The hydraulic capacity of storm sewers shall be determined using Manning's Equation:
V = 1.486 R2/3Sl/2
n
n
V = mean velocity of flow in feet per second
R = the hydraulic radius in feet
S = the slope of the energy grade line in feet per foot
n = roughness coefficient
Roughness coefficient (n) values for storm sewer materials can be found in standard hydraulics texts and references.
(Ord. 1999-05, passed 6-8-99)