High Head at all the nodes

[Rohini]

When I ran my model in epa swmm, I am getting really high head and depth at all the nodes (nearly 800 ft above the actual water head elevation), Even the profile view is showing water elevation nearly 800 feet above ground elevation. And when I ran the same model in XP SWMM, I am getting acurate results (stage 790 to 900ft).
Free type outfall condition was used in both the softwares, It would be a great help if anyone could look into the model and suggest the changes needed.

Thanks in advance
Rohini

[Debajit Basu Ray]

Hi,

I reviewed the model and the problem is that all the pipes "Inlet Offset" and "Outlet Offset" are actually defined as "Inlet Elevation" and "Outlet Elevation". Please draw the profile plot and you will be able to see the problem.

So, for example Pipe # L17, has "Inlet Offset" and "Outlet Offset" defined as 805.33 ft and 801.190 ft. They should be 0 ft and 0 ft respectively.

Thanks,

Debajit Basu Ray
debajit@bossintl.com

[Rohini]

Thanks a lot for the help, now I am able to fix the problem. Actually I exported the model from XP SWMM which exports pipe inverts as absolute elevation, while SWMM 5 uses relative offsets by default.
And when I changed the offsets to 0 as you said, I am getting correct water surface elevations.

Thanks again.