Water used in Higashihiroshima City comes from Koyo Water Intake Facility in Koyo Cho, Asakita District, Hiroshima City. Koyo Water Intake Facility draws water from the Otagawa River and Gonokawa River. Rain that fell on the Chugoku Mountains flows into these rivers. Water from the Gonokawa River is retained first in the Haji Dam in Yachiyo Cho, Akitakata City, and sent through a tunnel.
　Water from Koyo Water Intake Facility is sent to Senogawa Water Purification Plant in Hiroshima City Aki District, through a tunnel and then to Kumano Cho and Higashihiroshima City through water pipes.