Suislaw EA_w all signatures (June 2024).pdf

FINAL ENVIRONMENTAL ASSESSMENT

United States Coast Guard Construct Covered Moorings and Correct Shoreline Erosion at Station Siuslaw River Final Environmental Assessment

June 2024

UNITED STATES COAST GUARD (COAST GUARD) FINDING OF NO

SIGNIFICANT IMPACT (FONSI) FOR CONSTRUCT COVERED MOORINGS

AND CORRECT SHORELINE EROSION AT STATION SIUSLAW RIVER

PROJECT

The United States Coast Guard (USCG) proposes to replace infrastructure needed to protect land based assets and inwater infrastructure at its station near the mouth of the Siuslaw River in Florence, OR. The Proposed Action would reinforce the shoreline to reduce erosion and would replace an aging boathouse that is used as a mooring for motor lifeboats. Pursuant to the National Environmental Policy Act (NEPA), the USCG has prepared an Environmental Assessment (EA) to evaluate the potential environmental, cultural, and socioeconomic effects of the Proposed Action as well as the No Action Alternative.

The Proposed Action consists of three main components: 1) construction of an interlocking steel pile wall above the elevation of the Siuslaw River estuary 50-year extreme tide level as a durable, long-term solution to correct shoreline erosion and stabilize the sand bluff, 2) demolition and construction necessary to replace the boathouse and appurtenant structures including piles, piers, and utilities with state-of-the-art structures designed to withstand elements of the Siuslaw River estuary environment, and 3) a temporary mooring and ready crew housing component in Florence at the Port of Siuslaw Campground and Marina during the replacement of the covered mooring.

Summary of the Results of the Environmental Impact Evaluation: Based on the analysis presented in the EA, the Proposed Action would not result in any significant impacts to the human environment. The Proposed Action would result in minor long-term adverse impacts on biological resources, visual resources, utilities, noise, recreation, and socioeconomics. The Proposed Action would also result in minor impacts on some resources during construction, including air quality, visual resources, utilities, geology and soils, hazardous materials, noise, recreation, socioeconomics, transportation, hazardous materials, and utilities. The Proposed Action would result in moderate short-term adverse impacts on biological resources and noise.

Mitigation measures identified in the attached EA would reduce the potential for impacts to biological resources and hazardous materials. The Proposed Action would result in minor short-term beneficial impacts on socioeconomics.

If unforeseen significant or potentially significant impacts are found once the Proponent completes compliance with related environmental or historic resource laws and regulations, the Proponent will supplement or amend the attached contractor-prepared EA, or will prepare a new and higher level environmental planning document.

The USCG will complete compliance with other environmental laws and regulations prior to initiation of any construction. Compliance actions include:

- US Army Corps of Engineers permit under Section 404 of the Clean Water Act and/or Section 10 of the Rivers and Harbors Act for construction within waters of the United States.

-A water quality certification from the Oregon Department of Environmental Quality under Section 401 of the Clean Water Act (pending).

- Federal consistency review under the Coastal Zone Management Act, including submittal of a Coastal Consistency Determination to the Oregon Department of Land Conservation and Development, is pending.

- Consultation with US Fish and Wildlife Service and National Oceanic and Atmospheric Administration (NOAA) National Marine Fisheries Service under Section 7 of the Endangered Species Act has been initiated.

- Consultation with National Marine Fisheries Service and the request of an Incidental Harassment Authorization pursuant to the Marine Mammal Protection Act has been initiated.

- Coordination with NOAA on any additional measures, if necessary, to avoid adverse effects on Essential Fish Habitat pursuant to the Magnuson-Stevens Fishery Conservation and Management Act has been initiated.

- Consultation with the Oregon State Historic Preservation Officer pursuant to Section 106 of the National Historic Preservation Act regarding potential adverse effects on cultural and historical resources has been completed.

- Oregon Department of State Lands Removal-Fill Permit for dredging and backfilling pier access areas has been reviewed and is subject to public comment.

- Oregon Department of Fish and Wildlife Fish Passage Approval is pending.

Mitigation Commitments (Including Monitoring), if any, that will be Implemented to Reduce Otherwise Significant Impacts: No significant impacts have been identified that require mitigation. Standard mitigation or monitoring commitments have been included in the Proposed Action. The Proposed Action includes standard protocols and best management practices that are part of all CG construction projects to reduce potential impacts, especially during construction. In addition, further control measures for the protection of the environment are likely to be required for the Proposed Action as part of the compliance actions to be completed during the final design phase.

This FONSI is based on the attached contractor-prepared EA, which has been independently evaluated by the USCG and determined to adequately and accurately discuss the environmental issues and impacts of the Proposed Action and provide sufficient evidence and analysis to determine that an Environmental Impact Statement is not required. The USCG takes full responsibility for the accuracy, scope, and content of the attached contractor-prepared FEA.

I reviewed the EA, which is the basis for this FONSI, and submitted my written comments to the Proponent.

Construction Project Manager Level I_______ Elizabeth Simione Title/Position NEPA Warrant Program Document Preparer

Environmental Engineer Level II______ Richard D. Hylton. P.E. Title/Position NEPA Warrant Program Environmental Reviewer

Environmental Engineer Level II______ Richard D. Hylton. P.E. Title/Position NEPA Warrant Program Senior Environmental Reviewer

In reaching my decision/recommendation on the Coast Guard’s proposed action, I considered the information contained in this EA/FONSI and considered and acknowledge the written comments submitted to me from the Environmental Reviewer(s). Based on the information in the EA and this FONSI document, I agree that the proposed action as described above, and in the EA, will have no significant impact on the environment.

