How do I run the sewer gems model version 4 in modified rational method (solver) to calculate size of storm water attenuation tanks, for different return durations. As I need to design the tank for critical storm duration.
Hello Anita,
There is not a feature to directly design the size of a wet well or tank in SewerGEMS, but you would be able to model different sizes with different storm events pretty easily. Using scenario management would be best option, since you would be able to directly compare the results. For instance, if you have two scenarios with two different tank sizes, you would be able to graph tank results (like hydraulic grade or percent full) in the same graph to see the impact on the tank size. Similarly, you would be able to compare results for one tank size against multiple storm events.
You also mention critical storms. We have a wiki on running a Critical Storm Analysis. Wet wells are not included in the supported elements to view results. Manholes, catch basins, and outfalls can be used.
Regards,
Scott
To add to this, you can look into using PondMaker as well. Modeling the tank as a pond (like an underground storage chamber) may help with the sizing the stormwater attenuation tank.