The left overbank n-value of 0.05 and the right overbank n-value of 0.05 are less than or equal to the channel n-value of 0.05. Follow the procedure in (FHWA, 1984) to compute the n-value for the natural floodplain and the channel. Or follow the procedure in (USGS, 1977) to compute the n-value for urban development. Please submit supporting information on the evaluation of n-values.

LenChl Up/TopWdthAct Dn = 2.14. The ratio is more than 1.1. LenChlUp is more than 500 feet. This cross section is located too far upstream from the critical depth cross section 27878 for the 1%-annual-chance flood. The cross section should move closer to the critical depth section, or an additional cross section should be added between the two cross sections. The HEC-RAS geometry file may need to be recreated using a GIS program.