Permit 1. Final JPA_USCG Station Siuslaw_revised.pdf

1 April 2023

DATE STAMP

Joint Permit Application This is a joint application, and must be sent to all agencies (Corps, DSL, and DEQ). Alternative forms of permit applications may be acceptable; contact the Corps and DSL for more information.

U.S. Army Corps of Engineers Portland District

Oregon Department of State Lands

Oregon Department of Environmental Quality

Action ID Number Number

(1) TYPE OF PERMIT(S) IF KNOWN (check all that apply)

Corps: Individual Nationwide No.: _______ Regional General Permit_______ Other (specify)__________

DSL: Individual GP Trans GP Min Wet GP Maint Dredge GP Ocean Energy No Permit Waiver

(2) APPLICANT AND LANDOWNER CONTACT INFORMATION

Applicant Property Owner (if different)

Authorized Agent (if applicable)

Consultant Contractor

Name (Required) Business Name Mailing Address

Business Phone Cell Phone Fax Email

Capt. Neal E. Armstrong

USCG FDCC

915 2nd Avenue, Room 2664 Seattle, WA 98174 571-608-9243 845-659-1066

Neal.E.Armstrong@uscg.mil

Eric Campbell Campbell Environmental, LLC 28948 SW Meadows Loop Wilsonville, OR 97070 503-680-8390 503-680-8390 eric@campbellenviro.com

(3) PROJECT INFORMATION

A. Provide the project location

Project Name Latitude & Longitude (decimal)

USCG Station Siuslaw River: Covered Moorage and Shoreline 44.00221 N / -124.12225 W (WGS84)

Project Address / Location City (nearest) County

4255 Coast Guard Rd. Florence Lane

Township Range Section Quarter/Quarter Tax Lot(s)

18S 12W 15 1812153300600

Brief Directions to the Site

On US-101 head north of downtown Florence and turn left on 35th St; turn right on Rhododendron Dr (5286);

turn left onto Coast Guard Rd and arrive at the project site.

B. What types of waterbodies or wetlands are present in your project area? (Check all that apply.)

River / Stream Non-Tidal Wetland Lake / Reservoir / Pond

Estuary or Tidal Wetland Other Pacific Ocean

Waterbody or Wetland Name River Mile 6th Field HUC Name 6th Field HUC (12 digits) Siuslaw River ~1.5 Bernhardt Creek 171002060804

C. Indicate the project category. (check all that apply.)

Commercial Development Industrial Development Residential Development

Institutional Development Agricultural Recreational

Transportation Restoration Bank Stabilization

Dredging Utility lines Survey or Sampling

In- or Over-Water Structure Maintenance Other:

mailto:Neal.E.Armstrong@uscg.mil mailto:eric@campbellenviro.com http://tools.oregonexplorer.info/oe_map_viewer/viewer.html?Viewer=OE http://tools.oregonexplorer.info/oe_map_viewer/viewer.html?Viewer=OE

2 April 2023

(4) PROJECT DESCRIPTION

A. Summarize the overall project, including work in areas both in and outside of waters or wetlands.

The United States Coast Guard (USCG) is proposing to replace a boathouse, pier access bridge, and debris screen, and correct shoreline erosion at the United States Coast Guard (USCG) Station Siuslaw River (Station) in Florence, Oregon (see Attachment A: Figures and Attachment B: Plan Sheets). 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/boathouse, will be constructed in the same location as the existing covered mooring but with a larger footprint, and a structure engineered to withstand the elements and future riverbed scour (deepening). The proposed action will include in-water and over-water work, including vibratory and percussion pile driving. Upland improvements will include installation of a pile wall near the top of the bank slope, installation of surface swales with gravel trench drains to capture and divert surface water, and grading of the upland bank.

The project area is located on the river right (east) bank of the Siuslaw River at River Mile (RM) 1.5 approximately three miles northwest of the downtown portion of the City of Florence, Oregon. The project area is focused on the Station property including onshore and offshore areas.

Offshore (In-water/Over-water) Demolition and Replacement

The Station’s existing covered mooring, bridge, and debris screen will be demolished, and all piles will be removed. Piles supporting the boathouse to be removed include the original timber vertical piles and timber batter piles installed in 1969, and steel H-piles installed in 2008. Demolition debris and materials will be transported to a permitted landfill and/or recycling facility. In total, approximately 71 piles will be removed by vibratory hammer. A conservative estimate for vibratory extraction is 15 minutes per pile. If any timber piles break during removal, the remaining portion of the broken piles will be cut two feet below the mud line.

Removed piles will be disposed of in an upland location.

