ACKNOWLEGEMENTS This capstone project was made possible by the help and resources from the following individuals and organizations. Their invaluable assistance throughout the past year has provided data, background information, regional history, water rights and policy, photographs, and personal support. Tualatin River Watershed Council Steve Trask, Bio-Surveys, LLC Tualatin Riverkeepers Rob Foster, City of Forest Grove Clean Water Services The following OSU instructors have provided support, guidance, and insight throughout completion of the Master of Natural Resources program and this capstone project. Penelope Diebel Ken Diebel Dana Warren Badege Bishaw Lynette de Silva Further, I would like to acknowledge mentor Gary Miniszewski and my parents, who promoted broader thinking, aided work sessions, conducted periodic editorial draft reviews, and provided continued support throughout my capstone project and completion of my Master of Natural resources degree from Oregon State University TABLE OF CONTENTS Pages 1. INTRODUCTION 1 2. LITERATURE REVIEW 4 2.1 Literature Review of Water Flow and Temperature Impacts 4 2.1.1 How to Mitigate High Water Temperature 5 2.2 Literature Review of Economic Analysis 6 2.2.1 Ecosystem Services 7 2.2.2 Cost-Benefit Analysis. 9 3. STUDY AREA 13 3.1 Regional Context 13 3.1.1 Watershed Description 14 3.2 Steelhead Trout 17 3.3 Tualatin River Watershed Council Fish Survey History 20 3.4 City of Forest Grove Water 21 4. FLOW AND FISHERIES DATA 24 4.1 Water Flow of Gales Creek 24 4.2 Fish Surveys 27 4.3 Intake Changes in 2014 32 4.4 Clear Creek Intake versus JWC Intake 33 5. ECONOMIC DATA 36 5.1 Cost Analysis 36 5.2 Funding 37 6. DISCUSSION OF OPTIONS 41 6.1 Proposed Improvement Plan 41 6.1.1 Altering Intake Level 42 6.1.2 Large Woody Debris Restoration 43 7. CONCLUSION AND FUTURE IMPLICATIONS 46 LITERATURE CITED 49 APPENDICES 55 LIST OF TABLES Table 1: Gales Creek Summer Water Flow 2006-2015 26 Table 2: Gales Creek Summer Temperature 2006-2015 26 Table 3: Juvenile Steelhead Numbers & Density Observed from RBA Surveys 2013-2014 29 Table 4: Juvenile Steelhead Number Expansion from 20% RBA Survey Results 30 Table 5: Water Received from JWC 35 Table 6: Forest Grove Water Budget 37 Table 7: 3/4th in. Water Meter Size Revenue 39 Table 8: 2 in. Water Meter Size Revenue 39 Table 9: 30% Reduction of Current Summer Municipal Intake 42 Table 10: Two Week Shutdown 43 Table 11: Expanded Juvenile Steelhead Number for Clear Creek LWD Project 44 LIST OF FIGURES Figure 1: Capstone Project Overview 3 Figure 2: Water Availability and Demand by Seasons 13 Figure 3: Gales Creek Watershed & Tributaries 14 Figure 4: Land Ownership 16 Figure 5: Critical Habitat in the Tualatin River Basin: Gales Creek 19 Figure 6: Population Growth in Washington County 23 Figure 7: 2014 Gales Creek Mean Daily Flow (a proxy to Clear Creek) 25 Figure 8: 2014 Gales Creek Mean Daily Temperature (a proxy to Clear Creek) 25 Figure 9: Steelhead trout Escapement Count at Willamette Falls 28 Figure 10: Steelhead Numbers & Density in the Tualatin River Basin 32 Figure 11: Juvenile Steelhead per pool in Gales Creek (a proxy to Clear Creek) 32 Figure 12: JWC Beginning and Ending Allocation 35 ABBREVIATIONS cfs Cubic Feet Per Second DEQ Oregon Department of Environmental Quality ESA Endangered Species Act FPA Forest Practices Act JWC Joint Water Commission MAD Mean Annual Discharge ODF Oregon Department of Forestry ODFW Oregon Department of Fish and Wildlife OWRD Oregon Water Resources Department PNW Pacific Northwest RM River Mile STHD Steelhead Trout SQM Square-mile TRWC Tualatin River Watershed Council USGS U.S. Geological Survey WTP Willingness-To-Pay 1 Municipal Water Impacts on Steelhead Trout in the Gales Creek Watershed 1. Introduction The Tualatin River Basin is a large watershed in the Upper Willamette Basin of Oregon stretching from the Coast Range to the Willamette River. The Tualatin River is 80 miles long with four major urban tributaries and six major rural tributaries. The Gales Creek Watershed branches from the upper Tualatin River and provides important habitat for salmonid juveniles to rear. Gales Creek’s water quality and habitat for salmonids is vital to the sustainability of the Tualatin River Basin’s native steelhead trout population. The Gales Creek Watershed has a tributary, Clear Creek, that provides municipal water to the city of Forest Grove. Forest Grove is located in Washington County, Oregon. The city of Forest Grove and the rest of Washington County is currently experiencing population growth. Washington County is the third fastest growing county in Oregon, with over an estimated 10,000-person increase in 2015 (Population Research Center 2015). Forest Grove is currently the fastest growing city in Washington County, with a nine percent increase in 2015 (U.S. Census Bureau 2015). The city’s water demands need to accommodate population growth; however, Clear Creek provides water for native fish as well