CENTRAL PUGET SOUND LOW FLOW SURVEY Prepared for The Washington Department of Fish and Wildlife By John Lombard Steward and Associates and Dave Somers Dave Somers Consulting FINAL REPORT November 30, 2004 Steward and Associates 120 Avenue A, Suite D Snohomish, Washington 98290 Tel (360) 862-1255 Fax (360) 563-0393 www.stewardandassociates.com Table of Contents Introduction............................................................................................................................. 1 Definition of Low Flow Problem ........................................................................................... 2 Adopted Regulatory Instream Flows .................................................................................... 6 Climate Change....................................................................................................................... 7 Quantification of Instream Flow Needs ................................................................................ 7 Recommendations.................................................................................................................10 Summary Reports by WRIA................................................................................................ 12 STILLAGUAMISH (WRIA 5)........................................................................................... 12 Environmental Setting .................................................................................................... 12 Draft Stillaguamish – WRIA 5 Chinook Salmon Recovery Plan ................................... 13 Regulatory Setting .......................................................................................................... 14 List of Flow Problems for Fish ....................................................................................... 14 SNOHOMISH (WRIA 7) ................................................................................................... 17 Environmental Setting .................................................................................................... 17 Draft Snohomish River Basin Salmon Conservation Plan ............................................. 18 Regulatory Setting .......................................................................................................... 18 List of Flow Problems for Fish ....................................................................................... 19 CEDAR-SAMMAMISH (WRIA 8) ................................................................................... 23 Environmental Setting .................................................................................................... 23 Priority Areas in Draft WRIA Plan................................................................................. 23 Regulatory Setting .......................................................................................................... 24 List of Flow Problems for Fish ....................................................................................... 24 GREEN/DUWAMISH (WRIA 9) ...................................................................................... 27 Environmental Setting .................................................................................................... 27 Technical Guidance for Salmon Recovery ..................................................................... 27 Regulatory Setting .......................................................................................................... 28 List of Low Flow Problems for Fish............................................................................... 29 PUYALLUP-WHITE (WRIA 10)...................................................................................... 31 Environmental Setting .................................................................................................... 31 Salmon Habitat Protection and Restoration Strategy...................................................... 32 Regulatory Setting .......................................................................................................... 32 List of Low Flow Problems for Fish............................................................................... 33 CHAMBERS/CLOVER CREEK (WRIA 12).................................................................... 36 Environmental Setting .................................................................................................... 36 Salmon Habitat Protection and Restoration Strategy...................................................... 36 Regulatory Setting .......................................................................................................... 36 List of Low Flow Problems for Fish............................................................................... 36 References.............................................................................................................................. 39 Appendices: Data Sheets for Listed Streams...................................................................... 45 Introduction Washington State Water Resource Inventory Areas 5, 7, 8, 9, 10 and 12 (in Skagit, Snohomish, King and Pierce counties), make up the Central Puget Sound region, as defined for this report. This is the most densely populated area of Washington State and one of the most rapidly growing areas in the country. It is home to 5 species of Pacific salmon as well as steelhead, cutthroat, and dolly varden/bull trout and includes thousands of miles of salmon and steelhead habitat. As human population increases, residential, municipal, and industrial demands for water increase. Water for out of stream uses has historically come from either direct withdrawal of surface water from streams, rivers, or lakes, or from groundwater. Not uncommonly, these withdrawals have diminished the quantity and quality of stream habitat, or exacerbated natural low flow problems. As the human population increases, the potential for further degradation and conflicts between instream and out-of-stream needs will also increase. The purpose of this report is to: • Summarize existing information regarding problems for salmonids caused by human- reduced stream flows in the Central Puget Sound region; • Identify specific streams and stream segments that have been identified as having low flow related habitat limitations; • Identify the suspected causes of these low flow problems and their likely effects on salmonids; and • Discuss some potential next steps for evaluating the significance of these problems and actions that could be taken to address them. The information in this report has been gleaned from numerous ecological assessments and reports generated over the past several decades for the watersheds of the Central Puget Sound Region. Most of these assessments have been broadly focused on salmonid habitat conditions and impacts, and have not focused on water quantity and instream flow issues. As a result, the information regarding the extent and nature of stream flow issues is in most cases general in nature. This information has been supplemented with further detail from interviews with natural resource professionals in the region. We hope that this report can serve as a basis for developing strategies to address regional stream flow issues. This report does not attempt to provide detailed background information about general environmental conditions within a watershed, or other factors influencing anadromous fish habitat. Each basin in the study area has been the subject of extensive prior assessment and documentation such as recent Limiting Factor Analyses (LFA’s) conducted by the Washington State Conservation Commission, and various WRIA assessments conducted for a variety of purposes including Endangered Species Act planning, water resources planning, water resource characterization, and environmental assessment. Where appropriate, this report summarizes key information from these studies, but readers interested in more detailed information on environmental conditions within each watershed are encouraged to consult the references listed. In addition, readers are specifically referred to the Washington State Department of Fish and Wildlife (WDFW) website, Salmonscape, at http://wdfw.wa.gov/mapping/salmonscape. This site provides for interactive mapping of 1 current information on salmonid stock distribution and status as well as a variety of habitat parameters by WRIA, county, or user-defined boundaries. Definition of Low Flow Problem For the purposes of this report, we use the following definitions of “stream flow” and “instream flow”: Seasonal fluctuations are common, often with more water, higher levels and faster flows in the winter or spring months, and less water, lower levels and slower flows in the summer and fall months. Flows also vary from place to place along the stream: at narrow points of the channel the water may be fast moving, whereas at a wide point in the stream the same amount of water may move quite slowly. In this document, the amount of water found in a stream at any given time is referred to as “stream flow.” The term “instream flow” is used to identify a specific stream flow (typically measured in cubic feet per second, or cfs) at a specific location for a defined time, typically following seasonal variations. An instream flow is a state water right; it has a priority date and must be satisfied before junior rights can legally be exercised. Instream flows are usually based on estimates of the stream flow needed to protect