Resource_Mangement_Plan-HenryHagg2004.pdf

Henry Hagg Lake

Resource Management Plan

U.S. Department of the Interior Bureau of Reclamation Pacific Northwest Region Lower Columbia Area Office

May 2004

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HENRY HAGG LAKE

Resource Management Plan

U.S. Department of the Interior Bureau of Reclamation

Approved:

This Resource Management Plan was prepared by EDAW and JPA under contract for the Department of the Interior, Bureau of Reclamation, Pacific Northwest Region.

Point of Contact:

Karen Blakney U.S. Bureau of Reclamation Lower Columbia Area Office 825 NE Multnomah Street, Suite 110 Portland, OR 97232-2135

(503) 872-2796

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May 2004 T A B L E O F C O N T E N T S 1i1

H E N R Y H A G G L A K E R E S O U R C E M A N A G E M E N T P L A N

Table of Contents

CONTENTS

Chapter 1 Introduction .............................................................................................................. 1-1

1.1 RMP Program and Policy................................................................................ 1-1

1.2 Purpose and Scope of the Plan ........................................................................ 1-1

1.3 Relationship to Tualatin Valley Water Supply Feasibility Study ................... 1-2

1.4 Location and Description of the RMP Study Area.......................................... 1-3

1.5 Project Summary ............................................................................................. 1-4

1.6 Overview of Public Involvement, Agency, and Tribal Coordination ............. 1-7

Chapter 2 Existing Conditions .................................................................................................. 2-1

2.1 Natural Resources............................................................................................ 2-1

2.1.1 Climate ................................................................................................ 2-1

2.1.2 Topography ......................................................................................... 2-1

2.1.3 Geology ............................................................................................... 2-2

2.1.4 Soils ..................................................................................................... 2-2

2.1.5 Hydrology and Water Quality ............................................................. 2-9

2.1.6 Vegetation ......................................................................................... 2-15

2.1.7 Fish and Wildlife ............................................................................... 2-23

2.1.8 Threatened, Endangered, and Sensitive (TES) Species .................... 2-30

2.2 Visual Resources ........................................................................................... 2-36

2.3 Noise.............................................................................................................. 2-38

2.4 Cultural Resources ........................................................................................ 2-39

2.4.1 Historical Overview .......................................................................... 2-39

2.4.2 Archeological Investigations ............................................................. 2-40

2.4.3 Traditional Cultural Properties (TCPs) ............................................. 2-42

2.5 Indian Sacred Sites ........................................................................................ 2-43

2.6 Indian Trust Assets ........................................................................................ 2-43

2.7 Socioeconomics............................................................................................. 2-44

2.7.1 Demographic Profile ......................................................................... 2-44

2.7.2 Economic Setting .............................................................................. 2-44

2.7.3 Park Funding ..................................................................................... 2-45

1ii1 T A B L E O F C O N T E N T S May 2004

CONTENTS

Chapter 3 Existing Land Use and Management........................................................................ 3-1

3.1 Land Status and Management ......................................................................... 3-1

3.1.1 Project Facilities and General Operations ........................................... 3-1

3.1.2 Reservoir Operations........................................................................... 3-1

3.1.3 Land Status and Management ............................................................. 3-2

3.1.4 Contractual Agreements ...................................................................... 3-5

3.1.5 Easements ............................................................................................ 3-6

3.1.6 Encroachments on Reclamation Lands ............................................... 3-6

3.1.7 Adjacent Land Use Patterns ................................................................ 3-7

3.2 Public Services and Utilities............................................................................ 3-8

3.2.1 Electrical.............................................................................................. 3-8

3.2.2 Potable and Non-Potable Water .......................................................... 3-8

3.2.3 Wastewater .......................................................................................... 3-9

3.2.4 Solid Waste.......................................................................................... 3-9

3.2.5 Fire Protection and Emergency Services........................................... 3-10

3.2.6 Law Enforcement .............................................................................. 3-11

3.3 Recreation...................................................................................................... 3-12

3.3.1 Recreation Facilities .......................................................................... 3-12

3.3.2 Recreation Activities and Use Levels ............................................... 3-18

3.3.3 Park Security and Safety ................................................................... 3-22

3.3.4 Special Events ................................................................................... 3-23

3.4 Transportation and Access ............................................................................ 3-24

3.4.1 Major Arterials .................................................................................. 3-24

3.4.2 Local Roads....................................................................................... 3-25

3.4.3 Parking............................................................................................... 3-25

3.4.4 Trails .................................................................................................. 3-25

3.4.5 Reservoir/Boat Access ...................................................................... 3-26

3.4.6 Accessibility ...................................................................................... 3-27

Chapter 4 The RMP Planning Process...................................................................................... 4-1

4.1 Overview ......................................................................................................... 4-1

4.2 Public Involvement Program........................................................................... 4-3

4.2.1 Newsbriefs ........................................................................................... 4-3

4.2.2 Public Meetings................................................................................... 4-3

4.2.3 Ad Hoc Work Group ........................................................................... 4-3

4.2.4 World Wide Web................................................................................. 4-5

4.3 Tribal Consultation.......................................................................................... 4-5

4.3.1 Overview of Government-to-Government Consultation with

Tribes................................................................................................... 4-5