The following new facilities will be constructed: a 4,730 square foot (SF), two-bay covered mooring, including an interior floating dock for two 47-foot motor life boats (MLBs), a mezzanine and deck space for engineering shop and storage; a 1,220 SF pedestrian bridge, including a small marine diesel fueling platform; and a vertical debris screen. Total over-water structures will cover approximately 6,500 SF. It is estimated that up to 79 replacement steel piles will be necessary to reconstruct the boathouse, floating docks, bridge, and debris screen. The new piles will be 16-inch to 20-inch steel pipe piles filled with concrete, and/or 14-inch steel H-piles which will be installed by vibratory driving and driven to the final tip elevation by impact strikes after the initial vibratory set. The exact sizes and quantities of pipe piles used will be determined through the remaining design iterations. The new pier access and debris screen will be constructed in approximately the same footprint as the existing structures to minimize riverbed soil disturbance and shadowing from over-water structures. The new covered mooring footprint will be approximately 1,800 SF larger than the existing structure. The southeast corner will be placed in the same location but the west end of the structure will extend 30 ft further out into the Siuslaw River to accommodate the two 47-foot MLB’s. The existing covered mooring width is insufficient for mooring the two 47-foot MLBs. This will result in additional shadowing compared to existing conditions.

To mitigate for the additional pilings (approximately eight), and expansion of the covered mooring and dock (approximately 1,800 square feet) and debris screens (approximately 22 square feet); the USCG is proposing to purchase 2,000 square feet of estuarine credits from the Wilbur Island Mitigation Bank, and is currently coordinating with the Oregon Department of State lands on the credit approval and purchase. Estuarine wetlands have historically been degraded and lost in the Siuslaw watershed.

Upland Shoreline Stabilization

Shoreline stabilization will be accomplished through construction of an upland, steel interlocking pile wall, with the top of the above-grade portion of the wall above the 50-year calculated extreme tide level. The wall will run approximately 400 feet along the top of bank 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 consisting of steel sheet or pipe piles, with grouted soil tie-back anchors

3 April 2023 located near the top of the wall, that would retain the slope sands, and mitigate negative scour effects on the soils landward of the wall. A drainage element (e.g., weep hole) through the wall at the elevation of the Paleosol contact with the Upper Dune Sand will allow the free draining retention system, such as a nonwoven geotextile or an open-graded aggregate filter, to relieve groundwater flow and prevent piping (loss) of dune sand material.

Sheet or pipe pile installation would be a combination of auger predrilling and/or hydraulic press-in installation, as opposed to driven or vibratory installation approaches, which were determined to be less desirable as primary methods of installation, considering the hardness of the Lower Dune Sand layer and the potential for negative impacts to the marginally unstable slope. The wall is planned to be installed above highest measured tide (HMT), just upslope of the existing riprap installed in 2016, which will be disturbed as little as possible. 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 entirely 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, biotic soil media 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 the existing underground storm drain system. The existing outfall at the downstream end of the stormwater system will be extended with a pipe that will be placed at-grade with cutoff concrete collars and outfall beyond the new wall.

A second, smaller wall is proposed near the crest of the slope at the edge of the existing 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.

Upland Stormwater Improvements and Sitework

The existing, upland storm drain system consists of storm drain pipes and structures, and a below-surface horizontal drain array that collects at a triangular soil nail wall catchment area. The collected stormwater and groundwater are combined to discharge near the top of the slope through a controlled outfall protected with riprap.

Stormwater improvements will include minor modifications including some Low Impact Development (LID) storm system features that will reduce erosion and sedimentation loss at the project site. No additional impervious surface area will be added as part of the project. The concept is to adjust the existing storm drainage system and convey the stormwater to a single outfall and discharge beyond the new sheet pile wall onto an energy dissipater. Existing drainage structures will be retrofitted with manufactured treatments such as filter inserts for water quality treatment and LID best management practices (BMPs) will be incorporated where feasible to meet the City of Florence stormwater design standards. BMPs included in final designs may include, but would not be limited to, bioswales with engineered soils/gravel and a subsurface drain to emphasize filtration, storage, and evaporation and transpiration before runoff is conveyed to the outfall. The project will likely result in a slight, net decrease in existing impervious surfaces. The project will include the following onshore stormwater infrastructure improvements:

Addition of drainage swales with gravel trench drains to redirect runoff from the embankment and to slow down the surface flow and collect groundwater flow. The stormwater in the swale will discharge into the triangular soil nail wall catchment area prior to outfalling through a controlled outlet structure.

Addition of a trench drain to collect stormwater runoff currently flowing down the pier access driveway and over the embankment. The trench drain will redirect the runoff into a drainage structure which will release runoff at a controlled rate and prevent stormwater discharge onto the steep slope.

Retrofit or replacement of existing catch basins with water quality filtration unit(s) to treat runoff from impervious surfaces considered to be a significant source of pollutants in stormwater runoff, or pollution

4 April 2023 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.

Reconstruction of drainage outlet structure including water quality filtration inserts.

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 to the outfall onsite.

A surface-mounted storm outfall pipe anchored to the embankment slope will replace the existing outfall. The new outfall will discharge beyond the new sheet pile wall to an energy dissipater to prevent embankment erosion at the upper elevation.

Minor asphalt pavement repairs in the parking lot where the embankment failure occurred.

Shoreline stabilization including pile walls, a retaining wall and embankment reestablishment with native vegetation as described in the following section.

