SWMM 5 Culvert Data from FHWA, HDS No. 5, Hydraulic Design of Highway Culverts, 1985

Subject:  SWMM 5 Culvert Data from FHWA, HDS No. 5, Hydraulic Design of Highway Culverts, 1985

If you use the culvert option in later versions of SWMM 5 then when the inlet control equation flow is less than the computed St Venant flow then the FHWA equations will be used for the current iteration in the SWMM 5 Dynamic Wave Solution.

Three Hidden Secrets to Speeding up your SWMM 5, H2OMAP SWMM or InfoSWMM Model

Minimum Time Step               Average Time Step        Maximum Time Step

   

Minimum Time Step (sec)             0.984

Average Time Step (sec)              9.071

Maximum Time Step (sec)            30.000

Percent in Steady State (%)          0.000

Average Iterations per Time Step  4.821


Use a maximum time that will lower your average iterations per time step to speed up the simulation,decrease the maximum time step to lower the number of iterations, use equivalent conduit lengthening to increase

 the minimum time step, the model is fastest if the minimum and maximum time steps are not too small or large compared to the average time step.  Adjust the stopping toleranceand the number of iterations if you can to speed up your model

You can also decrease the number of iterations or the stopping tolerance to speed up the model or improve the continuity error of the model.   If you are doing a continuous simulation then you can have a reduced graphical output data set to speed up the simulation

  

If you have a duo or quad core computer another option to speed up the simulations is to use 1, 2, 3 or 4 cores for the simulation

Elevation Interpolation from a Contour in H2OMAP SWMM

Subject:  Elevation Interpolation from a Contour in H2OMAP SWMM

The node invert elevation or the node maximum depth can be interpolated if you use the Elevation Interpolation Tool in H2OMAP SWMM.

Steps

Action

1.   Make a Contour Plot of the Node Invert Elevations.

2.   The Created Contours are now a layer in H2OMAP SWMM.

3.   Recreate the Invert Elevation from the Contour by using the Value Field and Interpolate Field.

4.   You can  also estimate the Maximum Depth of the Node from the Contour and the known Node Invert Elevation.