Kumamoto has a perennial problem with sediment buildup in its rivers due to both volcanic and farming effluent. One will often notice the color of Shirakawa, whose riverbed is at the same height as its surrounding area and only held in place by its artificial banks, turn coffee-brown during rice planting season, and its coarse black sand ejection from Aso. Removing the sediment before the onset of rainy season is a race against time. Kumanichi reports on the haste. - William https://kumanichi.com/articles/232598