Study of Flood Proofing Barriers in Lower Mainland Fish Bearing Streams May 1999 Department of Fisheries and Oceans Habitat and Enhancement Branch Pacific Region Prepared by: Alan R. Thomson and Associates 1124 Hoover Street, Nelson, BC. Tel: 250-352-0016
[email protected] and Confluence Environmental Consulting Whistler, BC. Executive Summary Pumping stations on the lower Fraser River are well known to impart significant mortalities on migrating salmonids, specifically smolts and kelts, that are out migrating from lower Fraser River natal streams to the estuary during the Fraser River freshet. Although several studies have determined that pumping stations kill out-migrating fish, little is known about pumping stations' ability to limit in-migrants from accessing natal and non-natal stream habitat during winter months. In this report, fish migration issues are scoped for ten pumping stations and associated flood boxes on the lower Fraser River from Hope to Richmond. The majority of pumping stations likely constitute a barrier to in-migrating juvenile salmonids, and kill out-migrating fry, smolts and kelts that exit their natal stream after the Fraser River freshet arrives. Each of the ten pumping stations is described, analyzed and discussed with the intent of developing recommendations for operational and capital changes and for further study. Research on the pumping stations / fish migration conflict by water resources and biology professionals from Canada and the United States is also presented. Options to address the conflict are discussed and include changing the type of pump, installing pump bypass systems, changing operational procedures at each facility, conducting fish salvage operations, allowing marginally productive land to flood, and installing higher volume flood boxes with lighter flap gates.