B. Describe work within waters and wetlands

Work within waters, (i.e., below the highest measured tide [HMT] of the Siuslaw River) will include piling removal and installation during the demolition and construction of the covered mooring, pier access bridge, and fixed debris screen. Approximately 71 existing pilings will be removed by vibratory hammer. They will be replaced by up to 79 steel piles installed below the HMT elevation. The USCG is proposing an in-water work window during the Oregon Department of Fish and Wildlife (ODFW)-preferred in-water work window from November 1 to February 15. No dredging is proposed for the project.

Over-water construction actions, or those which will be performed waterward of HMT line but above HMT line elevation, may be performed outside of the in-water work window subject to contractor means and methods.

This includes the construction of the new covered mooring, covered mooring access bridge, and fixed debris screen once the steel pipe piles have been installed.

A summary of proposed impacts below the HMT of the Siuslaw River is provided in Table 1 below. The proposed project will not impact wetlands.

Table 1. Summary of Permanent and Temporary Impacts to Waters and/or Wetlands.

Removal Volumes and Dimensions (if more than 7 impact sites, include a summary table as an attachment)

Wetland / Waterbody Name *

Removal Dimensions Time Removal is to Remain **

Material***

Length

(ft.)

Width

(ft.)

Depth

(ft.)

Area

(sq. ft.)

Volume

(c. y.)

Siuslaw River

Removal of 71 existing pilings (12” to 18” dia.)

81 1-2 ~50 74 137 Permanent Wood and steel pilings

Removal of existing dock floats

54.8 19.5 2.5 599 43 Permanent Concrete & Timber

Removal of existing debris screen

161.5 0.3 8.5 48 15 Permanent Steel

Removal of existing boathouse screen

152 0.6 15 91 50 Permanent Steel

Total Removal Volumes and Dimensions

Length (ft) Area (sq. ft.) Volume (c.y.)

Total Removal to Wetlands N/A N/A N/A Total Removal Below Ordinary High Water N/A N/A N/A

Total Removal Below Highest Measured Tide 449 738 245

Total Removal Below Mean High Water Tidal Elevation 449 738 171

Fill Volumes and Dimensions (if more than 7 impact sites, include a summary table as an attachment)

Wetland / Waterbody Name *

Fill Dimensions Time Fill is to

Remain ** Material*** Length

(ft.)

Width

(ft.)

Depth

(ft.)

Area

(sq. ft.)

Volume

(c. y.)

Siuslaw River http://www.oregon.gov/dsl/PERMITS/Pages/when_is_permit_reguired.aspx http://www.nwp.usace.army.mil/Missions/Regulatory/Jurisdiction.aspx

5 April 2023

Installation of up to 79 pilings (16” to 20” dia.)

122 1.3-1.6 ~50 148 274 Permanent Steel pilings

Installation of new dock floats

70.5 31.7 2.5 1010 75 Permanent Concrete & Timber

Installation of new debris screen

193 0.3 15 58 32 Permanent Composite & Steel

Installation of new boathouse screen

171 0.6 15 103 57 Permanent Composite & Steel

Temporary spud piles 2.6 1.3 ~30 3 3 Temporary Round steel

I. Total Fill Volumes and Dimensions

Length (ft) Area (sq. ft.) Volume (c. y.)

Total Fill to Wetlands N/A N/A N/A Total Fill Below Ordinary High Water N/A N/A N/A

Total Permanent Fill Below Highest Measured Tide 556.5 1,319 438

Total Perm. Fill Below Mean High Water Tidal Elevation 556.5 1.319 307

* If there is no official name for the wetland or waterway, create a unique name (such as “Wetland 1” or “Tributary A”).

** Indicate whether the proposed area of removal or fill is permanent or, if you are proposing temporary impacts, specify the days, months or years the fill or removal is to remain.

*** Example: soil, gravel, wood, concrete, pilings, rock etc.)

C. Construction Methods. Describe how the removal and/or fill activities will be accomplished to minimize impacts to waters and wetlands.

Piling removal is expected to be accomplished with a vibratory pile driver/extractor mounted to a crawler crane operated from an appropriately-sized spud barge. Removed piles will be staged on a second demolition debris barge for transportation. All pier pilings and timbers to be demolished are either steel, wood creosote, or salt treated. The contractor will be required to ensure that these timbers are handled and disposed of in accordance with applicable local, state, and federal regulations. The contractor will also be required to perform all required sampling and analysis and provide any required shipping and disposal paperwork. In addition, if any unidentified or unexpected hazardous materials are discovered during demolition work, the contractor will be required to immediately notify the USCG prior to commencing any further cleanup of the discovered materials.

Construction of the offshore infrastructure would be accomplished from a barge, or multiple barges, using similar equipment as described above for installation of the pile wall. It is assumed that up to three piles will be driven each 8-hour workday. The actual driving time for each pile could be as much as approximately one hour, but is anticipated to be less. Thus, an estimated 29 total days of pile driving (not all consecutive) will occur over the duration of the project. A full pile driving analysis will be completed to further refine and guide pile installation and the appropriate BMPs for pile installation. Smaller work vessels and platforms will be utilized to construct the covered mooring superstructure.

