SWMM is a free open-source hydrology, hydraulics, and water quality application from the US Environmental Protection Agency that has been developed over the past 30 years. It is primarily used for stormwater management. SWMM5 is the current version: [url removed, login to view] I am on an advisory committee for development of a Low Impact Development Manual. Low Impact Development (LID) is a design approach that attempts to mimic the natural hydrologic cycle at a project site after construction has been completed. Land development generally has very negative affects on the environment and LID offsets that impact. There is one primary limitation to SWMM5 being applied to LID; once stormwater leaves a subcatchment (a watershed node) and goes into a pipe, channel, or other conveyance (a link), the stormwater cannot be infiltrated into the ground. You can approximate water infiltrating into the ground using storage units, orifices/weirs, and pipes to represent the process, but it is not a straightforward or a direct analogy. From my reading of the program code, there is a solution to this which could be afforded fairly quickly by someone relatively proficient with the C/C++ programming and basic Delphi/Pascal: modify SWMM5 to provide the capability for stormwater to go from a link to a subcatchment. This would allow direct simulation of infiltration focused stormwater management measures as well as associated evapotranspiration and irrigation as well. I am donating my time for this (as a bunch of my time is for all sorts of stuff) and I am willing to pay for a coder to work with me on this (it's been over twenty years since I actively programmed much of anything, though I used to code a lot). I can read the code and figure out what needs to be done, but figuring out the syntax would take me a while to work out. I will need to work with with the coder to explain what to do as this is an engineering problem. Amount of work expected to be 12-24hrs.
*** See attachment for information. *** The change/work is not as complicated as it may appear from the "[url removed, login to view]" document (attachment). I know most (or all) the code areas that need changing and can direct the work to those areas. The most important part the coder must provide is getting the program syntax correct. 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, providing the same level of functionality as the original SWMM5 software package and with the extended ability described below. 3) Extended ability is the allowance for stormwater to pass from links to subcatchments in the same manner as stormwater (runoff) from one subcatchment is passed to another subcatchment (as runon). This must be fully facilitated through the GUI. 4) All deliverables will be considered "work made for hire" under U.S. Copyright law. All licenses and copyrights will be as the current version of SWMM5.
Same platforms and requirements as current version of SWMM5. *** See attachment for information.