4.3.2 National Historic Preservation Act Requirements .............................. 4-5

4.3.3 Indian Trust Assets .............................................................................. 4-5

4.3.4 Sacred Sites ......................................................................................... 4-6

4.3.5 Other Laws and Regulations ............................................................... 4-6

4.4 Agency Coordination ...................................................................................... 4-6

May 2004 T A B L E O F C O N T E N T S 1iii1

CONTENTS

Chapter 5 Resource Management ............................................................................................. 5-1

5.1 Introduction ..................................................................................................... 5-1

5.2 Goals, Objectives, and Management Actions ................................................. 5-1

5.2.1 Natural Resources (NAT).................................................................... 5-1

5.2.2 Cultural Resources (CUL)................................................................... 5-9

5.2.3 Indian Sacred Sites (ISS)................................................................... 5-11

5.2.4 Indian Trust Assets (ITA).................................................................. 5-11

5.2.5 Recreation and Access (REC) ........................................................... 5-11

5.2.6 Land Use, Management, and Implementation (LMI)........................ 5-18

Chapter 6 Implementation Program.......................................................................................... 6-1

6.1 Introduction ..................................................................................................... 6-1

6.2 Implementation Components .......................................................................... 6-1

6.2.1 Management Actions........................................................................... 6-1

6.2.2 Prioritization........................................................................................ 6-1

6.2.3 Related Management Actions ............................................................. 6-1

6.2.4 Timing and Sequencing....................................................................... 6-2

6.2.5 Lead Agency........................................................................................ 6-2

6.2.6 Funding................................................................................................ 6-2

6.2.7 Monitoring........................................................................................... 6-2

6.3 Amending and Updating the RMP .................................................................. 6-2

6.3.1 Amending Information in the RMP..................................................... 6-2

6.3.2 Updating the RMP............................................................................... 6-2

Chapter 7 Glossary of Terms .................................................................................................... 7-1

Chapter 8 Bibliography............................................................................................................. 8-1

8.1 Literature Cited................................................................................................ 8-1

8.2 Personal Communications ............................................................................... 8-3

8.3 Internet Sources............................................................................................... 8-4

APPENDICES

Appendix A Agency and Tribal Consultation/Coordination Appendix B Legal Mandates Appendix C Problem Statement for the RMP Appendix D Elk Mitigation Meadows Maintenance and Monitoring Plan

1iv1 T A B L E O F C O N T E N T S May 2004

List of Tables Table 2.1-1 Soil types adjacent to Henry Hagg Lake................................................................. 2-7

Table 2.1-2 Pre-reservoir estimated sediment yield and capacity reduction.............................. 2-8

Table 2.1-3 Scoggins, Tanner, and Sain Creek monthly flow data (2000) .............................. 2-10

Table 2.1-4 Beneficial uses identified by ODEQ as occurring in the Tualatin River sub-basin ...................................................................................................................... 2-14

Table 2.1-5 Approximate range of Henry Hagg Lake water quality criteria based upon

2000 collection data .............................................................................................. 2-15

Table 2.1-6 Area of vegetation associations on Reclamation lands at Henry Hagg Lake ....... 2-16

Table 2.1-7 Fish species common to Henry Hagg Lake .......................................................... 2-25

Table 2.1-8 Common reptile and amphibian species occurring in the vicinity of Henry

Hagg Lake............................................................................................................. 2-26

Table 2.1-9 Common bird species occurring in the vicinity of Henry Hagg Lake .................. 2-26

Table 2.1-10 Common mammal species occurring in the vicinity of Henry Hagg Lake........... 2-27

Table 2.1-11 Rare and sensitive wildlife species potentially occurring in the vicinity of

Henry Hagg Lake.................................................................................................. 2-28

Table 2.1-12 TES plant and wildlife species potentially occurring in the vicinity of Henry

Hagg Lake............................................................................................................. 2-31

Table 2.3-1 Estimated noise levels (dBA) from park sources (1994) ...................................... 2-39

Table 2.3-2 Decibel levels of particular noises for comparison purposes................................ 2-39

Table 2.7-1 Washington County and Oregon State population and age distribution............... 2-44

Table 3.1-1 Project specifications .............................................................................................. 3-2

Table 3.3-1 Overview of existing recreation facilities at Henry Hagg Lake ........................... 3-14

Table 3.3-2 Annual attendance at Henry Hagg Lake ............................................................... 3-20

Table 3.3-3 Location of primary residence of visitors to Henry Hagg Lake ........................... 3-20

Table 3.3-4 Activities participated in at Henry Hagg Lake ..................................................... 3-21

Table 3.3-5 Visitors’ favorite locations at Henry Hagg Lake .................................................. 3-22

Table 3.3-6 Desired changes at Henry Hagg Lake................................................................... 3-22

Table 3.3-7 Desired new facilities at Henry Hagg Lake .......................................................... 3-22

Table 4.1-1 Primary issues of concern identified during the initial RMP phase, based on public input ............................................................................................................. 4-2

Table 4.2-1 Ad Hoc Work Group............................................................................................... 4-4

Table 5.2-1 Proposed recreation and access related activities at Henry Hagg Lake................ 5-13

Table 6.1-1 Management Actions for Natural Resources (NAT). ............................................. 6-3