It is anticipated that the installation of the upland pile wall would be from a barge or similar floating work platform which would also serve as the primary staging area. Typical equipment for this work would include a drill or hydraulic rig (or both), an appropriately-sized crawler crane or tracked hydraulic excavator (or both) for mounting and operation of the drill, or hydraulic rigs operated from a spud barge, and a support and materials barge. A small support boat and barge tug would be required periodically for positioning equipment or materials. To facilitate construction of the pile wall a bench will be needed on the upper slope (above HMT) for access, or another similar means, to construct the wall and install the tie-backs. The upper slope will be fully restored including invasive removal and native revegetation with a contractor-required establishment and maintenance period.

Upland site and stormwater infrastructure work will require a staging area designated within the Station’s property for heavy equipment and materials. A temporary stockpile area or areas will also be designated.

Temporary erosion and sediment control BMPs, including outlet protection, inlet protection, biofilter bags, stabilized construction entrances, sediment fencing, and straw wattles, as appropriate for site conditions, will http://www.oregon.gov/dsl/PERMITS/Pages/when_is_permit_reguired.aspx http://www.nwp.usace.army.mil/Missions/Regulatory/Jurisdiction.aspx

6 April 2023 be installed prior to ground disturbance. Typical equipment for this work would include one or more appropriately-sized tracked hydraulic excavators, wheel loader, track loader, on-road dump truck(s), water pumps, pavement sawing equipment, compacting equipment, paving machinery, and common landscaping equipment. Excavated materials will either be stockpiled for reuse or removed from the site to a permitted landfill as per the final plans and specifications. Disturbed natural area grades and vegetation will be restored upon completion of stormwater infrastructure upgrades and sitework.

Exact equipment requirements and construction means and methods will be determined through ongoing studies, surveys, and the design-build contractor’s design process using the final engineering designs, specifications, and estimates.

Measures to Minimize Impacts: Conservation measures will be implemented during construction to avoid or minimize potential adverse effects to protected species. Some measures, particularly those covering hazardous materials, may also apply to operations and/or maintenance of the proposed action.

General conservation measures for implementation during construction are worker environmental rules and regulations awareness training and construction best management practices (BMPs) to avoid or minimize construction activity effects on the sensitive site resources (habitats and species). Other specific measures are outlined below.

Water Quality

Placement of floating silt curtains or similar in-water turbidity barriers around the in-water work area to prevent migration of disturbed fine sediments away from the area of in-water work.

Best engineering and management practices will be employed to minimize water column discharges.

Implementation of a turbidity monitoring framework consistent with the Oregon Department of

Environmental Quality 401 water quality certification, permit terms and conditions, and ESA consultation conservation measures.

Implementation of a Stormwater Pollution Prevention Plan (SWPPP).

Implement a site-specific Temporary Erosion and Sediment Control (TESC) plan to minimize erosion and sedimentation with site appropriate BMPs.

Install and maintain appropriate TESC measures prior to disturbance to avoid and minimize effects to waterbodies, wetlands, and stormwater treatment facilities resulting from clearing, grading, and management of site drainage. This may include placement of silt fencing, wattles, dewatering sediment basin(s), or other protective barriers to ensure that soils are not introduced into waterways.

Revegetation and mulching of disturbed upland areas to minimize runoff of fines during precipitation events.

The construction contractor will limit the amount of soil disturbance to that which can be adequately controlled via constructible BMPs.

Construction entrances will contain either rock pads or tire wash facilities to prevent tracking of soil onto local roadways and to prevent the potential for sedimentation and turbidity of receiving waters as a result of runoff from roadways.

Stockpile areas will be contained and protected by erosion control measures such as silt fencing and straw bales. Stockpiles shall also be covered if inclement weather is forecast.

Appropriate stockpile and staging areas will be identified and approved prior to construction.

Noise and Vibration

Placement of bubble curtains, properly configured for the water velocity, around 100% of the piling perimeter and full water column when using impact hammers for piling installation.

A soft-start technique will be used during pile driving to allow fish (and marine mammals) to vacate the area before the pile driver reaches full power. For vibratory hammers, the contractor will initiate the driving for 15 seconds at reduced energy followed by a 1-minute waiting period. This procedure shall be repeated two

7 April 2023 additional times before continuous driving is started. For impact driving, an initial set of three strikes will be made by the hammer at 40 percent energy, followed by a 1-minute waiting period, then two subsequent three-strike sets before initiating continuous driving.

Noise and vibration mitigation through use of devices to muffle equipment, use of quieter equipment, and proper maintenance of marine vessels and equipment.