_________________________________Captain/Commanding Officer – FD&CC__________ Captain Neal E. Armstrong Title/Position Proponent

USCG Station Siuslaw River Final EA

June 2024 iii

EXECUTIVE SUMMARY

ES.1 Introduction

This Environmental Assessment (EA) has been prepared in accordance with the National Environmental Policy Act of 1969 (NEPA; 42 United States Code [USC] §§ 4321 et seq.); the President’s Council on Environmental Quality (CEQ) Regulations Implementing the Procedural Provisions of NEPA (40 Code of Federal Regulations [CFR] Parts 1500-1508); Department of Homeland Security (DHS) Management Directive 023-01, Implementation of NEPA; and in accordance with the USCG COMDTINST Environmental Readiness Program Manual OPNAV M-5090.1. This EA evaluates the environmental effects of the United States Coast Guard’s (USCG’s) proposal to correct shoreline erosion and replace the covered mooring and appurtenant offshore structures at the USCG Station Siuslaw River in the USCG Area of Responsibility District Thirteen at Florence, Oregon (Proposed Action) and its alternatives. The information and analysis contained within this EA were used to determine whether implementation of the Proposed Action would have a significant impact on the environment, requiring preparation of an Environmental Impact Statement (EIS). Since no significant impacts were identified, a Finding of No Significant Impact (FONSI) has been prepared.

ES.2 Scope of the Environmental Assessment

This EA evaluates the potential environmental effects of implementing the Proposed Action and reasonable alternatives. In accordance with NEPA and CEQ regulations, this EA considers two alternatives, as described in Section 2.1: the Proposed Action Alternative and No Action Alternative. This EA is a public document, and the analysis considers public input. The No Action Alternative is evaluated in accordance with the USCG COMDTINST Environmental Readiness Program Manual OPNAV M-5090.1. Existing conditions for resources at and in the vicinity of Station Siuslaw are described in Section 3.0. The potential impacts on these resources and proposed mitigation measures to prevent and minimize potential impacts are discussed in Section 4.0. USCG Facilities Design and Construction Center Seattle Detachment has prepared this EA to document, for other agency and public review, an analysis of the potential for adverse effects on the human environment from the Proposed Action and No Action Alternatives.

ES.3 Background

USCG Station Siuslaw River is located atop a sand bluff on the east shoreline of the Siuslaw River estuary where it was first established in 1917. It has onshore facilities including an administration and operations building with berthing for on-duty personnel, service buildings, parking areas, and eight housing units for active-duty personnel. Offshore facilities including a covered mooring that is approximately 52 years old with floating docks and floating debris boom provide covered and open berths for two 47-foot Motor Lifeboats and one 29-foot Response Boat

– Small.

June 2024 iv

Erosion of the shoreline and loss of the river bottom sediments caused by river currents, tidal and wave energy, and changes in river structure threaten the stability of the onshore and offshore facilities. Overland stormwater flows, increased through the years by area development and urbanization, also contribute to sediment removal from the sand bluff to exacerbate erosion.

Temporary slope stabilization repairs and efforts to reinforce existing offshore structures through installation or replacement of steel piles have occurred within the last two decades. Such efforts have slowed erosion and allowed for continued use of the covered mooring under most environmental conditions. However, to enable the USCG to maintain operations while preventing a future failure of the sand bluff and shoreline along the property, permanent solutions that address groundwater flow, erosive forces associated with the tidal riverine environment, scour of the riverbed, and covered mooring structural deficiencies are needed to mitigate the long-term effects.

In 2018, the USCG prepared an Environmental Feasibility Study that evaluated the feasibility of numerous alternatives to correct shoreline erosion and two alternatives for replacing the covered mooring. To assist the USCG with identifying a preferred alternative, the study presented the potential environmental impacts, identified the key permits, required reviews, and stakeholders, and discussed potential mitigation options for the alternatives to correct shoreline erosion and replace the covered mooring.

ES.4 Purpose and Need

The purpose of the Proposed Action is to construct a permanent solution to ongoing streambank erosion, replace structures that have become hazardous due to changing environmental conditions, and update infrastructure to accommodate new and necessary equipment.

The Proposed Action is needed to ensure optimum readiness and enable USCG D13 to safely perform its mission within its Area of Responsibility from the waterfront Siuslaw River location.

Should the USCG lose use of the covered mooring structure and waterfront operations, Motor Lifeboat and Response Boat-Small moorings would need to be permanently leased elsewhere upstream which would significantly increase response times and decrease mission effectiveness.

The primary mission of USCG Station Siuslaw River is search and rescue operations for recreational and commercial mariners from the Siltcoos River to Cape Perpetua along the Oregon Coast. Active-duty personnel further contribute to public safety by providing or assisting with towing and marine salvage operations, enforcing boating safety regulations and maritime laws, and performing functions for environmental protection and fisheries conservation.

ES.5 Description of the Proposed Action

The Proposed Action consists of three main components: 1) construction of an interlocking steel pile wall above the elevation of the Siuslaw River estuary 50-year extreme tide level as a durable, long-term solution to correct shoreline erosion and stabilize the sand bluff, 2) demolition and construction necessary to replace the boathouse and appurtenant structures

June 2024 v including piles, piers, and utilities with state-of-the-art structures designed to withstand elements of the Siuslaw River estuary environment, and 3) a temporary mooring and ready crew housing component in Florence at the Port of Siuslaw Campground and Marina during the replacement of the covered mooring.

