9380

• UCREFRP Catalog Number: 9380
• Author: U.S. Bureau of Reclamation.
• Title: Grand Valley Irrigation Company Fish Screens ‎(Predesign)‎.
• USFW Year: 2000.
• USFW - Doc Type: Boise.
• Copyright Material: NO

K = 3.5 from Sheet 4 in Appendix C
V = Canal approach velocity = 1.8 fps
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(TV) 2
H= 1.32 Ii sinA

Where: H = Head loss through trash rack in inches

T = Trashrack bar thickness, assume 3/8-inch

V = Water velocity = approximately 1.6 fps

D = Spacing of trashrack bars in inches, assume 2-inch spacing

A = Angle of inclination of rack with horizontal, assume 63.4 degrees

Using the above data, the head loss through the trashracks, H, will be 0.11 inches, or
approximately 0.01 feet.

Head losses through a louver type fish screen are estimated using Sheet 4 in Appendix C. This

data is from the report Field and Laboratory Tests to Develop the Design of a Fish Screen

Structure, Delta-Mendota Canal Headworks, Central Valley Project, California. The angle of

the line of louvers with the flow is set at 14 degrees. The louvers are assumed to include flow

straighteners and the individual bars are assumed to be 90 degrees to the flow ( further

information concerning the design of louvers will be discussed later in this memorandum). The

head loss through the louvers is estimated by the following equation:

H=K(;;J

Where: H = Head loss in feet