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

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therefore, de-watering will be required for the structure and bypass pipe.

Improvements to Protect Endaneered Fish

This Predesign Memorandum examines five fishscreen options and two bypass alternatives.

Options A through D involve the construction of a sedimentation basin and trashrack. The

sedimentation basin is located just downstream from the headworks and contains an access ramp

for equipment access to remove sediment. The trashrack will be manually raked from a deck

extending the length of the trashrack.

Screen Options A through D also place the angle of the screen to the angle of flow at 14 degrees.

Assuming designing all screens for an approach velocity normal to the face of 0.5 fps, the 14

degree angle will result in a sweeping velocity at the screen of2.0 fps.

A gantry crane to facilitate the removal of the screen components was suggested in the design

data. This feature was not included in Options A through D presented in this memorandum. It is

recommended to use a mobile crane to remove screen panels or drums for these options for

maintenance. Access will be provided on both sides of the screen structures with a maximum

crane reach of approximately 40 feet. Removal of screens is anticipated to be a less than an

annual event. However, if desired a gantry crane can be added.

The screen and bypass options are described as follows:

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