High Quality Content by WIKIPEDIA articles! EPANET is a public-domain, water distribution system modeling software package developed by the United States Environmental Protection Agency`s Water Supply and Water Resources Division. It performs extended-period simulation of hydraulic and water-quality behavior within pressurized pipe networks and is designed to be "a research tool that improves our understanding of the movement and fate of drinking-water constituents within distribution systems". EPANET first appeared in 1993.