Harrison River Watershed Habitat Status Report
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Harrison River Watershed Habitat Status Report Prepared For: Suzanne Thorpe Fisheries and Oceans Canada May 10, 2010 Prepared By: Monica Pearson, B.Sc., Dipl. Tech., Biologist Lesley-Ann Chiavaroli, B.Sc., Research Assistant BALANCE ECOLOGICAL 1940 Napier St. Vancouver BC Canada V5L 2N5 Tel: (778) 868-8507 ACKNOWLEDGEMENTS Many people were consulted in the development of this document, and gave freely of their knowledge and resources. Matt Foy (DFO) provided boxes of historic information and background knowledge of the watershed, as did Rick Stitt and Wayne Charlie (Weaver Creek Hatchery). Vince Busto, Jeremy Hume, Kimberly Sandve and Angeleen Olsen provided useful documents within DFO, as did Lance Lilley, David Bennett and Wendy Bales from the Fraser Valley Regional District. Thanks to Ken Peters for the lecture on sockeye salmon in the Harrison watershed that provided our first insight into the complexity of the salmonid CUs in the area. Liz Freyman, Jennie Aikman and Rob Knight helped to track down information within the B.C. Ministry of Environment. Many more pointed us towards these knowledgeable people, and helped us identify sources of information along the way. Final thanks to Suzanne Thorpe for guiding the work and providing careful edits to the drafts. i EXECUTIVE SUMMARY Fisheries and Oceans Canada adopted the Wild Salmon Policy (WSP) for the conservation of wild Pacific Salmon in 2005, with the overall goal of restoring and maintaining healthy and diverse salmon populations and their habitats. Strategy 2 of WSP requires the assessment of habitats associated with salmon Conservation Units (CUs). The purpose of this document is to summarize the habitat conditions impacting salmon CUs in the Lower Harrison River Watershed (LHW), to select habitat indicators appropriate to the watershed and conservation units, and to identify existing reports to inform habitat status. The Lower Harrison Watershed is the southernmost and downstream portion of the 8,324 km2 Harrison- Lillooet watershed. Nine salmon Conservation Units are known to occupy 32 named habitats in the watershed, 17 of which are addressed in this document. The geographic scope of this project and preliminary identification of high-value habitat were determined from the Province of British Columbia Integrated Land Management Bureau’s (ILMB) online mapping system iMap. Potential habitat indicators were selected based on the habitat type. Given the geographic scope of the work, and the presence of distinct conservation units in multiple sub-habitats, information was organized geographically. Interviews were conducted with DFO staff, as well as staff from the Regional District, Municipalities, and knowledgeable locals. It was beyond the scope of this project to analyze raw data to inform habitat conditions, but we have identified available raw data that can be compiled into useful habitat status indicators. Land cover data is available for the watershed, albeit out-of-date. Water licenses in the watershed are mostly held by Fisheries and Oceans Canada, however new water licenses have been sought or obtained by independent power producers (IPPs) on several streams in the LHW, which will impact flow patterns in affected streams. LHW tributaries are naturally oligotrophic and although agricultural / urban pollutants are insignificant in much of the watershed, the southern portion is recipient to non-point and point-source pollution. Long-term temperature data is available from six habitats; where compiled, temperature data consistently indicated summer temperatures at levels stressful to fish. Tipella Creek was the only drainage in which known temperature data did not show stressful summer temperatures. Eleven high-value salmon streams in the LHW in the lower portion of the LHW are estimated to have critically low flows below the mean annual discharge benchmark for instantaneous flow for survival of most aquatic life. Those tributaries in the upper portion of the LHW all maintain adequate or good low flow summer habitat. Sakwi Creek is the most vulnerable to discharge instability, due to its denuded headwaters and high extraction allowances. The most severe limiting factors in the Harrison Watershed result from excessive forest harvesting and the related channel instability, road density, riparian removal, and water temperatures increases. Impacts predicted due to climate change will further affect water temperatures and flows, reducing the availability and quality of habitat for alevin, fry and spawners. Nutrient availability in streams is low and may become a limiting factor if not replenished by returning adults. Water extraction from IPPs will impact flow patterns, and should be carefully monitored to ensure impacts to downstream spawners and eggs are minimized. Forest harvest is the most significant land use in the LHW, and information regarding percent of watershed logged is out-date and sometimes conflicting. B.C. Ministry of Forests and Range maintains maps and archives of completed and planned forest harvest, and should be approached to access the data for analysis. By compiling statistics regarding road densities and forest harvest in the LHW, habitat managers would have the ability to infer a wide range of habitat status indicators, including riparian connectivity, water temperatures, and flow stability. ii TABLE OF CONTENTS 1 INTRODUCTION ...........................................................................................................................1 2 METHODS ..................................................................................................................................1 2.1 IDENTIFICATION OF THE GEOGRAPHIC AND BIOLOGICAL SCOPE OF WORK ..............................................3 2.2 IDENTIFICATION OF HABITAT INFORMATION – FART 1 ........................................................................4 2.3 EXTRACTION / ORGANIZATION OF INFORMATION ..............................................................................4 2.4 IDENTIFICATION OF HABITAT INFORMATION – FART 2 ........................................................................4 2.5 INTERVIEWS ................................................................................................................................5 2.6 HABITAT STATUS REPORT DEVELOPMENT ........................................................................................5 2.7 METHODS RECOMMENDATIONS.....................................................................................................6 3 LOWER HARRISON WATERSHED......................................................................................................6 4 SALMONID CONSERVATION UNITS...................................................................................................9 4.1 CHINOOK CONSERVATION UNITS ..................................................................................................11 4.1.1 Lower Fraser Fall White (CH 3) .......................................................................................12 4.1.2 Lower Fraser Spring (CH 4) .............................................................................................13 4.1.3 Lower Fraser Summer Chinook (CH 6) ............................................................................13 4.2 LOWER FRASER RIVER CHUM CONSERVATION UNIT (CM 2) .............................................................14 4.3 LOWER FRASER COHO CONSERVATION UNIT (CO 2)........................................................................15 4.3.1 Coho Creek group ...........................................................................................................17 4.4 LOWER FRASER PINK CONSERVATION UNIT (PK1)...........................................................................17 4.5 SOCKEYE CONSERVATION UNITS ...................................................................................................19 4.5.1 Lake-type Harrison Downstream Lower Fraser (SK L-3-3) ..............................................20 4.5.2 Lake-type Upstream Lower Fraser (SK L-3-4) .................................................................20 4.5.3 River-type Lower Fraser (R03) ........................................................................................22 5 HIGH VALUE HABITATS ...............................................................................................................22 5.1 BIG SILVER CREEK ......................................................................................................................22 5.2 CHEHALIS RIVER ........................................................................................................................24 5.2.1 Chehalis Lake..................................................................................................................30 5.2.2 Coho Creek......................................................................................................................30 5.3 COGBURN CREEK .......................................................................................................................31 5.4 DOUGLAS CREEK........................................................................................................................32 5.5 HARRISON RIVER .......................................................................................................................33 5.5.1 Harrison Lake..................................................................................................................36 5.6 MORRIS CREEK / SLOUGH ...........................................................................................................37