Infiltration Trench with higher Outflow than Inflows

[bassfshng8]

Hello all...

I have a small drainage area (1.60 acres) sheet flowing into an infiltration trench that is 3' wide by 155' long. I have added exfiltration as discarded and the primary outfall is the top of the trench entered as a custon wier. The water surface elevations for all storm events stay below the top storage elevation.

When I run the program it is error free. BUT...my 10 year storm envent inflow is 0.65 CFS, outflow is 0.68 CFS, discarded 0.01 CFS, and primary 0.66 CFS. Why is the total outflow greater than the inflow?

My water quality storm and 2 year storm the inflow is greater than the outflow. The 100 year storm is equal.

Any ideas?

 

[psmart]

This condition should generally be flagged by a warning message. Please click the message for further details and recommendations. If there is more than one warning, be sure to review all the messages to determine the best course of action.

If you have further questions, you may want to send the project file to HydroCAD support.


Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[bassfshng8]

I am error message free....

I guess my next step is to send the project file over...

 

[psmart]

There will always be something in the message window - not necessarily "errors", but hints and warnings about the calculations.


Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[msquared48]

Have you tried to downsize the size of the trench and see what happens?

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask