Hey everyone,
My design team and I have been modeling a combination catch basin in Hydraflow Express when we noticed that the precision for the Manning's Roughness Coefficient was locked in the hundredths place (n= 0.01). It would visually show the zero in the thousandths place, but it would round up or down to the hundredths place. After playing around with it we found this rounding was substantial as it would swing the spread by about 3' going from n=0.01 to n=0.02. When, per local standards, we can have n around 0.013-0.015 for a troweled concrete gutter. Has anyone else run into this and if so have you found a way to be able to use more precise roughness values? Thank you!
Ian
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