Table 6.1-2 Management Actions for Cultural Resources (CUL) ............................................. 6-8

Table 6.1-3 Management Actions for Indian Sacred Sites (ISS) ............................................... 6-9

Table 6.1-4 Management Actions for Indian Trust Assets (ITAs)............................................. 6-9

Table 6.1-5 Management Actions for Recreation and Access (REC)...................................... 6-10

Table 6.1-6 Management Actions for Land Use, Management, Implementation (LMI)......... 6-15

May 2004 T A B L E O F C O N T E N T S

List of Figures Figure 1.4-1 RMP study area ..................................................................................................... 1-5

Figure 2.1-1 Slope and hydrography.......................................................................................... 2-3

Figure 2.1-2 Soils ....................................................................................................................... 2-5

Figure 2.1-3 Landslides............................................................................................................ 2-11

Figure 2.1-4 Vegetation associations ....................................................................................... 2-17

Figure 2.1-5 Elk meadows ....................................................................................................... 2-21

Figure 3.1-1 Land status............................................................................................................. 3-3

Figure 3.3-1 Existing recreation sites and facilities ................................................................. 3-15

Figure 4.1-1 RMP planning process and RMP schedule ........................................................... 4-1

Figure 5.2-1 Resource Management Plan 2004 ......................................................................... 5-3

List of Photos Photo 1-1 Aerial view of Scoggins Dam, Henry Hagg Lake, and surrounding area............... 1-4

Photo 1-2 Scoggins Dam and spillway at full pool ................................................................. 1-7

Photo 2-1 Aerial view of Henry Hagg Lake and surrounding foothills and

Coastal Mountain Range......................................................................................... 2-1

Photo 2-2 Shoreline erosion near Elks Picnic Area................................................................. 2-8

Photo 2-3 Shoreline erosion control structure at Sain Creek Picnic Area (at low pool) ......... 2-8

Photo 2-4 Grasslands, mixed forest, coniferous forest, and clearcuts as seen from Henry Hagg Lake ................................................................................. 2-16

Photo 2-5 Riparian vegetation along Scoggins Creek ........................................................... 2-20

Photo 2-6 Henry Hagg Lake and surrounding landscape (at full pool)................................. 2-37

Photo 2-7 View of Henry Hagg Lake and Scoggins Creek at low pool (October 2001) ...... 2-37

Photo 2-8 View of Nelson Cove area .................................................................................... 2-37

Photo 2-9 View of Recreation Area C fishing pier from upland meadow ............................ 2-37

Photo 2-10 View of Henry Hagg Lake and Scoggins Creek area at high pool (April 2002) .. 2-38

Photo 3-1 Scoggins Dam at low pool (October 2001)............................................................. 3-1

Photo 3-2 Scoggins Dam, spillway, and operations facilities below the dam......................... 3-2

Photo 3-3 Aerial view of Recreation Area C (center) and adjacent Cove Area (right)......... 3-13

Photo 3-4 Recreation Area A West, as seen from the water ................................................. 3-13

Photo 3-5 Scoggins Creek Picnic Area.................................................................................. 3-17

Photo 3-6 Recreation Area C fishing pier as seen from the water ........................................ 3-17

Photo 3-7 Fishing pier during low water as seen from adjacent Cove Area ......................... 3-17

Photo 3-8 The Torvend Pavilion at Sain Creek Picnic Area ................................................. 3-18

Photo 3-9 Out for a day of fishing on the reservoir............................................................... 3-19

Photo 3-10 Bank fishing at Sain Creek Picnic Area................................................................ 3-19

Photo 3-11 Bicyclists take a break to enjoy the view over the reservoir................................. 3-19

Photo 3-12 ODFW sponsored “Free Fish Day” at Recreation Area C.................................... 3-23

Photo 3-13 Learning the art of casting during Free Fish Day ................................................. 3-23

Photo 3-14 The “Master Trail” located adjacent to the reservoir............................................ 3-26

Photo 3-15 A portion of the Master Trail that runs through trees and over a creek................ 3-26

Photo 3-16 The fishing pier is accessible to all visitors .......................................................... 3-27

Photo 4-1 While on a site tour, the AHWG stops to discuss the proposed Education and Research Center on the meadow overlooking Nelson Cove............................ 4-4

Photo 4-2 The AHWG discussing resource issues at Scoggins Creek Picnic Area ................ 4-4

Photo 4-3 Members of the planning team and AHWG discussing some of the details in the alternatives developed as part of the RMP planning process ....................... 4-4

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1vi1 T A B L E O F C O N T E N T S May 2004

Acronyms and Abbreviations af Acre-foot AF-10 Agricultural Forest – 10 (Land Use Designation) AF-20 Agricultural Forest – 20 (Land Use Designation) AF-5 Agricultural Forest – 5 (Land Use Designation) AINW Archaeological Investigations Northwest, Inc.

