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

downstream side of the drums.

The piers between the individual drums are assumed to be 30 inches wide. With 15 drums that

are 16 feet long ahd 14 piers that are 30 inches wide, the total length along the screens will be

275 feet. Assuming a sweeping velocity of2.0 fps, the contact time along the face of the screens

will be 138 seconds.

Estimated Cost

The Rotary Screen Costs curve is shown in Appendix E. For a flow of 640 cfs, the curve shows

a unit cost of approximately $4,500.00/cfs in 1999 dollars. This estimate will assume a unit cost

of$5,000.00Icfs to allow for inflation and other factors. For a total design flow of 640 cfs, the

estimated project cost will be approximately $3,200,000.00.

Option D - Louvered Screens

General

This option involves the use of louvers to divert fish down the bypass and out of the canal. The

layout of the concept is very similar to Option A, except that louvers are used instead of

perforated plate screens. This arrangement is shown on Figure 6. The louver system consists of

a series of vertical slats assembled as in a venetian blind. The slats are placed along a diagonal

line across the canal. The structure invert in front of the louvers is at E1.4672.6.The base of the

louvers are set at El. 4673.6, one foot above the invert. This will provide a one foot depth to

allow for silt deposition. The minimum design depth on the louvers is at El. 4679.6, which gives
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