We created a rain garden at Nanryo High School.

On August 23rd and 24th, we created a rain garden designed by students from Nanryo High School.

In addition to preventing stormwater runoff, this rain garden is the first of its kind to be built by high school students, and its purpose is to convey the significance of storing and infiltrating rainwater, as well as the importance of green watershed flood control.

To date, we have held four workshops with the Prefectural University of Kumamoto, Kyushu University, and Kumamoto University to create rain gardens with Nanryo High School students (June 23, July 7, July 11, July 22). During this process, the high school students learned about green watershed flood control and rainwater infiltration, selected a location for the rain garden, and designed a rain garden that was inspired by the Hitoyoshi Kuma region.

The rain garden is approximately 15m² (3.4m x 4.5m) in area and 0.2m deep. It collects rain that falls on the school building roof (approximately 17m²), stores it, and allows it to infiltrate.

The maximum storage capacity is about 3 tons, and assuming that the water seeps in at about 100 mm per hour, that means about 1.5 tons will seep in per hour. We plan to measure the amount of water seeping in in the future.

Here is a picture of the work. They worked hard despite the heat.

Excavating by hand was very difficult, but we managed to complete it.

We plan to measure the effects of this rain garden together with the high school students.

We also plan to plant more plants and complete the project once the weather cools down in the fall.