Channel Parameters (Input Values)

 :1
 :1
ft
ft ⁄ ft
cfs
na

Output

Channel Discharge    Q=1.49⁄n Aw  R h2⁄3 So½
= 1.49⁄0.035 ( 11)(0.768) 2⁄3(0.01)½
= 39.161 cfs

Channel Flow Velocity    V = Q⁄Aw = 39.161⁄11
= 3.56 ft/s

Freeboard    Fb = 1⁄6(d + V2⁄(2(g)))
= 1⁄6(1 + 3.562⁄(2(32.174))) = 0.199 ft

Top Width    TW = LB + RB + W
= 3 + 3 + 8 = 14 ft

Manning Equation Variables

Wetted Area of Flow    
A w=(d)(LB)(½) + (d)(RB)(½) + (W)(d)
= (1)(3)(½) + (1)(3)(½) + (1)(8)
= 11 ft2

Wetted Perimeter    Pw= RBP + LBP + W
= 3.162 ft + 3.162 ft + 8 ft
= 14.325 ft

Hydraulic Radius     Rh=Aw⁄ Pw=11 ft 2 ⁄ 14.325 ft
= 0.768ft

Channel Geometry Variables

Left Bank Width    LB = (d)(Left Bank Slope)
= (1)(3) = 3 ft

Right Bank Width    RB = (d)(Right Bank Slope)
= (1)(3) = 3 ft

Right bank perimeter length
RBP = √( RB2 + d2 ) = √(32+ 12) = 3.162ft

Left bank perimeter length
LBP = √( LB2 + d2 ) = √(32+ 12) = 3.162ft