CN numbers for ufrm model

Software Support
1

What should be CN number of waterBodies? My waterbodies are both the stream and the pond. I assumed the amc3 conditions and assigned 100 for the curve number. but it is showing very high number in runoff.

2

Hi @Rahi -

By definition of curve number, high numbers indicate more runoff. The User Guide includes advice for setting CN for waterbodies, which is consistent with many other sources that recommend setting them to 99 or 100.

In practice, it is up to you to decide whether to give high values to waterbodies (indicating that they are full and subsequent rain will run off), or low values (indicating that perhaps lakes and ponds in particular are not full and would hold most of the water and very little will run off).

~ Stacie

3

thanks. Can you please give your feedback on my damage table confusion post??

4

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