Hazardous Material

Implementation of a Spill Prevention, Containment, and Countermeasure (SPCC) plan. Maintain a current copy of approved SPCC plan on-site for the duration of the project and ensure that no work or staging occurs prior to implementing the plan. The approved plan provides site- and project-specific details identifying potential sources of pollutants, exposure pathways, spill response protocols, protocols for routine inspection fueling and maintenance of equipment, preventative and protective equipment and materials, and emergency notification and reporting protocols. Ensure that all workers understand the plan and response and reporting standards.

Absorbent materials will be employed if petrochemical sheen is observed and kept in place until sheen dissipates.

Clean and inspect all equipment to be used for the construction activities prior to arriving at the project site.

Ensure that no potentially hazardous materials are exposed, no leaks are present, and that equipment is properly functioning.

An in-water debris boom and oil adsorbent boom will be deployed around all active work areas and in-water equipment during construction and demolition to ensure containment of materials, wastes, debris, and/or contaminants. Care will be taken to prevent debris from entering the water during demolition and construction, and debris will be removed promptly if it does enter the water. Any contaminated wastes will be disposed of at a properly permitted disposal site.

Pile removal BMPs will be employed to prevent potential contaminant release into the environment and include vibratory extraction methods, keeping extraction equipment out of the water, and use of a containment basin on the barge where removed piles will be placed and temporarily stored.

Staging area and storage areas will be designated to store materials, fuel, and equipment. Equipment will be staged at least 150 feet from any natural water body or wetland to avoid contamination of water bodies or sediments.

Utilize BMPs for controlling pollution from ship mooring and fueling facilities during MLB operations.

Habitat Disturbance or Alteration

To control spread of non-native species, construction equipment will be washed before mobilization, and clean fill material will be required as necessary. The contractor will be required to inspect marine equipment.

Existing non-native or invasive species will be controlled as feasible without use of pesticides on the site to promote native vegetation growth and dominance.

Riparian vegetation will be preserved to the extent practicable while still allowing constructability.

Tree removals shall be mitigated per applicable local land use ordinances.

Disturbed soils shall be seeded with native species immediately as construction phasing allows.

Collision

All vessels will be restricted to 10 knots (~11.5 mph) speed over ground limit or less where required by the

City of Florence in the Siuslaw River estuary.

A monitoring zone of 500 feet will be maintained for all marine mammals.

8 April 2023

D. Describe source of fill material and disposal locations if known.

Fill materials will consist of up to 79 steel pilings. All removed wood and steel pilings (approximately 71 total) will be placed in a contained area and hauled to an appropriate upland location for disposal.

E. Construction timeline.

What is the estimated project start date? July 2024

What is the estimate project completion date? February 2026

Is any of the work underway or already complete? Yes No If yes, describe.

No construction work is complete. The Request for Proposal (RFP) designs and specifications for the design-build contractor and environmental studies are complete. Work will be phased and proposed/estimated dates are dependent on outcomes of ESA/MMPA consultations and ongoing permitting efforts.

(5) PROJECT PURPOSE AND NEED

Provide a statement of the purpose and need for the overall project.

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. Shoreline erosion will continue to laterally erode the sedimentary bedrock bluff toe 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, and as erosion continues, the possibility of a rotational failure of the hillside increases. The USCG implemented a bank stabilization project in 2016 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 the tidal riverine environment, and scour of the riverbed is needed to mitigate the long-term effects and enable the USCG to maintain operations while preventing future erosion and scouring of the sand bluff and shoreline along the property.

The covered mooring is approximately 51 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 2013). Shoreline erosion and riverbed scour also threatens 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 with high winds and river currents. In addition, the Station's fuel tank was relocated due to hillside erosion and resulting loss of land at the top of the sand bluff.

The purpose of the USCG Construct Covered Moorings and Correct Shoreline Erosion at Station Siuslaw River Project 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. Structural updates include replacement of the covered mooring with an interior floating dock for two 47’ MLBs, a pier access bridge, and a debris screen.

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, designated Heavy Weather and Surf, to maintain its Bravo-Zero response standard, or ability to be underway within 30 minutes of a SAR alert. This means maintaining the two surf-ready (MLB) vessels at the Station, which would be interrupted by the loss of the covered mooring. If use of the covered mooring at the Station was lost, the USCG would need to permanently lease moorings elsewhere upriver, which would significantly increase response times and decrease mission effectiveness. Continued sand bluff erosion, both from river dynamics and from the stormwater/groundwater lateral subsurface movement, will jeopardize more station infrastructure at the bluff onshore edge and adjacent upland facilities. The project

9 April 2023 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 the 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.

USCG. 2013. Waterfront Facilities Special Inspections. United States Coast Guard Station Siuslaw River Boat House (B003). Florence, Oregon. USCG Project No. PSN 4874939. Task Order No. HSCG88-13-J-PQQ013. January 2013. Prepared by: Appledore Marine Engineering, Inc.

(6) DESCRIPTION OF RESOURCES IN PROJECT AREA

A. Describe the existing physical and biological characteristics of each wetland or waterbody. Reference the wetland and waters delineation report if one is available. Include the list of items provided in the instructions.

