This underground in Fukuoka, Japan, was flooded in 1999 by torrential rains.

Source: Making Great Breakthroughs - All about the Sewage Works in Japan (Japan Sewage Works Association: Tokyo, ca. 2002), p. 32.

Stormwater control measures must often be included in the "combined" wastewater and storm water systems found in many parts of Japan.

Source: Making Great Breakthroughs - All about the Sewage Works in Japan (Japan Sewage Works Association: Tokyo, ca. 2002), p. 33.

Diagram showing problems with "combined" sewage systems and improvements in Japan, circa 2002.

Source: Making Great Breakthroughs - All about the Sewage Works in Japan (Japan Sewage Works Association: Tokyo, ca. 2002), p. 34.

High-rate Filtration Facility at the Shibaura Treatment Plant in Tokyo, Japan. This is one of the measures used to improve the "combined" system of wastewater and storm water that many large cities in Japan use.

Source: Making Great Breakthroughs - All about the Sewage Works in Japan (Japan Sewage Works Association: Tokyo, ca. 2002), p. 35.

Trunk stormwater pipe in Japan. The first flush of stormwater is temporarily diverted to reservoir pipes due to a substantial pollution load.

Source: Making Great Breakthroughs - All about the Sewage Works in Japan (Japan Sewage Works Association: Tokyo, ca. 2002), p. 35.

Diagram of a stormwater reservoir used in Japan to improve the "combined" sewer system and control flooding.

Source: Making Great Breakthroughs - All about the Sewage Works in Japan (Japan Sewage Works Association: Tokyo, ca. 2002), p. 35.

Snow melting system using treated wastewater in Japan. In snowy regions, treated wastewater is used in snow-melting ditches and tanks, snow-flowing pipes and other facilities.

Source: Making Great Breakthroughs - All about the Sewage Works in Japan (Japan Sewage Works Association: Tokyo, ca. 2002), p. 37.

The Hanamigawa Dragonfly Pond in Chiba Prefecture, Japan, uses treated wastewater to restore the natural habitat.

Source: Making Great Breakthroughs - All about the Sewage Works in Japan (Japan Sewage Works Association: Tokyo, ca. 2002), p. 37.

Diagram showing the use of optical fiber cables for sewerage system management in Japan. Optical cables are allowed in Japanese sewer pipes after the Sewerage Law was revised in 1996.

Source: Making Great Breakthroughs - All about the Sewage Works in Japan (Japan Sewage Works Association: Tokyo, ca. 2002), p. 38.

The Arakawa Nature Park in Tokyo, Japan, is part of a wastewater treatment plant. It includes baseball fields, tennis courts, and other activities for the local community. With overcrowded cities, Japan has emphasized multiple uses for land in the sewerage treatment system.

Source: Making Great Breakthroughs - All about the Sewage Works in Japan (Japan Sewage Works Association: Tokyo, ca. 2002), p. 39.