Which version of the EPA SWMM numerical solver is used by SewerGEMS and CivilStorm, when the active solver is set to "Explicit" in the calculation options?
As new versions of SewerGEMS and CivilStorm are released, they generally use the latest version of the underlying EPA-SWMM technology (the solver) when using the Explicit solver. There are also some Bentley-specific enhancements made to the solver. Starting with the CONNECT Edition Update 2 release of SewerGEMS and CivilStorm, you can run the SWMM engine with the Bentley extensions turned off. The default setting is to use the Bentley enhanced version. To do so, open the calculation options properties and set Solver Compatibility to “SWMM (EPA 5.1.012).” See the section below for details.
The SWMM solver version number used can be found by computing a model while using the Explicit SWMM solver. In V8i, SELECTseries 5 and earlier, a text file will appear with the SWMM version number listed at the top.
Starting with the CONNECT Edition of SewerGEMS and CivilStorm, the solver version can be seen in the SWMM output file, saved when saving the model.
You can also refer to the below chart.
EPA-SWMM Solver Version
SewerGEMS/CivilStorm CONNECT Edition Update 2 (10.02.00.XX)
SewerGEMS/CivilStorm CONNECT Edition Update 1 (10.01.00.70 and 10.01.01.04)
SewerGEMS/CivilStorm CONNECT Edition (10.00.00.45)
SewerGEMS/CivilStorm CONNECT Edition (10.00.00.40)
SewerGEMS/CivilStorm V8i SELECTseries 5 (08.11.05.58 and 08.11.05.113)
SewerGEMS/CivilStorm V8i SELECTseries 4 (08.11.04.54)
SewerGEMS/CivilStorm V8i SELECTseries 3 (08.11.03.84)
SewerGEMS/CivilStorm V8i SELECTseries 2 (08.11.02.XX)
SewerGEMS V8 XM (08.09.26.14 and 08.09.26.17)
CivilStorm V8 XM (08.09.26.14 and 08.09.26.17)
The default EPA-SWMM solver included with SewerGEMS and CivilStorm is a "Bentley Enhanced" version, which means Bentley has added functionality so that it more seamlessly integrates with the SewerGEMS/CivilStorm data model and with other Storm-Sewer Products.
It is important to note that as of the initial CONNECT Edition release of SewerGEMS and CivilStorm, the core SWMM hydraulic solver has not been modified by Bentley - it has simply been "enhanced" to provide more results. So, the basic hydraulic results you see when using the Explicit solver in SewerGEMS and CivilStorm should match EPA-SWMM (for the respective version - see table above)
Note: starting with CONNECT Edition Update 2 version 10.02.00.55, you can now choose between the default "Bentley Enhanced" version of the SWMM solver, or the "standard" version of the SWMM solver, with those enhancements turned off. This can be useful if you need to ensure SWMM solver results for your model are fully compatible with EPA-SWMM itself, for example (by turning off the Bentley enhancements noted below).
These are the specific "Bentley enhancements" :
1. HEC-22 Inlet Calculations 2. Ability to compute complex pond outlet structures 3. Headloss Calculations at structures including HEC-22 and Standard Headloss methods 4. Additional detailed results 5. Integrated LID results 6. Tractive Stress Calculations 7. Hydrogen Sulfide Modelling
If the compatibility mode is set to “EPA (5.1.012)”, these enhancements are turned off:
Troubleshooting unstable SewerGEMS and CivilStorm model results using the Explicit SWMM Solver