According to a wetland delineation performed at the station, no vegetated wetlands occur in the project area.

Most of the historical wetland habitat in the project area has been modified or no longer exists. River conditions within the project area are generally not suitable for the establishment of submerged aquatic vegetation (SAV).

SAV in this area is limited by the high energy aquatic environment that has scoured away the riverbed, leaving behind mostly consolidated sands within the intertidal zone and the deepened subtidal zone. The depth of suitable soft-bottom substrates such as silt, mud, or fine sands limits SAV establishment within the project area. Although SAV, including fringe and flats eelgrasses (Zostera spp.), are present in the Siuslaw River estuary, none are known to occur within the project area.

The bank adjacent to the Siuslaw River throughout the project area is a steep slope approximately 45-50 feet in height. The lower portion of the slope up to just above the highest measured tide, or approximately +12.0 feet (NAVD88), is covered with riprap and armor rock. Thus, there is no overhanging riparian vegetation.

Above the riprap and armor rock, the slope is a mixture of upland and riparian vegetation, mostly shrubs with a few mature trees, with some scattered riprap underlying the slope’s sandy soils. Dominant species include Hooker willow (Salix hookeriana) on the lower slope influenced by the stormwater (and groundwater) drainage outfall towards the north end of the slope and Pacific wax myrtle (Myrica californica), salal (Gaultheria shallon), and evergreen huckleberry (Vaccinium ovatum). The few mature trees on the dune slope are Sitka spruce (Picea sitchensis) and shore pine (Pinus contorta var. contorta). Relatively abundant cover of non-native and invasive species including Scotch broom (Cytisus scoparius), gorse (Ulex europaeus), Himalayan blackberry (Rubus armeniacus), English ivy (Hedera helix), and reed canarygrass (Phalaris arundinacea) are also established on the slope.

Siuslaw River Estuary: The proposed project area in the lower estuary is located approximately 2 miles upstream of the Siuslaw River entrance at the Pacific Ocean. The lower estuary is characterized by high current velocities and wave action and is well within the tidal zone. The hydrology in the lower Siuslaw River is directly related to the rising and falling of tides (two high and two lows each day) and influence of river flows.

Tides may cause noticeable flow reversal and changes to water surface elevations. Winds drive the maximum wave heights observed at Station Siuslaw which generally range between two and three feet. Peak flows in the Siuslaw River coincide with the heaviest rainfall during winter storms commonly from December through January, and snow melt can add to runoff in the spring leading to a second (usually lower peak flow) freshet in early spring. The lowest mainstem river flows typically occur in August or September coinciding with the lower summer rainfall amounts (USGS station 14307620 Siuslaw River near Mapleton).

Water quality in the Siuslaw River has been degraded by decades of land and water-based development activity without sufficient applications of BMPs which have introduced contaminants from agricultural, forestry, urban, and industrial actions.The mainstem lower Siuslaw River (estuary), inclusive of the project area, is impaired and listed as a water quality limited surface water needing a Total Maximum Daily Load (TMDL;

Category 5: Section 303(d)-list) for temperature (year-round), fecal coliform, and sedimentation for fish and aquatic life and fishing beneficial uses. The mainstem lower Siuslaw is also 303(d) listed for Arsenic (Inorganic

– human health criteria) for fishing and private and public domestic water supply beneficial uses (ODEQ 2020).

No TMDLs have been established for the mainstem lower Siuslaw River assessment unit.

10 April 2023

Stormwater runoff from the site is conveyed through a system of collection structures and pipes that connects to a single outfall discharging into a vegetated area above the upper extent of the riprap and armor rock revetment before flowing into the Siuslaw River. Stormwater is collected from impervious surfaces within the Station including parking areas and driveways intended for vehicle use. No specific water quality concerns have been identified at the project location.

Estuarine habitat availability in the lower Siuslaw River has declined for more than a century as a result of land use and continual development. Adverse effects to estuarine habitat from these stressors include reductions in off-channel salmonid refugia habitat due to loss of tidal wetlands, extensive riprap bank armoring affecting intertidal and subtidal habitats, chemical contamination, sedimentation, and generally reduced primary productivity. Within the project area, the lower Siuslaw River generally lacks complexity and floodplain connectivity; areas of off-channel refugia and in-water habitat features for natural cover such as submerged logs or roots are limited due to extensive shoreline development and associated bank stabilization features as well as the high energy environment.

A video survey conducted in 2013 by ODFW within the project area determined at that time that the marine intertidal and subtidal habitats consisted of intertidal and subtidal sandstone terrace (rocky shelf) and undercut banks with woody roots from shoreline vegetation, a subtidal gravel/cobble/shell rubble flat, and a subtidal sandy shell bottom. Fish migrating through or residing within the area are known to occur year-round. Fish use includes anadromous fish like coho and chinook salmon and groundfish species like sculpins, lingcod, rockfish, flatfish, and kelp greenling. Mollusk species such as Dungeness crab, gaper clams, and piddock clams can also be found in the area.