Shoreline stabilization would be accomplished with installation of a steel interlocking pile wall placed above the 50-year calculated extreme tide elevation and aligned parallel along approximately 400 feet of the Siuslaw River. Additional riprap to supplement the existing riprap revetment would be installed to address erosion on the downslope side of the pile wall, but above the Mean Higher High Water mark. The Station’s stormwater management system will be improved to meet City of Florence standards. These rigid and structural components will implement a long-term solution to prevent further landward erosion and retain dune sands while allowing for free-draining groundwater flows to the river.

A new 6,470 square foot, two-bay covered mooring with engineering shop, storage areas, small marine diesel fueling facility, interior floating dock, fixed debris boom, and covered mooring access bridge will be constructed. Construction will occur in approximately the same positions as the original structures, but the new covered mooring structure will require a larger footprint to accommodate the larger USCG vessels proposed for use. New and state-of-the-art marine fuel delivery conveyances between the upland diesel and gasoline storage tanks and the landward end of the covered mooring access bridge, fueling safety controls, and electrical modifications are also included.

Project design and environmental clearances are ongoing and dependent upon environmental and regulatory timelines, the USCG anticipates a construction duration of two years beginning in the third quarter of 2024. In-water work for the covered mooring components will occur during the agency designated in-water work window from November 1 to February 15 for the protection of fish, wildlife, and habitat resources.

ES.6 Agency and Public Involvement

Pursuant to the requirements of NEPA (40 CFR 1506.6), this EA is subject to public involvement. Agencies, organizations, and members of the public with a potential interest in the Proposed Action have been invited and encouraged to participate. The USCG published a Notice of Intent (NOI) to prepare an EA in The Siuslaw News on July 2, 2022. The USCG also directly notified stakeholders—including Federal, state, and local government agencies, Tribal organizations, and regulatory bodies—via electronic correspondence of its intent to prepare an EA. The USCG encouraged interested parties to review the Proposed Action and provide comments or additional information during the 30-day scoping period which started upon publication of the NOI. No comments were received from the Confederated Tribes of Coos, Lower Umpqua, and Siuslaw Indians or the Confederated Tribes of Siletz Indians of Oregon during the 30-day scoping period. Six comments were received from five sources including an adjacent homeowners’ association, Lane County, and three federal government agencies. The

June 2024 vi commenters requested that the USCG maintain regular communication regarding project planning and execution.

The USCG also held an agency coordination meeting with federal, state, and local planning and permitting agencies on May 18, 2022. Representatives from seven agencies attended and provided initial comments on their expectations for environmental documentation.

The Draft EA was circulated for a 30-day public comment period running from March 6 to April 5, 2024. Comment letters or emails were received from five members of the surrounding community who expressed concerns about the proposed action’s potential impacts on their properties. Comments were also received from U.S. EPA Region 10. The Bonneville Power Administration submitted an email saying that they had no comments. All comments and the USCG’s responses are listed in Appendix A.

ES.7 Summary of Potential Environmental Consequences

A summary of the environmental impacts of each alternative is provided in Table ES-1-1. The analysis assumes that best management practices (BMPs) included as standard provisions of USCG contracts and project-specific conservation measures would be employed to avoid or minimize significant adverse effects on the environment. A complete list of conservation measures and BMPs is provided in Section 4.16. Implementing conservation measures and BMPs would ensure that the Proposed Action would avoid significant impacts or reduce potential impacts to less-than-significant levels.

Table ES-1-1. Summary of Impacts for the No Action and Proposed Action Alternatives

Impact Topic No Action Alternative Proposed Action Alternative

Aesthetics and Visual Resources

No effect Minor, short-term and long-term

Air Quality No effect Minor, short-term

Biological Resources Minor, long-term Minor to moderate, short-term and long-term

Climate Change No effect Negligible, short-term and long-term

Cultural Resources No effect Negligible, short-term and long term

Geology and Soils Moderate, long-term Minor, short-term; Beneficial, long-term

Hazardous Materials and Public Safety

Moderate, long-term Minor, short-term

June 2024 vii

Land Use No effect No effect

Noise No effect Moderate, short-term and long-term

Recreation No effect Moderate, short-term; Minor, long-term

Socioeconomics/EJ No effect Minor, short-term; Negligible, long-term

Transportation and Nav. No effect Minor, short-term

Utilities and Infrastructure

Moderate, long-term Minor, short-term and long-term

Water Resources No effect Minor, short-term and long-term

June 2024 viii

TABLE OF CONTENTS

EXECUTIVE SUMMARY ......................................................................................................................... iii