ARPA Archaeological Resources Protection Act BLM Bureau of Land Management BMP Best Management Practice BOD Biological Oxygen Demand BP Before present CEQ Council on Environmental Quality CFR Code of Federal Regulations cfs Cubic feet per second COE U.S. Army Corps of Engineers CWA Clean Water Act CWS Clean Water Services dB Decibel dBA a-weighted decibel DLUT Department of Land Use and Transportation DM Department Manual DO Dissolved oxygen EA Environmental Assessment EFC Exclusive Forest and Conservation (Land Use Designation) EFU Exclusive Farm Use (Land Use Designation) EIS Environmental Impact Statement EO Executive Order ESA Endangered Species Act ESU Evolutionarily Significant Unit FONSI Finding of No Significant Impact FWCA Fish & Wildlife Coordination Act GRFD Gaston Rural Fire Department HR House Rule HUWC Hillsboro Utility Water Commission IPM Integrated Pest Management ITA Indian Trust Asset IWG Interagency Work Group LOS Level of Service mph Miles per hour MPN Most Probable Number NAGPRA Native American Graves Protection and Repatriation Act National Register National Register of Historic Places NEPA National Environmental Policy Act NGO Non-Government Organization NHPA National Historic Preservation Act NMFS National Marine Fisheries Service

May 2004 T A B L E O F C O N T E N T S 1vii1

Acronyms and Abbreviations (continued) NOI Notice of Intent NPDES National Pollutant Discharge Elimination System NPS National Park Service NRCS Natural Resources Conservation Service NTU Nephelometric Turbidity Unit O&M Operations & Maintenance OAR Oregon Administrative Rules ODA Oregon Department of Agriculture ODEQ Oregon Department of Environmental Quality ODF Oregon Department of Forestry ODFW Oregon Department of Fish & Wildlife ONHP Oregon Natural Heritage Program ORV Off-road vehicle PAM Planning Aid Memorandum PL Public Law PSU Portland State University PWC Personal watercraft Reclamation U.S. Bureau of Reclamation R-IND Rural Industrial RM River Mile RMP Resource Management Plan SC Sensitive Critical SHPO State Historic Preservation Office SoC Species of Concern SOD Sediment Oxygen Demand SU Sensitive Undetermined SV Sensitive Vulnerable TCP Traditional Cultural Property TES Threatened, Endangered, or Sensitive TVID Tualatin Valley Irrigation District USA Unified Sewerage Agency USFWS U.S. Fish & Wildlife Service USGS U.S. Geological Survey WACCCA Washington County Consolidated Communication Agency WACO Washington County, Facilities Management

1viii1 T A B L E O F C O N T E N T S May 2004

Chapter 1

Introduction

CHAPTER 1.0

INTRODUCTION

1.1 RMP Program and Policy

The Pacific Northwest Region of the Bureau of Reclamation (Reclamation) is conducting a multi-year program to prepare a Resource Management Plan (RMP) for each of its major facilities. This program is guided by Federal legislation and policies to ensure that Federal lands are managed to serve a wide range of public purposes. RMP preparation is specifi-cally authorized in Title 28 of Public Law 102-575. It is also an outcome of Assessment '87, a Reclamation study that examined the future direction of its programs. This study established a broad framework for moving forward into the 21st century, with increased emphasis on the improved management of projects and the protection of the environment.

Each RMP is intended to provide the man-agement framework needed to balance the de-velopment, use, and protection of Reclamation lands and their associated natural, cultural, and recreational resources. It is Reclamation's blueprint for future resource management de-cisions to guide Reclamation, managing part-ners, and agency cooperators, as well as in-form the public about the resource management policies and actions to be im-plemented over the life of the RMP.

Reclamation's resource management policy is to provide a broad level of stewardship to en-sure and encourage resource protection, con-servation, and multiple use, as appropriate.

Management practices and principles estab-lished in this RMP, in accordance with exist-ing Federal laws, regulations, and policies, provide for the protection of fish, wildlife, and other natural resources; cultural resources;

public health and safety; and applicable uses of Reclamation lands and water areas, public access, and outdoor recreation.

1.2 Purpose and Scope of the

Plan

The Henry Hagg Lake RMP is being prepared in cooperation with Reclamation’s non- Federal managing partner at Henry Hagg Lake

– Washington County, Facilities Management (WACO), the local agency responsible for managing recreation facilities on Reclamation lands at Scoggins Valley Park/Henry Hagg Lake.

The Henry Hagg Lake RMP is a 10-year plan to provide management direction for lands and waters under Reclamation jurisdiction in the vicinity of Henry Hagg Lake in Washington County, Oregon about 30 miles southwest of the city of Portland, Oregon. Collectively, the entire area is referred to as the “RMP study area” in this document.

Reclamation currently does not have an RMP for its lands around Henry Hagg Lake. The purpose of this RMP is to address current and anticipated future issues to permit the orderly and coordinated development and manage-ment of lands and facilities and the water sur-face under Reclamation jurisdiction in the RMP study area. The plan will be used as the basis for directing activities on Reclamation lands and the reservoir in a way that maxi-mizes overall public and resource benefits, and that provides guidance for managing the area during the next 10 years.

Through implementation of the RMP, Recla-mation aims to balance competing and con-

May 2004 C H A P T E R O N E I N T R O D U C T I O N 1-1 flicting demands for differing uses and to maximize compatibility with surrounding land uses, while affording an appropriate level of resource protection and enhancement.

Over the course of implementing the RMP, it will be reviewed, reevaluated, and revised (if necessary) in cooperation with all involved agencies and Tribes to reflect changing condi-tions and management objectives. If a pro-posed modification to the RMP would signifi-cantly affect area resources or public use, opportunities for public involvement will be provided. The RMP will be fully updated at the end of its 10-year life.

