How much backwater will the dam cause for a flow of 1000 cfs if the normal depth for this discharge is 5 ft and the dam height is 4.0 ft? (cont.)

How much backwater will the dam cause for a flow of 1000 cfs if the normal depth for this discharge is 5 ft and the dam height is 4.0 ft?

FUNDAMENTALS OF ALLUVIAL CHANNEL FLOW

4_010491
Page Navigation
131

and from Equation 2.144

Hmin = 2 yc = 2 1.46 ft = 2.19 ft

Assuming no energy loss, the specific head upstream of the dam is

H = Hmin + ∆Z = 2.19 + 4.0 = 6.19 ft

To determine the depth of flow upstream of the dam (y) solve the specific head equation (Equation

10 + y = 6.19ft

y3 - 6.19 y2 + 102/64.4 = 0

The solution is

As the normal depth is only 5 ft, the backwater is

∆y = 6.14 - 5.00 = 1.14 ft

That is, the depth upstream of the dam is increased 1.14 ft by the 4.0 ft high dam when the flow is

Western Governors University

Privacy Statement
Press Release
Contact

Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business