1 Purpose and Need For Action

1.1 Introduction

1.2 Background

1.3 Study Area Description

1.4 Purpose and Need for Action

1.5 Agency and Public Involvement

2 Proposed Action and Alternatives

2.1 Alternatives for Evaluation

2.1.1 No Action Alternative

2.1.2 Proposed Action Alternative

2.1.3 Alternatives Considered but Dismissed

3 Affected Environment

3.1 Land Use

3.1.1 Applicable Regulations

3.1.2 Zoning

3.1.3 Estuary and Coastal Shoreland Management Units

3.1.4 Current and Historical Uses and Ownership

3.2 Air Quality

3.2.1 Applicable Regulations

3.2.2 Air Quality Status

3.3 Climate Change

3.3.1 Applicable Regulations

3.3.2 Climate Change

3.4 Biological Resources

3.4.1 Applicable Regulations

3.4.2 Fish and Wildlife

3.4.3 Marine Mammals

3.4.4 Federal Threatened and Endangered Species and Essential Fish Habitat

3.4.5 Vegetation Communities

3.4.6 Wetlands and Other Waters of the United States

3.5 Water Resources

June 2024 ix

3.5.1 Applicable Regulations

3.5.2 Floodplain

3.5.3 Hydrology

3.5.4 Water Quality

3.6 Noise

3.6.1 Applicable Regulations

3.6.2 Noise Sources

3.7 Aesthetics and Visual Resources

3.7.1 Applicable Regulations

3.7.2 Visual Landscape

3.7.3 Designated Visual Resources

3.8 Geology and Soils

3.8.1 Soils and Sediments

3.8.2 Topography and Bathymetry

3.8.3 Seismicity

3.9 Cultural Resources

3.9.1 Applicable Regulations

3.9.2 Archeological and Historical Resources

3.10 Recreational Resources

3.10.1 Applicable Regulations

3.10.2 Recreational Resources

3.11 Socioeconomics and Environmental Justice

3.11.1 Applicable Regulations

3.11.2 Demographics

3.11.3 Employment and Housing

3.11.4 Healthcare and Education

3.11.5 Environmental Justice Communities

3.12 Transportation and Navigation

3.12.1 Applicable Regulations

3.12.2 Roadways, Rail, and Air

3.12.3 Waterways and Navigation

3.13 Utilities and Infrastructure

3.13.1 Utilities

3.13.2 Onshore and Offshore Station Infrastructure

June 2024 x

3.13.3 Temporary Mooring Utilities and Infrastructure

3.14 Hazardous Materials and Public Safety

3.14.1 Applicable Regulations

3.14.2 Hazardous Materials

3.14.3 Public Safety

3.14.4 Marine Rescue

4 Environmental Consequences

4.1 Land Use

4.1.1 No Action Alternative

4.1.2 Proposed Action Alternative

4.2 Air Quality

4.2.1 No Action Alternative

4.2.2 Proposed Action Alternative

4.3 Climate Change

4.3.1 No Action Alternative

4.3.2 Proposed Action Alternative

4.4 Biological Resources

4.4.1 No Action Alternative

4.4.2 Proposed Action Alternative

4.5 Water Resources

4.5.1 No Action Alternative

4.5.2 Proposed Action Alternative

4.6 Noise

4.6.1 No Action Alternative

4.6.2 Proposed Action Alternative

4.7 Aesthetics and Visual Resources

4.7.1 No Action Alternative

4.7.2 Proposed Action Alternative

4.8 Geology and Soils

4.8.1 No Action Alternative

4.8.2 Proposed Action Alternative

4.9 Cultural Resources

4.9.1 No Action Alternative

4.9.2 Proposed Action Alternative

June 2024 xi

4.10 Recreational Resources

4.10.1 No Action Alternative

4.10.2 Proposed Action Alternative

4.11 Socioeconomics and Environmental Justice

4.11.1 No Action Alternative

4.11.2 Proposed Action Alternative

4.12 Transportation and Navigation

4.12.1 No Action Alternative

4.12.2 Proposed Action Alternative

4.13 Utilities and Infrastructure

4.13.1 No Action Alternative

4.13.2 Proposed Action Alternative

4.14 Hazardous Materials and Public Safety

4.14.1 No Action Alternative

4.14.2 Proposed Action Alternative

4.15 Cumulative Impacts

4.15.1 No Action Alternative

4.15.2 Proposed Action Alternative

4.16 Mitigation Measures

4.16.1 No Action Alternative

4.16.2 Proposed Action Alternative

5 List of Preparers

6 Consultation and Coordination

6.1 Federal Compliance Requirements

7 References

LIST OF TABLES

Table ES-1-1. Summary of Impacts for the No Action and Proposed Action Alternatives......................... vi Table 3-1. Attainment Status for Lane County Table 3-2. ESA-listed Species Under USFWS Jurisdiction, Lane County, Oregon Table 3-3. NMFS ESA-listed Species With Potential to Occur in the Project Area Table 3-4. Summary of Previous Archaeological Studies within 1-mile of the Project Area Table 3-5. Population Table 3-6. Age and Sex

June 2024 xii

Table 3-7. Percent Race and Ethnicity Table 3-8. Language Table 3-9. Employment and Income Table 3-10. Percent Employment by Industry in the City of Florence, Lane County, the State of Oregon, and nationally across the U.S Table 3-11. Housing Table 3-12. Education, Health, and Service Table 4-1. Estimated Navigation Channeled Construction Sound Levels Table 4-2. Cumulative Projects and Plans Table 6-1. Compliance with Applicable Environmental and Cultural Resources Regulations

LIST OF FIGURES

Figure 1-1. View E-SE along sand bluff shoreline from Station’s exterior floating dock Figure 1-2. Project Vicinity Figure 1-3. Site Map Figure 2-1. Preliminary design of typical section for an interlocking wall Figure 3-1. City of Florence Zoning Figure 3-2. Flood Hazard Zone/Flood Insurance Rate Map (FIRM; FEMA 2022) Figure 3-3. Views of the Siuslaw River and in-water structures within the project area, facing west from the USCG Station Figure 3-4. Temporary mooring location (retrieved from Port of Siuslaw 2022) Figure 3-5. Damage from downslope hillside failure below Station parking area Figure 3-6. Sloughing dune in northwest corner of project area Figure 3-7. City of Florence Roadways, Airports, and Federal Navigation Channel

