― Learning from urban flood control measures

"I always thought that a control reservoir is outside. However, this giant space is located underground of the center of the city and keeps it from floods."
On the second day of the workshop, a participant from Seoul could not help saying so for the size of the reservoir as soon as he entered inside of the Meguro River Ebara Regulating Reservoir.
The reservoir is a large underground structure spanning four layers that was built to protect the city from the floods caused by overflow from the Meguro River. The participants went into the reservoir which can accumulate water to fill about 800 times of a 25-meter pool, and observed the structure from up close (of course the water was not released during the workshop).
"You can see an intake up there. The water will flow into ponds from there when the water increases to the levels that floods are possible to occur. Sometimes using one layer would be enough. If it is not enough, the water flows into next layers sequentially depending on the amount of rainfall."
The participants asked various questions in between explanation by the TMG officials:
"How do you drain the water from the ponds?"
"Doesn't ever garbage come with water? How do you clean it up?"
The participants seemed to try to learn as much as possible to seek if there were any projects that they could use in their own cities. It is becoming very difficult to secure the land for retention facilities especially in Bangkok where urbanization have been progressed rapidly. They seemed to get a new idea, from this aspect as well, towards introducing of underground retention facilities through this visit.
In between the enthusiastic question and answer session during the visit, a participant from Bangkok also said,
"It is not visible from outside but what actually supports this gorgeous and beautiful city is the facilities like this and people who manage them. It was a valuable experience to be able to see these facilities in person."
From the beginning, participants from Bangkok who had experienced serious flood damage in 2011 have told us that they would like to make the most of the workshop and learn measures by the TMG on how to accumulate rainwater. As officials in Asian major cities, they perhaps shared a sense of camaraderie with the TMG staff, who have worked on the common issues in Asia.

― Seeking a solution to the common problems through efforts for lowland rivers by Tokyo

Many of visiting areas for this workshop are located in the "Koto triangle" (delta) which is an area for concentration of lowland rivers. The Floodgate Control Center, the High Tide Management Center at the Tokyo Port, and Koto Inner Rivers as well as super levee of the Sumida River, they all take roles in protecting the cities from storm surge damage due to typhoons.
"The geographical environment of lowland rivers in Tokyo is quite similar to Bangkok's. However, Tokyo's management methods are further developed than Bangkok's and we have much to learn from them."
The participants from Bangkok were constantly impressed with management by the TMG.
"Opening and closing of floodgates are completely controlled by computers. In Bangkok, many of them are manually operated and we cannot say they are managed well."
Once, a cheer arose when they were cruising Koto Inner Rivers by boat. This was at the Ogibashi Lock which is also called the "mini Panama Canal" as it makes rivers with different water levels possible to pass. Going through the Ogibashi Lock towards the Sumida River is one of the visiting routes for this workshop.
Once they entered the lock, the water levels of channel raised artificially. When the water reaches to the same levels as the Sumida River, the floodgate opened. It was just when the floodgate opened that cheers arose from the participants.
"I did not feel any impact!"
There are similar locks in Bangkok but apparently, boats shake badly as if they are about to turn over due to the impact of water which flows into when the floodgates open. It was a moment that all of them got excited with unexpected cheers.

―The pleasure of various cities of Asia coming together and learning

As commented by the participants that the four-day workshop is too short, time passed quickly and the last day of the workshop finally came. All the TMG staff involved in the workshop felt that Q & A and discussion were more active than expected. Some questions got to the point and made our staff say: "I have never been asked a question like this." However, they were stimulated by the participants who were trying to absorbing knowledge actively. They renewed their awareness of measures and shared pleasure of learning together.
We look forward to further strengthening the network between cities in Asia through opportunities like this and hope that will be a chance to develop a solution to the problems each city faces.