Explicit Solver limitations

Hello,

I am simulating a stormwater network (in sewergems) where I have channels, conduits, manholes, Ponds (3 nos), POS, Pumps. I can not simulate this in Implicit solver (as it takes hours and giving unstable results).

When I simulate in Explicit solver, seems it does not gives accurate results for the conduits. how much I increase the rainfall, the HGL does not exceed the manhole ring level. I just did a trial by increasing the manhole ring level by 1 m and then HGL reaching that ring elevation (or in between elevation. How can I adjust this issue?

BR

Nishadi