APPENDICES

A: Public Involvement Summary

B: Agency Correspondence

C: Preliminary Project Design Drawings https://tetratechinc.sharepoint.com/teams/PortlandProjects/Shared%20Documents/General/Projects/100-WTR-T42147%20USCG%20Station%20Siuslaw%20River/02%20Project%20Execution/06%20NEPA/11%20Preliminary%20Draft%20EA/USCG_StationSiuslaw_PrelimDraft_EA_10062023%20Draft.docx#_Toc147501958 https://tetratechinc.sharepoint.com/teams/PortlandProjects/Shared%20Documents/General/Projects/100-WTR-T42147%20USCG%20Station%20Siuslaw%20River/02%20Project%20Execution/06%20NEPA/11%20Preliminary%20Draft%20EA/USCG_StationSiuslaw_PrelimDraft_EA_10062023%20Draft.docx#_Toc147501959

June 2024 xiii

ACRONYMS

ACS

ADA

AOR

APE

BA

BGEPA

BGS

BMPs

CAA

CERCLA

CEQ

CFM

CFR

CSZ

CWA

CY

CZMA

D13 dBA

DEQ

DHS

DLCD

DPS

DSL

EA

ECSI

EFH

EFS

EIS

EL

EPA

ESA

ESU

FEMA

FMP

FNC

ft

GHG

GPM

H

HAPC

HAZMAT

American Community Survey Americans with Disabilities Act Area of Responsibility Area of Potential Effect Biological Assessment Bald and Golden Eagle Protection Act Below Ground Surface Best Management Practices Clean Air Act Comprehensive Environmental Response, Compensation, and Liability Act Council on Environmental Quality Cubic Feet per Minute Code of Federal Regulations Cascadia Subduction Zone Clean Water Act Cubic Yard Coastal Zone Management Act District 13 Decibels State of Oregon Department of Environmental Quality Department of Homeland Security Department of Land Conservation and Development Distinct Population Segment Oregon Department of State Lands Environmental Assessment Environmental Site Cleanup Information Essential Fish Habitat Environmental Feasibility Study Environmental Impact Statement Elevation Environmental Protection Agency Endangered Species Act Evolutionarily Significant Unit Federal Emergency Management Agency Fishery Management Plan Federal Navigation Channel Feet Greenhouse Gas Gallons per Minute Horizontal Habitat Areas of Particular Concern Hazardous Materials

June 2024 xiv

HMT

IHA

IPaC

IWWW

LF

LID

LWM

LRAPA

MBTA

MHHW

MLB

MLLW

MMPA

NAAQS

NAGPRA

NAVD88

NEPA

NHPA

NMFS

NOAA

NOI

NPDES

NRHP

OAR

OCMP

ODFW

ODOT

OHW

OHWM

OR

PFMC

PGIS

PM

PPE

PSO

RCRA

RB-S

RHA

RM

RV

SAR

SAV

SF

SHPO

SIP

Highest Measured Tide Incidental Harassment Authorization Information, Planning, and Conservation In-Water Work Window Linear Foot Low Impact Development Large Woody Material Lane Regional Air Protection Agency Migratory Bird Treaty Act Mean Higher High Water Motor Lifeboat Mean Lower Low Water Marine Mammal Protection Act National Ambient Air Quality Standards Native American Graves Protection and Repatriation Act North American Vertical Datum of 1988 National Environmental Policy Act National Historic Preservation Act National Marine Fisheries Service National Oceanic and Atmospheric Administration Notice of Intent National Pollutant Discharge Elimination System National Register of Historic Places Oregon Administrative Rules Oregon Coastal Management Plan Oregon Department of Fish and Wildlife Oregon Department of Transportation Ordinary High Water Ordinary High Water Mark Oregon Route Pacific Fisheries Management Council Pollution generating impervious surfaces Particulate Matter Personal Protective Equipment Protected Species Observer Resource Conservation and Recovery Act Response Boat – Small Rivers and Harbors Act River Mile Recreational Vehicle Search and Rescue Submerged Aquatic Vegetation Square Foot Oregon State Historic Preservation Office State Implementation Plan

June 2024 xv

SOP

SPCC

SPRP

SWPPP

TESC

TMDL

USACE

USC

USCG

USDOT

USGS

USFWS

V

WCRA

WOTUS

WQC

WQS

ZOI

Standard Operating Procedure Spill Prevention, Containment, and Countermeasure Spill Prevention and Response Plan Stormwater Pollution Prevention Plan Temporary Erosion and Sediment Control Total Maximum Daily Load United States Army Corps of Engineers United States Code United States Coast Guard United States Department of Transportation United States Geological Survey United States Fish and Wildlife Service Vertical Willamette Cultural Resources Associates Waters of the United States Water Quality Certificate Water Quality Standards Zone of Interaction

June 2024 1

1 PURPOSE AND NEED FOR ACTION

1.1 Introduction

The United States Coast Guard (USCG) is proposing to correct shoreline erosion and replace the covered mooring and appurtenant offshore structures at USCG Station Siuslaw River, Florence, Oregon (Station). To correct shoreline erosion, the USCG is proposing a durable, long-term solution through the installation of an interlocking steel pile wall along the length of the Station property waterfront. The replacement covered mooring will be a slightly larger structure constructed in the same general footprint and location as the existing covered mooring with a structure engineered to resist weathering and future riverbed deepening (scour).

1.2 Background

The Station was established at this site in 1917. Remodeled in the late 1980’s, the Station has facilities for administration and operations personnel, service buildings, berthing for on-duty personnel (Ready Crew), eight housing units, and limited parking situated on the sand bluff.

West of the Station, the sand bluff slopes steeply downward, approximately 40 feet to the Siuslaw River. An offshore covered mooring and floating debris boom provide covered berths for two 47-foot Motor Lifeboats (MLBs). The Station’s primary mission is Search and Rescue (SAR) operations for commercial mariners, recreational boaters, and water sports enthusiasts.

