EPANET is a program that performs extended period simulation of hydraulic and water quality behavior within water distribution system pipe networks. A network can consist of pipes, nodes (pipe junctions), pumps, valves and storage tanks or reservoirs. EPANET tracks the flow of water in each pipe, the pressure at each node, the height of water in each tank, and the concentration of a chemical species throughout the network during a multi-time period simulation. In addition to chemical species, water age and source tracing can also be simulated.

The EPANET Programmer's Toolkit is a library of functions (or API) written in C that allow programmers to customize the use of EPANET's hydraulic and water quality solution engine to their own applications. Both EPANET and its toolkit were originally developed by the U.S. Environmental Protection Agency (USEPA).

The OWA-EPANET Toolkit is an open-source version of the original EPANET Toolkit that extends its capabilities by:

providing a full set of functions to set and retrieve values for all parameters contained in a network model
allowing networks to be built completely from function calls instead of from an input file
allowing multiple projects to be analyzed in parallel in a thread-safe manner
adding the ability to use pressure dependent demands in hydraulic analyses
producing more robust results with regard to hydraulic convergence, low/zero flow conditions, and water quality mass balance
achieving faster run times for single period hydraulic analyses.

Before using the OWA-EPANET Toolkit one should be familiar with the way that EPANET represents a pipe network, the design and operating information it requires, and the steps it uses to simulate a network's behavior. The following topics provide some introductory material on these subjects:

More detailed information can be obtained from reading the EPANET 2 Users Manual.

Note: OWA (Open Water Analytics) exists on GitHub as an open community for the exchange of information and ideas related to computing in the water & wastewater industries. Its activities and code projects are neither affiliated with nor endorsed by the USEPA.