ODEQ. 2020. Oregon’s 2018/2020 Section 303(d) List of Category 5 Water Quality Limited Waters Needing a TMDL. Approved by the

U.S. EPA on November 12, 2020. Available at: https://www.oregon.gov/deq/wq/Pages/epaApprovedIR.aspx. Accessed July 2022.

ESA-Listed Species: There are 13 Federal Endangered Species Act (ESA)-listed fish and wildlife species with the poential to occur within the vicinity of the project area. U.S. Fish and Wildlife (USFWS) listed species include Pacific marten, marbled murrelet, northern spotted owl, western snowy plover, leatherback sea turtle, loggerhead sea turtle, and Olive Ridley sea turtle. National Marine Fisheries Service (NMFS)-listed species include coho salmon, Pacific Eulachon, North American green sturgeon, humpback whale (Central America DPS and Mexico DPS), and the killer whale.

The lower Siuslaw River, including waters within the proposed project site, is designated as composite essential fish habitat (EFH) for all Pacific coast groundfish including arrowtooth flounder, starry flounder, any species of rockfish, lingcod, Pacific cod, Pacific Ocean perch, Pacific spiny dogfish, Pacific whitling, sablefish, shorspine thornyhead, dover sole, and petrale sole, as well as chinook and coho salmon species.

Coho salmon critical habitat can be found in the project area. Estuarine areas that are free of artifical obstruction and predation, natural cover, and meet water quality and salinity standards for juvenile and adult forage habitat occur in the project area.

Activities associated with the proposed project will occur over and below the HMT of the Siuslaw River, and have the potential to affect fish species listed as threatened or endangered under the ESA. The USCG has initiated consultation with NMFS through submittal of a Biological Assessment to facilitate compliance with Section 7(a)(2) of the ESA, as amended. The resulting Biological Opinion, once received, can be provided upon request. The proposed project will have no effect on ESA-listed species protected under the jurisdiction of

USFWS.

Marine Mammals: In addition to the ESA-listed species discussed above, there are three marine mammal species protected under the Marine Mammal Protection Act (MMPA) with the potential to occur within the vicinity of the project area, including harbor seals, California sea lions, and Stellar sea lions. Use of the area by seals and sea lions is frequently observed near the groin structures on the left bank of the river across from the Station and on abandoned docks near the temporary mooring location at the Port marina.

As such, the USCG has requested an incidental take authorization from NMFS under Section 101(a)(5) of the MMPA, as amended, through submittal of an Incidental Harassment Authorization (IHA) application. The

11 April 2023 application includes the potential effects of the project’s proposed activities on marine mammals and their habitat in the region, as well as mitigation measures and monitoring protocols to minimize those effects.

B. Describe the existing navigation, fishing and recreational use of the waterbody or wetland.

Navigability of the Siuslaw River is maintained by the U.S. Army Corps of Engineers (USACE) as a shallow draft estuary. The Federal Navigation Channel (FNC) in the Siuslaw River was authorized to decrease waiting times for vessels crossing the river bar and to provide a protected, dependable, year-round entrance for small draft tugs and barges, as well as commercial and recreational fishing vessels. The Cannery Hill reach of the Siuslaw FNC is located west of the existing offshore infrastructure and proposed project area. Periodic, infrequent maintenance dredging by the USACE maintains this channel.

Boaters and fishermen use the waters and shorelines of the Siuslaw River year-round, but boating and fishing in the immediate project area are not allowed for Station Siuslaw security reasons. No commercial fishing fleets currently port in Florence. The Port of Siuslaw offers recreational boat moorage, a boat launch, and a recreational vehicle campground with amenities at the Port of Siuslaw Campground and Marina located adjacent to the Siuslaw River in Old Town Florence.The South Jetty crab dock is less than one mile northwest from the project area on the Siuslaw River west bank and is open to the public year-round.

(7) PROJECT SPECIFIC CRITERIA AND ALTERNATIVES ANALYSIS

Describe project-specific criteria necessary to achieve the project purpose. Describe alternative sites and project designs that were considered to avoid or minimize impacts to the waterbody or wetland*.

The USCG prepared an Environmental Feasibility Study in 2018 which describes the alternative designs considered to minimize impacts in the Siuslaw estuary (see Attachment C: Alternatives Analysis). There are no alternative sites that could feasibly meet the purpose and need for the project. The USCG evaluated 12 alternative designs, including bank armoring and use of bioengineered materials to stabilize the bank, and determined that the proposed action would best meet the purpose and need for the project while minimizing potential impacts to regulated aquatic resources.

The bank stabilization and boathouse replacement features must be of sufficient strength and resiliency to withstand constant erosive and hydraulic forces typical of a high-energy, tidal environment. The highly erosive soils that comprise the bank offer minimal structural support, and will fail without the reinforcement offered by the proposed steel wall. The bed of the Siuslaw River continues to degrade, requiring installation of deeper piles to provide structural stability over a 50-year design life span.