In addition to this introductory chapter, the RMP contains the five main chapters, summa-rized below.

Chapter 2 summarizes the relevant natural, visual, cultural, and socioeconomic resources around the reservoir. The resource inventory describes existing conditions and lays the framework for identifying suitable resources for a variety of land and water uses, as well as sensitive resources that require special protec-tion, enhancement, or restoration.

Chapter 3 summarizes existing land use and management. The range of existing land uses is described and existing land use agreements identified. These include: Project facilities and general operations (i.e., Scoggins Dam and Henry Hagg Lake); agreements, ease-ments and permits; encroachments; public fa-cilities, utilities and services; recreational uses; and access and transportation.

Chapter 4 provides a detailed description of the RMP planning process, including the pub-lic involvement program and input received through newsbrief response forms, meet-ings/workshops, and agency consultation.

This chapter also describes Reclamation’s ef-forts regarding its trust responsibilities to the affected Tribes. All of this information helped identify the range of issues and concerns, es-tablish goals and objectives, identify the range of alternative plans for study, and modify the Preferred Alternative, which became the

RMP.

Chapter 5 is the core of the RMP and provides a detailed description of the Goals, Objectives, and Management Actions associated with the plan. The Goals, Objectives, and Manage-ment Actions are organized according to the following six themes: (1) natural resources;

(2) cultural resources; (3) Indian sacred sites;

(4) Indian Trust Assets; (5) recreation and ac-cess; and (6) land use, management, and im-plementation.

Chapter 6 presents the implementation pro-gram associated with the Management Actions set forth in Chapter 5. This includes a de-scription of program phasing, related actions, priorities, and responsible entities, as well as the process involved with amending and up-dating the plan.

1.3 Relationship to Tualatin

Valley Water Supply Feasibility Study

Clean Water Services (CWS) is a wastewater service agency serving 122 square miles in urban Washington County, small portions of Portland and Lake Oswego, and parts of Multnomah and Clackamas Counties. In re-sponse to increasing water use demands in the Tualatin River Basin, CWS, in cooperation with several municipalities and Tualatin Val-ley Irrigation District (TVID), is preparing a Water Supply Feasibility Study (WSFS) and associated Environmental Impact Statement (EIS) to study alternatives for increasing water supply in the Tualatin River Basin. Reclama-tion is providing technical assistance in as-sessing alternative water supply source op-tions, which include:

• Expansion of Henry Hagg Lake by raising Scoggins Dam 20 feet;

1-2 C H A P T E R O N E I N T R O D U C T I O N May 2004

• Expansion of Henry Hagg Lake by raising Scoggins Dam 40 feet; and

• Exchange of Willamette River water for irrigation.

Options to be considered as components of all supply alternatives involve water conserva-tion, waste water reuse, aquifer storage and recovery, and near-term additional supply from Portland. A No Action Alternative will also be analyzed.

The WSFS was started in November 2001 as a collaborative effort led by CWS. A preferred alternative is scheduled to be identified in the summer of 2004. In preliminary studies, sci-entists and engineers identified potential water sources to be evaluated. These potential sources and the planned WSFS approach were presented for public review and comment dur-ing scoping meetings in January 2002. Sub-sequently, it is planned that information on alternatives, impacts, and possible mitigation will be presented to the general public for re-view. Public comments will become part of the body of knowledge used in selecting a pre-ferred alternative. Because the preferred al-ternative might involve Federal action, the study will complete the investigation and analysis necessary to develop a Planning Re-port and Environmental Impact Statement (PR/EIS) pursuant to NEPA. A draft PR/EIS would be presented to the public for comment under this scenario.

Raising the dam 20 or 40 feet would inundate most recreation facilities at, and portions of the road around, Henry Hagg Lake. While long-range timing is difficult to predict, im-plementation of the WSFS preferred alterna-tive may occur in 2008, within the planning period for this RMP. Outcomes from the WSFS that would affect Henry Hagg Lake would be considered in the next RMP process.

To ensure full coordination among the inter-ested parties, both CWS and TVID were rep-resented on the Ad Hoc Work Group for the Henry Hagg RMP process (see Section 4.0 for more information on the role of the Ad Hoc Work Group).

This RMP was developed with the under-standing that the potential dam raise project at Henry Hagg Lake would replace any affected recreation amenities (including structures, trails, parking, roadways, infrastructure, and land) on a like-for-like basis as part of the cost of that project. Such expenditure would not be subject to cost sharing by Reclamation.

This RMP recognizes that it would not be in the public’s interest to invest in substantial recreation development at Scoggins Valley Park that does not currently exist as of January 1, 2004 and would need to be replaced if the dam were raised. Therefore, recreational de-velopment improvements prior to the final de-cision on the dam raise will concentrate on elements that are portable and/or do not re-quire large capital expenditures for permanent facilities.

In addition, Reclamation, WACO, and ODFW have developed a plan for maintaining and monitoring the elk meadows located around Henry Hagg Lake and just downstream of the dam in the Reclamation Zone. Some of these elk meadows could be inundated from a dam raise, depending on the height of the dam im-provement. Similar to recreation resources, this RMP assumes that inundated elk mead-ows would be replaced in the vicinity of Henry Hagg Lake, and that these costs are not subject to cost-sharing with Reclamation. The two new elk meadows that will be developed under this RMP will be out of the zone of in-fluence from any dam raise.

