As part of Learning from Disaster: Miyakejima and New Orleans, we organized a number of meetings for the delegation from New Orleans. Over the next week or so, I will be writing about some of things we learned.
On the first day, we met with the Ward Chief for Sumida Ward and heard about the preventive measures the local government and citizens are taking regarding potential flooding, fires and earthquakes.
Despite the fact that the last major flood in the Sumida Ward of Tokyo took place in 1958, the local government and the Tokyo Metropolitan Government take seriously the possibility of flooding. Two rivers flank Sumida Ward—the Sumida River on the east and the man-made Arakawa River on the west.
The biggest problem is concentrated torrential rains that are contained to small areas. Even if the torrential rain doesn’t take place in Sumida Ward, it is vulnerable because water flows to Sumida Ward via the Sumida River. The result is overflowing sewage drain pipes.
Efforts are underway to separate the sewage system and the rain drainage systems, but to help alleviate the effects of rain, the Ward has developed a rain harvest system to lesson the load on the sewage system.
The water is not potable, but can be used to wash cars and water gardens, for example. There are over 100 facilities to store rainwater large and small. Small efforts include homes in the neighborhood have pipes to collect the rainwater and facets that residents can go to in their neighborhoods to access the water.
Large efforts includes the National Sumo Stadium, which has one of the largest rainwater collection facilities. The rainwater collected here is stored underground and is used to flush the toilets in the stadium.