EPASWMM
EPASWMM
(OP)
I've been given an assignment to model 2- and 100-year storms for a 70-acre site using EPASWMM. Previously, the local jurisdiction wasn't particular about what software was used on a project, but for some reason they are requiring SWMMM for this one. We have the appropriate IDF curves and coefficients needed to model runoff for those storms, except that EPASWMM doesn't use that data, and the users manual, etc., give no information on how to translate the IDF based data into something that can be input into the EPASWMM model. Can someone explain or point me toward a source that will describe how to develop storm runoff data using IDF coefficients, that can be input into the EPASWMM5.1 model?





RE: EPASWMM
1. use SWMM hydrology to general hydrograph (It is basically a non linear reservoir routing method);
2. develop hydrograph outside of SWMM and introduce them at nodes as external flows;
Also, you need to understand that SWMM is a dynamic model which is different from rational method (a single peak flow), although there are some methods to convert rational method peak flow to a hydrograph - talk to you local agency get their approval first.
RE: EPASWMM
Peter Smart
HydroCAD Software
www.hydrocad.net
RE: EPASWMM
RE: EPASWMM
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: EPASWMM
http://www.hydrocalc.com/beta/rain_ddf/main.html
If NOAA (http://hdsc.nws.noaa.gov/hdsc/pfds/) has the depth duration data for your area, you can follow this hyetograph generator. It basically allows converting depth duration data to IDF coefficients--and then the IDF coefficients to rainfall hyetograph using alternating block method (Chow, Applied Hydrology).
If you need help, pls email me. Thanks
-bs
RE: EPASWMM