as the city. This population increase has caused many cities in Washington County to reevaluate their water sources for long-term planning. In June of 2015 the Tualatin River Watershed Council (TRWC) gave a public presentation on two years of fish sample survey data of the Tualatin River’s tributaries. The presentation 2 addressed a change in fish numbers and density between 2013 and 2014 in the Gales Creek Watershed possibly due to the in Clear Creek water intake shutdown for two weeks in the summer of 2014 (Trask 2015). This data indicates the need for research as to how municipal water intake may impact fish numbers and density. The fish surveys for the TRWC project collected data on Coho salmon, Chinook salmon, cutthroat trout and steelhead trout. This capstone will focus on the changes and impact on steelhead trout in Clear Creek of the Gales Creek Watershed. There are many variables that impact stream temperature, and decades of human development have altered natural temperature regimes in the Tualatin river network. Managing water diversions is considered a critical action for salmonid recovery throughout Oregon. Common management suggestions to enhance stream habitat include vegetation improvements and instream allocation changes (Meross 2000; Cerda 1991). The objective of this Masters of Natural Resources Capstone project is to examine how municipal water use of the Clear Creek tributary changes habitat requirements for steelhead trout, and to determine if changes of urban water use can increase access to salmonid habitat. Fundamental to this strategy are answers to the following questions: Is the goal to increase fish numbers or access the current habitat? Given limited resources, can water flow levels be increased for the fish while still economically meeting municipal water needs for the city? 3 Capstone Project Overview Figure 1: 4 2. Literature Review This section summarizes the relevant literature on water flow and temperature impacts on salmonids. It also identifies the theoretical basis for my economic analysis of alternative water management. 2.1 Literature Review of Water Flow and Temperature Impacts Stream temperature is a predominant impact on aquatic organisms, and temperature is a control of salmonid growth (Wade et al. 2013). The salmon life cycle is adapted to specific water temperature patterns in their native streams. Fish are exothermic and their life cycle is controlled by temperature (Groom et al. 2011). Low water flow, high air temperatures, and minimal canopy coverage elevate summer stream temperatures in forestlands (Neumann et al. 2006; Groom et al. 2011). Wade et al. (2013) model data has found that rivers west of the Cascades, like the Tualatin River Basin, has the greatest magnitude of low flow. Studies have found that when stream flow is reduced by 90% there is a reduction in invertebrate density, but not when the stream flow is only reduced by 50% (Bradford and Heinonen 2008). It has also been determined that low stream flows decrease riffles and pool habitats, which are preferred by certain salmonid species like steelhead trout (Bradford and Heinonen 2008). Streams used by salmonids for spawning need to maintain a healthy temperature range since salmonid life cycles are effected by water temperature. The “Salmon Restoration in an Urban Watershed: Johnson Creek, Oregon” compiled by Sharon Meross (2000) is a comprehensive overview of the conditions and challenges for salmon in Johnson Creek. Johnson Creek, also part of the Upper Willamette Basin, is 15 miles east of the 5 Tualatin River and has similar habitat challenges as the Tualatin River Basin. The Oregon Department of Environment Quality (DEQ) have a temperature limit of 17.7˚C regulated by Total Maximum Daily Load (TMDL) levels and human use allowances (Meross 2000; DEQ 2012). Stream temperatures above 23˚C can be deadly to salmon because they require specific water temperature levels in order to prevent disease and to stay alive. Steelhead trout have a lower temperature threshold of 18˚C (Thompson 2005). High water temperatures can also decrease dissolved oxygen levels in water. Dissolved oxygen is essential to fish survival (British Columbia Ministry of Environment, Land and Parks 1998). Lastly, studies have found that low water flow habitats can favor exotic species over native species and lower the native success rates (Bradford and Heinonen 2008). 2.1.1 How to Mitigate High Water Temperature It is difficult to cool already elevated water temperatures, but there are many ways to prevent high water temperatures (Thompson 2005). Water flow and shade from streamside vegetation are two variables that impact stream temperature and can be used to mitigate elevated water temperature (Bradford and Heinonen 2008). A study by Groom et al. (2011) researched how stream temperatures respond to timber harvest. Stream temperatures in private forest sites increase on average 0.7° C in response to riparian timber harvest.