12 April 2023

(8) ADDITIONAL INFORMATION

Are there any state or federally listed species on the project site? Yes No Unknown

Is the project site within designated or proposed critical habitat? Yes No Unknown

Is the project site within a national Wild and Scenic River? Yes No Unknown

Is the project site within a State Scenic Waterway? Yes No Unknown

Is the project site within the 100-year floodplain? Yes No Unknown

If yes to any above, explain in Block 6 and describe measures to minimize adverse effects to these resources in Block 7.

Is the project site within the Territorial Sea Plan (TSP) Area?

If yes, attach TSP review as a separate document for DSL.

Yes No Unknown

Is the project site within a designated Marine Reserve?

If yes, certain additional DSL restrictions will apply.

Yes No Unknown

Will the overall project involve ground disturbance of one acre or more?

Yes No Unknown

If yes, you may need a 1200-C permit from the Oregon Department of Environmental Quality (DEQ).

Is the fill or dredged material a carrier of contaminants from on-site or off-site spills?

Has the fill or dredged material been physically and/or chemically tested?

Yes No Unknown

Yes No Unknown

If yes, explain in Block 6 and provide references to any physical/chemical testing report(s).

Has a cultural resource (archaeological and/or built environment) survey been performed on the project area?

Yes No Unknown

Do you have any additional archaeological or built environment documentation, or correspondence from tribes or the State Historic Preservation Office?

Yes No Unknown

If yes, provide a copy of the survey and/or documentation of correspondence with this application to the Corps only. Do not describe any resources in this document. Do not provide the survey or documentation to DSL.

Is the project part of a DEQ Cleanup site? No Yes Permit number ______ DEQ contact._________

Will the project result in new impervious surfaces or the redevelopment of existing surfaces? Yes ☐ No ☒ If yes, the Applicant must submit a post-construction stormwater management plan as part of this application to DEQ’s 401 WQC program for review and approval, see https://www.oregon.gov/deq/FilterDocs/401wqcertPostCon.pdf

Identify any other federal agency that is funding, authorizing or implementing the project.

Agency Name Contact Name Phone Number Most Recent Date of Contact

List other certificates or approvals/denials required or received from other federal, state or local agencies for work described in this application.

Agency Certificate / approval / denial description Date Applied

NMFS

Oregon DEQ

DLCD

Biological Opinion 401 Water Quality Certification CMZ Consistency Determination

Other DSL and/or Corps Actions Associated with this Site (Check all that apply):

Work proposed on or over lands owned by or leased from the Corps (may require USC 408 authorization)

State Owned Waterway DSL Waterway Lease #

Other Corps or DSL Permits Corps # DSL #

Violation for Unauthorized Activity Corps # DSL #

Wetland and Waters Delineation Corps # DSL #

Submit the entire delineation report to the Corps; submit only the concurrence letter (if complete) and approved maps to DSL. If not previously submitted to DSL, send under a separate cover letter.

http://www.dfw.state.or.us/wildlife/diversity/species/threatened_endangered_candidate_list.asp http://www.fws.gov/oregonfwo/Species/Lists/ http://www.rivers.gov/rivers/oregon.php http://www.oregon.gov/dsl/WW/Pages/SSW.aspx http://msc.fema.gov/ http://www.oregon.gov/dsl/PERMITS/docs/TSP2_Checklist.pdf http://www.oregonocean.info/ http://www.deq.state.or.us/wq/stormwater/constappl.htm https://www.oregon.gov/deq/FilterDocs/401wqcertPostCon.pdf

13 April 2023

(9) IMPACTS, RESTORATION/REHABILITATION, COMPENSATORY MITIGATION

A. Describe unavoidable environmental impacts that are likely to result from the proposed project. Include permanent, temporary, and direct and indirect impacts.

Permanent/Direct Impacts: In-water work necessary to install piles supporting the new in-water structures will create noise disturbance and temporarily disturb aquatic habitat. This is reasonably expected to result in temporary behavioral displacement to nearby unaffected areas of aquatic species that are present in or in the vicinity of the active work area. Although displacement or change in behavior may occur, no fish or wildlife mortality is expected to occur. No other long-term effects are expected on marine and estuarine habitat.

Potential direct effects to federal ESA-listed fish species and their habitats include 1) effects of elevated in-water sound levels from in-water work, including pile driving, with the potential to injure or illicit behavioral responses from fish, 2) effects related to potential spills and leaks into the estuary from heavy construction equipment and marine construction vessels, 3) temporary effects of altered water quality from increased turbidity and suspended sediment concentrations in the water column due to disturbance of the aquatic bed from piling removal and installation, 4) effects from temporary reduction in available benthic prey, and 5) effects of temporary disruptions to free migration. Conservation measures will be implemented during construction and/or operations and maintenance of the project to avoid or minimize potential adverse effects to protected species and/or habitats.

The USCG will comply with the amount or extent of take and Terms and Conditions established by the project’s forthcoming Biological Opinion. Therefore, effects to federally threatened and endangered species and their prey are expected to be moderate and short term.