Volume of trapezoidal channel
Volume of trapezoidal channel
(OP)
I'm wondering if anyone has another method of determining the volume of water that is detained in a trapezoidal channel with check dams that measures 2.5'H x 8'BW x 18'TW (2H:1V sides). Check dams are the H (2.5') and are spaced 78' apart. Longitudinal slope of the swale is 0.032ft/ft.
I am just calculating the volume of a trapezoidal pyramid to get the volume of water. (1/3A*h - Where A is the area of trapezoid and h is length of swale) So behind one check dam I can get 845cf of storage before overtopping. It seems right to me. Anyone see a flaw with this?
I am just calculating the volume of a trapezoidal pyramid to get the volume of water. (1/3A*h - Where A is the area of trapezoid and h is length of swale) So behind one check dam I can get 845cf of storage before overtopping. It seems right to me. Anyone see a flaw with this?





RE: Volume of trapezoidal channel
Hope this helps.
RE: Volume of trapezoidal channel
RE: Volume of trapezoidal channel
RE: Volume of trapezoidal channel
V = L[BH/2 + zH^2/3]
Because it tapers to a line, not a point.
Solved by integrating the area B(xS)+z(xS)^2 from length x = 0 to L,
Where the water depth at any location = xS
L = length of channel
B = base width
H = maximum depth of water
z = channel side slope
S = channel longitudinal slope
RE: Volume of trapezoidal channel