1.4 Location and Description of

the RMP Study Area

Henry Hagg Lake is located in western Wash-ington County, Oregon, approximately 30 miles southwest of the city of Portland. The study area lies within the 38-square-mile drainage ba-sin of Scoggins Creek, in the foothills of the Oregon Coast Range. The reservoir is an impor-

May 2004 C H A P T E R O N E I N T R O D U C T I O N 1-3 tant recreation resource in the region, both for local residents as well as those from the Portland metropolitan area. As the region continues to grow, Reclamation expects that more people will use the area. This increasing recreation use, as well as the potential conflicts among recrea-tion, aesthetic, and natural resources, is an im-portant reason for preparing a management plan for the area’s resources

As shown in Figure 1.4-1, the RMP study area consists of Reclamation-owned lands surround-ing Henry Hagg Lake. Reclamation’s jurisdic-tion includes Henry Hagg Lake (1,132 acres) and adjacent lands (1,449 acres). Reclamation lands generally consist of a strip of land around the reservoir with about 11 miles of shoreline.

Lands surrounding the Reclamation lands are a patchwork of private and Federal lands, includ-ing several private residences directly adjacent to Scoggins Valley Park.

Primary road access to Henry Hagg Lake is pro-vided by Highway 47 and Scoggins Valley Road.

Photo 1-1. Aerial view of Scoggins Dam, Henry Hagg Lake, and surrounding area.

1.5 Project Summary

Construction on Henry Hagg Lake began in 1972 and was completed in 1975 to provide irri-gation service for the Tualatin Valley, municipal and industrial water supply for eight communi-ties, flood control, recreation opportunities, maintenance of water quality, and fish and wild-life enhancement. Henry Hagg Lake is part of

Reclamation’s Tualatin Project, which supplies irrigation water to the Tualatin Valley, supplies municipal water to local communities, and pro-vides flood control. With a surface area of 1,132 acres, the reservoir has a storage capacity of 59,950 acre-feet (af). The reservoir and sur-rounding park are owned by the United States, under Reclamation’s jurisdiction, while water-related recreation features, natural resources, and lands of the surrounding park are managed, operated and maintained by WACO, Reclama-tion’s non-Federal managing partner. The park features many day use picnic areas, two boat launches, a fishing pier, and several miles of trails. In 1973, WACO entered into a 50-year lease agreement with Reclamation for admini-stration of Scoggins Valley Park for public out-door recreation use and for fish and wildlife en-hancement. Planning for the park facilities was done by the National Park Service (NPS) in 1970. Using the NPS plan, work began on park recreational facilities in 1975. As the facilities became available, they were opened for use by the public. The last NPS plan based facility was completed in 1978. Due to an increase in popu-larity and recreational use during the 1980s, WACO developed a Master Plan (1989) that identified additional or not yet developed recrea-tional facilities to meet this growing demand. A 1994 NEPA EA evaluated three management options for Henry Hagg Lake (Reclamation 1994). The preferred alternative was chosen and provides the guidance under which the park has been managed. This RMP supersedes manage-ment under the 1994 EA. The park is open for day use from the first Saturday in March through the last Sunday prior to Thanksgiving.

1-4 C H A P T E R O N E I N T R O D U C T I O N May 2004

Scoggins Creek Picnic Area

Boat Ramp/Recreation Area "C"

Sain Creek Picnic Area

W es t S ho re

D riv e

Lee

Ro ad

T o P att on V a ll e y

Sain Creek Road

S coggins V alley R oad

H e n r y

H a g g

C r e e k

S a i n Creek

Ta nn er a l l C r e e k

B u o y

NO WAKE AREA

NO-WAKE AREA

Rec

Elks Picnic Area

Recreation Area "A" East

Boat Ramp/Recreation Area "A" West

STIMSON

MILL

Park Administrative Office & Maintenance Yard

To Hwy 47

Herr Road

L a k e

SCOGGINS

DAM

L i n e

Zonelamation

RMP Study Area Figure 1.4-1 Existing Park Facility or Recreation Site

Recreation Site - Out of Use (Closed)

Reclamation Boundary

Reclamation Zone

Recreation Trail Road Stream

1:33,000

VHenry Hagg Lake RMP

Source: USBR, USGS, TRWC, EDAW, 2003 P:\1e41401_Henry_Hagg\GIS\Project\mxd\RMP\Figure1.4-1.mxd

Back of Figure 1.4-1

1-6 C H A P T E R O N E I N T R O D U C T I O N May 2004

Photo 1-2. Scoggins Dam and spillway at full pool.

1.6 Overview of Public Involve-

ment, Agency, and Tribal Coordination

Reclamation conducted an extensive public involvement program as part of the RMP plan-ning process to ensure representation and par-ticipation by all those interested in the future of Henry Hagg Lake. To achieve full repre-sentation, the program was designed to reach a user population that was dispersed over a broad geographical area, representing diverse points of view, and enthusiastic in participat-ing in the RMP planning process.

