Date of Award:

12-2011

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Civil and Environmental Engineering

Committee Chair(s)

Blake P. Tullis

Committee

Blake P. Tullis

Committee

Steven L. Barfuss

Committee

Phaedra Budy

Abstract

Slip lining culverts represent a low-cost technique that can restore life to decaying culverts. However, slip liners are smoother than typical host culverts; therefore, they generate higher flow velocities and lower flow depths within the culvert, which are fish passage barriers. One way to mitigate these barriers is by installing baffles. Unfortunately baffles can jeopardize the flow capacity of the culvert.

The Utah Water Research Laboratory (UWRL) at Utah State University contracted with the Utah Department of Transportation for $85,000 to test the effectiveness of baffles in improving fish passage through culverts. The goal of this project was to identify swimming limitations for fish passage with regard to slope, flow, and velocity in both a baffled and a smooth-walled high-density polyethylene, HDPE, slip liner. The limitations found from the tests were then used to establish slip-lining guidelines for fish passage culvert rehabilitation. Testing involved evaluating the swimming capabilities of wild brown trout in a 60-ft long, 2-ft diameter, smooth-walled and baffled slip liner. In summary, the baffled culvert supported fish passage up to a 3.5% slope whereas the smooth-walled liner only allowed passage up to a 1% slope. Although baffled culverts improved fish passage, they also decreased the pipe capacity by 74% compared to the smooth-walled liner.

This study suggests that baffled slip lined culverts can aid fish passage and are useful for culvert rehabilitation as long as the culvert can still maintain appropriate flow capacity. Applying this knowledge properly to culvert repairs (limited to a 2-ft diameter slip liner) allows for a more economical solution for fish sensitive areas.

Checksum

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Comments

Publication made available electronically December 21, 2011.

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