by specially ordered pipes for a full-fledged recovery. I joined the meeting and asked related private companies for their cooperation for the earliest recovery possible.

What were the challenges faced in coordinating such a quick repair work?

We had to use a special soil that could solidify in water and get dug out easily. However, since the scale of the cave-in was so big, a huge amount of the special soil was needed.

As there is a limit to how much soil can be produced and the soil hardens in a short period of time, it was a challenge to carry it from a faraway production site.

Under these circumstances, many companies came together to help regardless of their business rivalry and belonging to different group companies, and thanks to their generous cooperation, the necessary amount of soil was procured.

In order to recover the grids, it was necessary to have multiple workers in charge of utilities like gas, electricity, waterworks, sewerage, and communication engage another in repair works. Such a work process was unprecedented, and I truly appreciate their hard works and supportive attitudes to make it possible.

While we were aiming for the quickest repair possible, we thought safety should remain as our top priority. After setting the one-week target of recovery, I asked on-site workers to have the courage to stop their work if they catch any abnormal sign, and that I would truly appreciate it if they do so.

Every day, I asked them to be frank with us and share their concerns on what they noticed as unusual. I tried to create an atmosphere in which they could easily talk to us.

What advice would you give to other governments facing a similar issue?

When an accident or a disaster takes place, it is important for both public and private sectors to work together to recover safety of the affected area, for the sake of our community.

A top leader needs to go to the affected area to convey his/her feeling to workers on site and ask for their cooperation. It is also important to send information to make citizens feel safe and secured.

The city government provided every piece of necessary information to citizens. I also used social media to send more practical information that I thought citizens would want to know to ease their concerns.

What are your priorities for 2017?

Over the past several years, the economic performance of Fukuoka has been strong.

The numbers of tourists and calls for cruise ships are in a record high, and the amount of companies advancing into Fukuoka’s market has been growing. With such a robust economy, the city’s tax revenue has marked the largest ever increase.

I want to take advantage of these and bring Fukuoka to the next stage. One example of boosting our city infrastructures is a project to rebuild 30 office buildings in the city center within the next ten years.

Another project we have been promoting involves renovating our waterfront district into a focal point for cruising tourism, MICE (Meeting, Incentive, Convention, & Exhibition) and a place where people can enjoy the bustling surroundings.

A new urban development project is underway on a 50 hectare land, which is close to the airport and a subway station. By implementing innovative technology, such as IoT and self-driving vehicles in this area, we want to create a smart, sustainable and most advanced urban space in the world.

While Japan struggles with its ageing demographic and low birth rate - causing a sense of stagnation - Fukuoka has been growing in terms of population and economy.

Taking such advantages, I will continue to commit myself to Fukuoka’s urban development, toward a brighter future.