SWMM56

Subject:  How to see the effect of the Pump Setting in the RTC Rules of InfoSWMM and H20MAP SWMM Step 1.    Pump Startup and Shutoff Depth Depths to turn the Pump On and turn the Pump Off.  In this example, the pump will be off when the Wet Well Depth is less than 2 feet, the Pump will be off between a Wet Well Depth between 2 and 5.75 feet if the Pump is currently Off and the Pump will be On between a Wet Well Depth between 5.75 and 2 feet. Step 2.    RTC Rule for the Pump Setting when the Wet Well Depth is less than 6.25 feet.  We need to add the AND statement so that the setting is only reset when the Pump is On.   You do not want the pump setting to be reset when the pump should be off. Result 1:  The Pump Speed Ratio tells you the Pump Setting Result 2:  RTC Control Rules in the RPT File if you click on Show Control Actions Result 3:   The depth at the Wet Well and the Flow in the Pump   Result 4:  A mixed graph of the Wet Well Depth and Pump Flow shows the effect of the R

Variable Time Step in SWMM 5 v   The goal of the link lengthening in SWMM 5 it to meet the CFL time step condition for the full link depth and full link velocity at the chosen lengthening time step.  If the link does not meet the CFL condition then this means the time step needed is smaller than your selected lengthening time step.  SWMM 5 will make an hydraulically equivalent longer link with a smaller roughness but the same full flow velocity as the shorter link. v   If you are running a simulation in which all of the pipes are exactly full – no surcharge in any pipe – and the variable time step then there would be no need for SWMM 5 to use anything other than the minimum of the routing or lengthening time step.  However, since most real networks have a mixture of partial flow, surcharged flow and pressure flow, the actual time step depth, velocity/Froude Number is different than the assumed full depth and full flow velocity.  For example, the depth can be higher at one end of the pi