Other missions include escorting fishing vessels across the Siuslaw River bar, towing and marine salvage assistance, environmental protection and fisheries conservation enforcement, maritime law and treaty enforcement, and boating safety regulation enforcement.

The covered mooring is approximately 52 years old. Structural inspections of the covered mooring revealed that the foundation is severely overstressed, with significantly reduced pile embedment depths, and therefore threatened by riverbed scour (USCG 2013a). Shoreline erosion and riverbed scour also threaten access to and stability of the offshore facilities, and the potential for failure of the sand bluff threatens the stability of onshore infrastructure. Piles supporting the covered mooring’s access walkway failed in 2002 and had to be replaced. In 2008, the USCG installed supplementary piles to the covered mooring structure to provide extra lateral support and improve stability during periods of high winds and faster river currents. In addition, the Station's fuel tank was relocated due to hillside erosion and a resulting loss of land at the top of the sand bluff.

Since at least 1961, the Station has experienced both severe erosion of the shoreline and loss of river bottom material. There are several sources of erosion at this location. River currents, tidal flows, and wave energy result in a high-energy environment along the project area shoreline. The shoreline will continue to erode the sedimentary bedrock bluff toe laterally at an approximate rate of 1 to 2 feet per year. The eroding shoreline undermines the slope leading to periodic sloughing. The vertical face of the bedrock is visible at the toe of the sand bluff beyond the

June 2024 2 riprap extents, and as erosion continues, the possibility of a rotational failure of the hillside increases (Figure 1-1).

Figure 1-1. View E-SE along sand bluff shoreline from Station’s exterior floating dock

Stormwater overland flow contributes to surficial erosion in areas lacking sufficient vegetative cover. Investigations into the mechanics of the bluff failure indicated that surface water and precipitation have infiltrated into the younger, unconsolidated upper dune sands and then have abruptly traveled laterally when they reach the marine terrace deposit, or Paleosol layer (GeoScience 2011). This groundwater flow has been observed in several locations at or near the elevation of the Paleosol layer. Surficial observations of sinkholes, as determined by a geotechnical engineer, are likely due to the loss of subsurface dune sands (Shannon & Wilson, Inc. 2018).

The USCG implemented a bank stabilization project in 2016 (NWP-1997-1481/2) that resulted in placement of a riprap revetment along 220 feet of its shoreline both above and below Mean Higher High Water (MHHW). The revetment project has temporarily slowed the rate of erosion, but a permanent solution that addresses groundwater flow, erosive forces associated with tidal influence, and scour of the riverbed is needed to mitigate the long-term effects and enable the

Parking area slope failure

Vertical bedrock face

June 2024 3

USCG to maintain operations while preventing future erosion and scouring of the sand bluff and shoreline along the property.

The USCG completed an Environmental Feasibility Study (EFS) in 2018 (USCG 2018a). The EFS summarized the potential environmental impacts, identified the key permits and required reviews, listed stakeholders, and discussed potential mitigation options for several alternatives to correct shoreline erosion and replace the covered mooring. The purpose of the EFS was to assist the USCG in evaluating the feasibility of the alternatives and identifying a preferred alternative.

The elements for the preferred shoreline erosion correction and covered mooring replacement alternatives are described in detail in Section 2.1.2.

1.3 Study Area Description

The Station is seated atop a sand bluff on the east river bank at river mile (RM) 1.5 of the Siuslaw River approximately three miles northwest of the downtown waterfront of the City of Florence, Lane County, Oregon (Figure 1-1). Vegetated dunes in the Oregon Dunes National Recreation Area, protected by a series of four rock groin structures, are located on the bank of the Siuslaw River opposite of the Station. This study is focused on the Station property, including onshore and offshore areas, and the temporary mooring area that is proposed for use during construction (Figure 1-2). The onshore components of the Station are found approximately 75 feet above the mean tidal elevation of the Siuslaw River.

June 2024 4

Figure 1-2. Project Vicinity

June 2024 5

Figure 1-3. Site Map

June 2024 6

1.4 Purpose and Need for Action

The purpose of the USCG’s proposed activities is to create a permanent solution to ongoing streambank erosion, replace structures that have become hazardous, and update infrastructure to accommodate new equipment that is needed at the Station.

The project is needed to ensure the Station can fully and safely meet its mission. On-shore and in-water assets must enable the Station, which is designated as a Heavy Weather and Surf station, to maintain its Bravo-Zero response standard, which is the ability to respond within 30 minutes of an SAR alert. The two surf-ready MLB vessels at the Station could not be moored if the Station falls into disrepair. For instance, a potential loss of the covered mooring would require USCG to permanently lease moorings elsewhere upriver, which would significantly increase response time and negatively affect USCG mission efficiencies.

Continued sand bluff erosion, both from river dynamics and from the lateral subsurface movement of water will jeopardize more station infrastructure at the bluff onshore edge and adjacent upland facilities. The project would preserve waterfront operations at the Station by implementing a long-term solution to stabilize the hillside, thereby protecting the sand bluff and Station infrastructure from further erosion. In addition, the covered moorings, built in 1970, are beyond their serviceable life, and the foundation and pile supports have been compromised by river bottom scour, which directly impacts the structural stability of the covered mooring. By replacing the current foundation and supports, the project would help to ensure mission readiness and public safety.

