Previous versions of the software had a calculation option called "Use EPANET Compatible Results?" which was used to turn off computational changes Bentley had made to the core engine calculation that would change results compared to the results for an equivalent model run in the US EPA's EPANET software. In the current version of the software, however, the "Use EPANET Compatible Results?" has been replaced by a new "Engine Compatibility" calculation option that offers 4 choices as follows:

1. WaterGEMS CONNECT 2.00.12
2. WaterGEMS CONNECT 2.00.10
3. EPANET 2.00.12
4. EPANET 2.00.10

Previously, the "Use EPANET Compatible Results?" option was functionally the same as having choices 2 and 4 only. When the previous property was set to false, you were using option 2. When the previous property was set to true, you were using option 4. For this release of the software we have extended the engine support to include compatibility modes that include the revised engine convergence algorithms in EPANET 2.00.12, in addition to keeping the old behavior that was based on EPANET 2.00.10.

The intent of each of the compatibility modes is as follows:

1. WaterGEMS CONNECT 2.00.12 - Computation engine based on EPANET 2.00.12 with Bentley's own enhancements and features.
2. WaterGEMS CONNECT 2.00.10- Computation engine based on EPANET 2.00.10 with Bentley's own enhancements and features.
3. EPANET 2.00.12 - Computational engine based on EPANET 2.00.12 including any Bentley enhancements and features that do not change hydraulic results compared to EPANET, for models that are able to be completely represented in EPANET.
4. EPANET 2.00.10 - Computational engine based on EPANET 2.00.12 including any Bentley enhancements and features that do not change hydraulic results compared to EPANET, for models that are able to be completely represented in EPANET.

For those interested in what each engine compatibility mode means in more detail we provide the following compatibility matrix.