Released June 16, 2017.

This is the source code for OpenSWMM version 5.1.912, a public domain computational engine based on EPA SWMM5 version 5.1.012. It should produce identical results to EPA SWMM5.1.012, provided none of the unique features of this engine are used (see Disclaimer below).

The purpose of the OpenSWMM engine is to:

• provide a method for adding community-generated improvements to the SWMM feature set,
• provide quality control and testing for community-generated SWMM code,
• provide an easier method for the US EPA to incorporate community-requested features into the official version of EPA SWMM, should they so choose, and
• provide a transparent, commentable source code repository to facilitate community education and engagement.

Browse the OpenSWMM website for a more engineer/layperson-friendly code viewer, the visual code explorer and code comparison tools.

For both a summary and a detailed list of changes, please see the OpenSWMM5.1.912 home page on OpenSWMM.org.

When not using the new seasonal modeling capabilities, this OpenSWMM5.1.912 engine should produce output and report files identical to EPA SWMM5.1.012, warts and all. As such, this OpenSWMM engine is provided "as is", without warranty of any kind, and should not be construed as an endorsement or validation of the output of either version. The source code for this engine is provided here and in a more user-friendly form on OpenSWMM.org - it is up to the user to satisfy him/herself that the code changes are correct for their needs and the output is useful. Neither CHI nor the individual authors involved accept liability for any direct or indirect loss arising out of its use.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

This is free and unencumbered software released into the public domain. Anyone is free to copy, modify, publish, use, compile, sell, or distribute this software, either in source code form or as a compiled binary, for any purpose, commercial or non-commercial, and by any means.

In jurisdictions that recognize copyright laws, the authors of this software dedicate any and all copyright interest in the software to the public domain. We make this dedication for the benefit of the public at large and to the detriment of our heirs and successors. We intend this dedication to be an overt act of relinquishment in perpetuity of all present and future rights to this software under copyright law.