The public involvement program consisted of four primary elements: (1) four newsbriefs mailed to agencies, Tribes, elected officials, organizations, media, and individuals; (2) two public meetings/workshops; (3) four meetings with a group formed as part of the RMP plan-ning process to represent key stakeholders (in-cluding agencies, Tribes, and interest groups in the area); and (4) a public web site provid-ing access to newsbriefs, draft materials, and meeting announcements. These elements, as well as additional agency and Tribal consulta-tion efforts, are discussed in further detail in Chapter 4.

May 2004 C H A P T E R O N E I N T R O D U C T I O N 1-7

1-8 C H A P T E R O N E I N T R O D U C T I O N May 2004

Chapter 2

Existing Conditions

CHAPTER 2.0

EXISTING CONDITIONS

2.1 Natural Resources

2.1.1 Climate

The climate of the Scoggins Valley is rela tively mild throughout the year, characterized by cool, wet winters and warm, dry summers.

The climatic conditions closely resemble the Mediterranean climates that occur in Califor nia, although Oregon’s winters are somewhat wetter and cooler. Similar to most of Oregon, the Scoggins Valley has a predominant winter rainfall climate. Typically about 50 percent of the annual total precipitation falls from De cember through February, with lesser amounts in the spring and fall, and with very little dur ing the summer.

There is considerable variation in precipitation within the Willamette Valley ranging from annual totals below 40 inches in the Portland area to upwards of 80 inches in the Cascade and Coast Range foothills. Elevation is the most important determinant of precipitation totals. Extreme temperatures in Scoggins Val ley are rare; only about 5 days on average per year are at or above 90 degrees (F) and about 51 days a year have temperatures below freez ing. Snow fall is limited to about 5 inches per year (Oregon Climate Service 2002). Winters are likely to be cloudy with an average of 80 percent cloud cover during the coldest months.

Twenty six days are generally cloudy in Janu ary for instance. During the summer sunshine is more abundant with average cloud cover less than 40 percent and more than half the days in July are clear.

The Scoggins Valley area is in attainment with federal air quality standards (Oregon Depart ment of Environmental Quality 2002). The general vicinity is rural and other than the nearby lumber mill there are few pollution generators. Henry Hagg Lake is outside of the nearby Portland Metropolitan Service District, which extends west as far as Forest Grove.

This district is considered a maintenance area by the U.S. Environmental Protection Agency because it had a history of non-attainment of air quality standards but is currently meeting these standards.

2.1.2 Topography

Much of the land surrounding the reservoir is hilly and has slopes of 20 percent or greater (Figure 2.1-1) (Reclamation 1994). Eleva tions within the park range between 180 and 450 feet but adjacent features extend to above 1,000 feet. Level areas can be found adjacent to the reservoir particularly between Scoggins and Tanner Creeks and north of the Sain Creek cove. In many areas moderate slopes lead from the reservoir edge at full pool (Photo 2-1).

Photo 2-1. Aerial view of Henry Hagg Lake and surrounding foothills and Coastal Mountain Range.

May 2004 C H A P T E R T W O E X I S T I N G C O N D I T I O N S 2-1

The creeks leading into the reservoir flow through narrow, often steep canyons. Down stream of the dam Scoggins Creek flows through a wide, level valley dominated by ag riculture.

2.1.3 Geology

Henry Hagg Lake and the Scoggins Creek drainage basin lie on the eastern side of the Coast Range. The geology in the area consists of Tertiary volcanic rocks and marine sedi ments. The volcanics consist of basaltic flows and the sediments are poorly indurated (ce mented into a hard mass) marine sandstone, shale, siltstone, and claystone.

There are four distinguishable formations that comprise most of the drainage area. These include, in order of decreasing age, the Lower Eocene Siletz River Formation (pillow flows and breccia), the Middle Eocene Yamhill Formation (cemented siltstone and claystone), the Upper Eocene Tillamook Volcanics (basalt flows), and Tertiary Intrusive Rocks that con sist primarily of dikes and sills of basalt (Rec lamation 2000).

Extensive weathering of the Tertiary forma tions has occurred as the result of precipitation and time. Outcrops of unweathered rock are rare and the degree of weathering is more or less uniform in depth throughout the area.

Weathering generally ranges from 20 to 30 feet in depth below ground surface. The re sidual soil is composed of soft, tan to brown, moist, lean to fat clay to clayey sand with scattered decomposed fragment of sedimen tary and volcanic rock. A thin surface layer of topsoil mantles the residual soil. The topsoil consists of organic silt with lesser amounts of fine sand (Reclamation, 2000)

2.1.4 Soils

Soils in the vicinity of Henry Hagg Lake are derived from the weathered marine sediments and volcanic rocks that form the east slopes of the Coast Range. Soil profiles in the area generally consist of a thin layer of topsoil mantling a deeper layer of residual soils. Area topsoil is composed of organic silt with lesser amounts of fine sand. The underlying sedi ments consist of material formed from exten sive weathering and mixing of the existing marine sediments with the Tertiary volcanic rock formations. This residual soil is gener ally well-drained and characterized by a soft, tan-to-brown, moist, clay-to-clayey sand with scattered decomposed fragments of sedimen tary and volcanic rock (Reclamation 2000).

