2023 Volume 14 Pages 15-35
Heavy rainfall caused by a baiu-front from July 5 to 8, 2018 and by an autumn rain front from August 11 to 14, 2021 raised the water level of the Chikugo River, resulting in internal flooding in Kurume City, located in the Chikugo region of southern Fukuoka Prefecture. In particular, in the watersheds of the Kanamaru and Ikemachi Rivers, which are tributaries of the Chikugo River, factories, houses, and apartment complexes were flooded and suffered flooding depths of up to 150 cm. The Kanamaru and Ikemachi river basins are flood plains, and in 1900, rice paddies were spread over low-lying areas. However, in the 1960s, a central purification center was constructed, and in the 1980s, an industrial park was opened and houses and apartment complexes were gradually built. The flooding damage in 2018 and 2021 was caused by the Kogasaka Drainage Pump Station on the Kanamaru River, which flows into the Chikugo River, closing the sluice gate due to the rising water level of the Chikugo River caused by heavy rains and the inability to operate drainage pumps due to the rising water level. Currently, efforts are being made by Fukuoka Prefecture and Kurume City to reduce internal flooding.