1.5 Agency and Public Involvement

Public Scoping

On July 2, 2022, the USCG issued a Notice of Intent (NOI) to prepare an EA in The Siuslaw News, which serves Florence and the surrounding area. The USCG also directly notified stakeholders, including federal, state, and local government agencies, tribal organizations, and regulatory bodies, via electronic correspondence of its intent to prepare an EA. The NOI briefly described the Proposed Action, provided a schedule of public involvement opportunities, and requested input on the scope of the proposed project.

Release of the NOI started the 30-day scoping period, during which time the public could comment on the issues they felt needed to be addressed in the NEPA evaluation. Comments were received from five sources, including one county agency, one local homeowners’ association, and three federal government agencies. Most of the comments were written by the leader of a group or organization on behalf of its individual members. Nearly all commenters requested the USCG maintain open lines of communication with applicable regulatory agencies and interested stakeholders throughout the development of the EA. The comments are summarized in the Public Comment Summary found in Appendix A. The government agencies that provided scoping comments were:

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• Lane County

• National Oceanic and Atmospheric Administration, National Marine Fisheries Service

• United States Environmental Protection Agency

• Bonneville Power Administration USCG notified the Confederated Tribes of Coos, Lower Umpqua, and Siuslaw Indians and the Confederated Tribes of Siletz Indians of Oregon of the intent to develop an EA and welcomed input from the tribes. The USCG did not receive responses from any tribal representatives during the 30-day scoping period.

Public Review

The Draft EA was circulated for a 30-day public comment period running from March 6 to April 5, 2024 following publication of a notice of availability in the Siuslaw News. Comment letters or emails were received from five members of the surrounding community who expressed concerns about the proposed action’s potential impacts on their properties. Comments were also received from U.S. EPA Region 10. The Bonneville Power Administration submitted an email saying that they had no comments. All comments and the USCG’s responses are listed in Appendix A.

Agency Coordination

The USCG has performed extensive coordination with regulatory agencies and Tribes, during both the initial project planning phase (2018) and the current environmental documentation phase. On May 9, 2018, the USCG Facilities Design and Construction Center (FD&CC) held a meeting with staff from regulatory agencies, local governments, and interested tribes to describe the proposed project and solicit their comments regarding permitting, mitigation, and cultural resources compliance. The meeting was held at USCG Station Siuslaw River and was attended by representatives from eight agencies and tribes, as well as four USCG staff. Meeting materials, including a summary of the project setting and the project drawings, were provided to them at least one week prior to the meeting. A summary of this meeting is provided in Appendix A.

On May 18, 2022, the USCG held a pre-application meeting with staff from the regulatory agencies that are likely to issue permits, authorizations, or review of documents for this project.

The meeting was led by staff from the Oregon Department of Environmental Quality (DEQ).

Agencies with staff in attendance included the following:

• U.S. Army Corps of Engineers, Portland District

• U.S. Environmental Protection Agency, Region 10

• NOAA National Marine Fisheries Service

• DEQ

• Oregon Department of Fish and Wildlife (ODFW)

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• Oregon Department of Land Conservation and Development (DLCD)

• Oregon Department of State Lands (DSL)

Cultural Resources Coordination

The USCG prepared a cultural resources inventory report and submitted it, along with application materials, to the State Historic Preservation Officer (SHPO) on November 17, 2023.

Prior to initiating coordination with the SHPO, the USCG initiated consultation with the Confederated Tribes of Coos, Lower Umpqua, and Siuslaw Indians, the Confederated Tribes of Siletz Indians of Oregon, and the Coquille Indian Tribe. No responses were received from the tribes other than a request to add a list of authors to the cultural resources assessment report.

Copies of the consultation letters are provided in Appendix B.

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2 PROPOSED ACTION AND ALTERNATIVES

2.1 Alternatives for Evaluation

2.1.1 No Action Alternative

Under the No Action Alternative, measures to implement a long-term, engineered solution to correct shoreline erosion and replace covered moorings at the Station would not occur. Shoreline erosion caused by natural and dynamic riverine processes, increased impervious surfaces in the watershed, and associated stormwater discharges and groundwater flows would continue unchecked. The potential for a failure of the sand bluff threatening onshore facilities, river access, and potentially personnel safety would continue to increase. Stability of the covered structure would continue to diminish. Loss of the covered mooring would interrupt the Station’s ability to maintain a response boat and would require leasing moorings upriver, increasing USCG response time. Ultimately, the No Action Alternative would not meet the purpose and need and would diminish the USCG’s ability to successfully fulfill its mission in D13.

2.1.2 Preferred Alternative

The Preferred Alternative was selected because it will minimize environmental impacts from construction while satisfying the purpose and need for the action. The Preferred Alternative includes onshore stormwater infrastructure improvements, shoreline stabilization through the installation of a steel interlocking pile wall where the top of the wall is near to the 50-year extreme tide elevation to minimize fill below it, and offshore infrastructure demolition and replacement in the same area, but larger footprint, as the existing offshore infrastructure. These activities are described in greater detail below.

2.1.2.1 Project Footprint

The project footprint, or the limits of direct construction-related ground disturbance, will include onshore and offshore areas of disturbance within the project area depicted in Figure 1-3. Onshore disturbance (i.e., disturbance above the Highest Measured Tide (HMT)) will include stabilization of the upper slope with native vegetation to control surficial erosion, site access preparation, temporary staging, installation of new marine fuels piping and equipment between the upland storage tanks and covered mooring access, installation of a retaining wall near the top of the slope, installation of surface swales with gravel trench drains to divert surface water, and lower access road improvements. Offshore disturbance (i.e., disturbance below the HMT), will include demolition and removal of existing timber and steel H-piles and the covered mooring superstructure, a covered mooring access bridge, and a fixed debris boom. New structures will include installation of up to 79 new or replacement steel piles supporting the new covered mooring, covered mooring access bridge, and a fixed debris boom. The project footprint will also include the minor modification and use of a temporary mooring area and ready crew berth at the Port of Siuslaw, which will be used throughout the duration of construction.

