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EPANET 2.2.0: An EPA and Water Community Collaboration

Published June 22, 2020EPANET mock up of a water systemEPANET mock up of a water system

Protecting and maintaining drinking water distribution systems is crucial to ensuring high quality drinking water. The purpose of a water distribution system is to deliver water to consumers with appropriate quality, quantity, and pressure, from its source to the point of use. The optimal management of these systems requires data and information, including a digital model of the water system depicting its pipes, valves, pumps, tanks, and other attributes.

EPANET was developed by EPA in the 1990s to better understand water quality transport processes in drinking water distribution systems. Dr. Lewis Rossman, an environmental engineer, created EPANET, a user-friendly software application for modeling the hydraulic and water quality behavior of distribution systems. Since then, EPANET has been used by water utilities engineers, consultants, government officials, and academics in the United States and around the world to help design, manage, and understand water systems. EPANET is also used to model contamination threats and evaluate resilience to security threats or natural disasters. 

The first official release of EPANET 2 was version 2.00.05 on June 1, 2000. Between 2000 and 2008, EPA published six significant updates for EPANET. However, more frequent updates are increasingly needed; as well as efforts to modernize the EPANET code base and add the many improvements the research community had developed and published. EPANET is becoming a more widely used and relied upon modeling software tool nationally and world-wide.  With only a few EPA scientists well versed on detailed functions of EPANET, they are unable single-handedly, to provide timely software updates.

“With EPA’s last official release of EPANET occurring in 2008, it has become increasingly more difficult for EPA to maintain and advance EPANET on a regular basis and meet the needs of the EPANET community,” said Robert Janke, EPA research scientist and EPANET project officer. 

In 2015, the Water Distribution System Analysis (WDSA) Standing Committee voted to initiate an open source software project for the continued development of EPANET. This committee is a part of the Environmental and Water Resources Institute (EWRI) - a technical institute of the ASCE (American Society of Civil Engineers. With the announcement of an open source EPANET initiative, the project indicated that it would be owned and managed by the wider WDSA community without affiliation to any private or public for-profit institution or company. In so doing, software developers from EPA and the water community came together via the community organization and forum, Open Water Analytics (OWA), to form and promote an initiative for an open source EPANET. This is a community-organized initiative to maintain and extend EPANET in the public domain. The EPANET developers’ community at OWA is composed of dedicated volunteers from around the world who have a passion for EPANET.

The recently released EPANET 2.2.0 would not have been possible without the dedicated community of volunteer software developers at OWA. EPA’s release of EPANET 2.2.0 represents a collaboration with the WDSA Standing Committee of the EWRI and the community at OWA. It also represents a new, community-based open source software approach to maintaining and advancing EPANET. EPANET 2.2.0 includes numerous substantial improvements over the former version. These include updates to the hydraulic and water quality engines by providing faster, more accurate, and more robust results compared to its predecessor. Everyone is welcome to participate in the EPANET project. Whether helping others to resolve issues, reporting a new unknown issue, suggesting a new feature that would benefit a workflow, or writing code, EPA value’s and appreciate the time and effort of all contributors. The path for contribution starts with entering an issue at Examine the open issues at this link and the conversation around them, and then get engaged!

EPANET 2.2.0 provides an updated and expanded open source water distribution system modeling tool to meet the vastly important needs of water utilities and the water community.

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US EPA’s EPANET 2.2 ProjectExit