work underway on a water-discharge structure we designed for poor soil conditions
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fish passage evaluation for watershed district

fish passage evaluation for watershed district
client
Ramsey Washington Metro Watershed District
location
Minnesota

options identified to hinder carp movement

The watershed district wanted to curb access of common carp to Kohlman Lake from the upstream waters of Kohlman Basin, Markham Pond, and Casey Lake, which were viewed as likely spawning and nursery areas for the carp.

To identify the routes of passage and possible locations to interrupt carp movements or install fish barriers, Barr evaluated existing structures between Kohlman Lake and Casey Lake at normal water elevations and for the two- and 100-year flood events. Common carp swim and burst speeds were compared with structure hydraulics to determine potentials for passage. We recommended and provided cost estimates for several alternatives to impede carp movement, including traps, physical barriers, and an electric barrier.

An experimental bubble barrier was later installed by University of Minnesota researchers at a location identified by Barr. We designed the structural and electrical elements of the barrier, assisted with installation, and provided construction oversight.