The moderately steep topography of the Scoggins Valley, coupled with the extensive annual precipitation, has resulted in area soil deposits created largely through alluvial proc esses. The 14 soil types that occur in the vi cinity of Henry Hagg Lake are listed in Table 2.1-1 and illustrated in Figure 2.1-2 (USDA 1982). The specific locations of occurrence of soil types in and around Scoggins Valley Park are shown in Figure 2.1-1.

Many of the soil types located on the steeper slopes (>10%) in the study area represent moderate to severe erosion hazards. In gen eral, the geologic process of sediment accu mulation that resulted in the formation of the majority of study area soil types also resulted in soil characteristics conducive to erosion.

Subsurface material formed from alluvial (re lated to surface water), colluvial (sediment deposited at the base of slopes), and eolian (wind-weathered) processes tend to be non-cohesive and subject to slippage along steep slopes. However, these same soil types tend to be well-drained with slow runoff in more level areas, which may mitigate the potential for erosion.

Soil erosion in surrounding lands and the re sulting deposition of sediments into Henry Hagg Lake have been long-standing concerns of land managers (Photos 2-2 and 2-3). In planning for park development prior to the construction of Scoggins Dam, potential sediment yield and lost reservoir capacity

2-2 C H A P T E R T W O E X I S T I N G C O N D I T I O N S May 2004

H e n r y

H a g g

L a k e

Creek

C ek

Sain Creek

Ta nn e r

Scoggins

W al l C ek es t S e

To Hwy 47

Lee

R oa d

To P at to n

V al le y

Sain Creek Road

S coggins V alley R oad

Buo y L i ne

NO-WAKE AREA

Figure 2.1-1 Slope and Hydrography

Scoggins Creek Picnic Area

Elevation (feet)

Approximate High Pool - 305 ft.

Approximate Normal Pool - 285 ft.

Approximate Low Pool - 220 ft.

Other Open Water

Stream

Original Stream-Bed Topography

Road

Recreation TrailBoat Ramp/Recreation Area "C" Recreation Site - In Use

Recreation Site - Out of UseHerr Road

Boat Ramp/Recreation Area "A" West Park Facility

Reclamation Boundary

V Sain Creek Picnic Area

Recreation Area "A" East

0 00.25

Miles

1,000 2,000 3,000 4,000 5,000

Feet

Park Administrative Office & Maintenance Yard

1:20,000

SCOGGINS

DAM

Henry Hagg Lake RMP

STIMSON

MILL

Elks Picnic Area

Source: USBR 1999, USGS, TRWC, EDAW, 2003 P:\1e41401_Henry_Hagg\GIS\Project\mxd\RMP\Figure3.x-x.mxd

.5

Source: USBR 1999, USGS, TRWC, EDAW, 2003 P:\1e41401_Henry_Hagg\GIS\Project\mxd\RMP\Figure2-1-2.mxd

Soils

Figure 2.1-2

Henry Hagg Lake RMP

1:20,000

V 0 0.25

Miles

H e n r y

H a g g

L a k e

Creek

C re ek

Sain Creek

Ta nn er

Scoggins

SCOGGINS

DAM

W al l C re e

W es t S e

To Hwy 47

Lee

Ro ad

To P at to n

V al le y

Sain Creek Road

Herr Road

S coggins V alley R oad

Buo y L ine

NO-WAKE AREA

Scoggins Creek Picnic Area

Boat Ramp/Recreation Area "C"

Sain Creek Picnic Area

Elks Picnic Area

Recreation Area "A" East

Boat Ramp/Recreation Area "A" West

Soil Types

CARLTON SILT LOAM

CHEHALEM SILTY CLAY LOAM

CHEHALIS SILT LOAM

CHEHALIS SILTY CLAY LOAM

HELVETIA SILT LOAM

LAURELWOOD SILT LOAM

MCBEE SILTY CLAY LOAM

MELBOURNE SILTY CLAY LOAM

OLYIC SILT LOAM

PERVINA SILTY CLAY LOAM

SAUM SILT LOAM

TOLKE SILT LOAM

UDIFLUVENTS

WAPATO SILTY CLAY LOAM

NO DATA

Reclamation Boundary

Recreation Trail

Recreation Site - In Use

Recreation Site - Out of Use

Road

Stream

Open Water (normal pool, approximately 285')

0.5

Table 2.1-1: Soil types adjacent to Henry Hagg Lake.

Map Unit Soil Type Slope Depth to Bedrock Erosion Hazard Soil Characteristics 6B Carlton Silt

Loam 0-7% >65 in slight-moderate moderately well-drained silty clay loam; permeability is moderate to slow

8C Chehalem Silty Clay

Loam

3-12% >50 in slight-moderate gently sloping to moderately steep on alluvial fans; runoff is slow to medium, 10 Chehalis Silt

Loam Nearly level >60 in slight well-drained, silt loam surface with heavy silt loam subsoil;

runoff slow

Chehalis Silty Clay Loam

Nearly level

>60 in slight deep, well-drained; runoff slow; located on smooth flood plains

19B,C,D,E Helvetia silt loam

2-30% >60 in slight-severe (de-pending upon slope) moderately well-drained; mod-erately slow permeability;

slightly acid; four soil types and map units based on slope

29B,C,D,E, F

Laurelwood Silt Loam

3-60% >70 in slight-severe (de-pending upon slope) deep,…