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2.1.2.2 Onshore Infrastructure Improvements and Sitework

The asphalt drive used by USCG vehicles accessing the lower portion of the Station and covered mooring access bridge will be disturbed with pavement saw cuts to construct new modern marine fuel delivery piping that is to be buried between the upland diesel and gasoline storage tanks and the landward end of the covered mooring access bridge. Asphalt cement surfaces will be restored, and electrical modifications will be made, as required.

A new storm drain system consisting of surface swales with gravel trench drains underneath, storm piping, and filtration catch basins will be constructed to mitigate and protect upland facilities and sand bluff from erosion caused by stormwater surface runoff. The concept for a new storm drainage system is to collect and convey the majority of the upstream and site stormwater within a series of catch basins and storm pipe to a single outfall along existing riprap at the shoreline. Low Impact Development (LID) principles, or site planning to minimize impervious surfaces and stormwater runoff, will be employed to the extent practicable. LID best management practices (BMPs) will be required. BMPs included in final designs may include but would not be limited to bioretention and raingardens with engineered soils and a subsurface drain to emphasize filtration, storage, and evaporation and transpiration before runoff is conveyed to an outfall. Thus, the project will likely result in a slight net decrease in onshore impervious surfaces once these facilities are designed. No increase in onshore impervious areas is anticipated.

Existing catch basins will be removed and replaced with a water quality filtration unit(s) to treat runoff from impervious surfaces considered to be a significant source of pollutants in stormwater runoff, or pollution generating impervious surfaces (PGIS), before being conveyed and discharged from an outfall at the riprap layer. Filtration units specifically designed to capture specific pollutants such as zinc, copper, and sediments will be installed. A grassy swale underlain by a gravel trench will be installed along the top of the steep slope to collect lawn area surface sheet flows and shallow subsurface flows and convey them either offsite or to the outfall onsite. Additional trench drains will be installed along the pier access driveway after saw cutting and removing sections of the access drive pavement to prevent stormwater discharge onto the steep slope. Additional filtration units will be incorporated into the trench drains or catch basins used to capture the flow before the flow is conveyed to the outfall. The pier access drive will be repaved. Storm outfalls may pass through the wall proposed for shoreline stabilization and continue down the slope to discharge near the toe of the sand bluff slope at the upper elevation of the riprap to prevent shoreline erosion from the discharge.

2.1.2.3 Shoreline Stabilization

The USCG’s preferred alternative for shoreline stabilization is a steel interlocking pile wall, with the above-grade portion of the wall above the 50-year calculated extreme tide level (Figure 2-1).

The wall will run approximately 400 feet along the Siuslaw River from approximately the north property line to the south property line, with approximately 30 foot returns inland and upslope at either end. The wall will implement a long-term solution by adding a rigid structure of either

June 2024 11 steel pipe or steel sheet piles, with grouted soil tie-back anchors located near the top of the wall, that would retain upper and lower slope sands and mitigate negative scour effects on the soils landward of the wall. A drainage element (i.e., weep hole) at the elevation where the paleosol layer contacts the upper dune sands will facilitate a free draining retention system (e.g., nonwoven geotextile or an open-graded aggregate filter) to relieve groundwater flow and prevent loss of dune sand material.

Figure 2-1. Preliminary design of typical section for an interlocking wall

Installation will require a combination of auger predrilling and vibratory installation. The wall is planned to be installed just upslope of the existing riprap installed in 2016, which will be disturbed as little as possible. However, it is possible that some existing riprap located at or above the 50-year extreme tide elevation may have to be temporarily removed and stockpiled during construction if the riprap extents conflict with the footprint of the pile wall. Under current slope conditions, a small upper section of the waterward side of the wall would be visible throughout normal tidal fluctuations. It should be noted that scour forces in the river at this location are significant and have changed the depth of the riverbed to a great extent in this location over the last sixty years. It is possible that future scour will remove more bank material and remove or relocate the riprap and leave a more significant wall height exposed on the river side. The wall will be structurally designed for this potential future retained height.

Upslope of the proposed pile wall, protection against seepage-induced erosion and washout of lower sands will be provided to prevent undermining and erosion of the silt layer. The sand slope above the wall will be graded to maximum slope of 2H:1V and stabilized and protected through application of a geocell cellular confinement geotextile, nonwoven geotextile filtration system with granular stone embankment material and biotic soil media and planted with native vegetation or a combination thereof. Several surface swales with gravel trench drains will be added to divert surface runoff from sheet-flowing down the embankment and channeling them to

June 2024 12 the existing underground storm drain system. The existing outfall at the downstream end of the stormwater system will be enhanced to reduce further erosion by either expanding the flow spreader at the outfall or extending the pipe to be placed at-grade with cutoff concrete collars and outfalling beyond the new wall.

A second, smaller wall is proposed near the crest of the slope at the edge of the parking lot in the southwest corner of the property. This wall will be a cantilevered design, with the pile embedment taking into consideration the regraded slope of 2H:1V.

2.1.2.4 Offshore Infrastructure Demolition and Replacement

The Station’s covered mooring, access bridge and debris boom will be demolished, and all piles will be removed. The piles to be removed include:

• The original timber vertical piles and timber batter piles installed in 1969 and steel H-piles installed in 2008 that support the…