C05_06_-_Dredging_Plan_Speelyi_Amend_0002_0002.pdf

Dredging (Excavation) Plan

Cle Elum Dam Pool Raise Project:

Speelyi Shoreline Protection Project

Yakima River Basin Water Enhancement Project, Kittitas County, Washington Columbia-Pacific Northwest Region 9

U.S. Department of the Interior June 2026

Mission Statements The Department of the Interior conserves and manages the Nation’s natural resources and cultural heritage for the benefit and enjoyment of the American people, provides scientific and other information about natural resources and natural hazards to address societal challenges and create opportunities for the American people, and honors the Nation’s trust responsibilities or special commitments to American Indians, Alaska Natives, and affiliated island communities to help them prosper.

The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public.

Table of Contents

Table of Contents

Section 1 Dredging (Excavation) Plan

1.1 Introduction

Section 2 Project Location

2.1 Project Location

Section 3 Project Description

3.1 Project Introduction

3.2 Proposed Action

3.3 In Water Work below the Ordinary High Water Mark

3.4 Water Quality Protection

3.4.1 Best Management Practices

3.4.2 General BMPs for Construction Near Sensitive Areas:

3.4.3 Regulatory Controls:

Section 4 Specification Requirements

4.1 Dredging/Excavation

4.2 Storm Water Pollution Prevention Plan

Section 5 Permit Drawings

5.1 Drawings

Section 6 Monitoring and Record Keeping

6.1 Monitoring

6.2 Record Keeping

This page intentionally left blank

Speelyi Shoreline Protection Project 1

Section 1 Dredging (Excavation) Plan

1.1 Introduction

This Draft Dredging (Excavation) Plan is being provided by the U.S. Department of the Interior, Bureau of Reclamation (Reclamation) as part of the submittals to the Washington State Department of Ecology Request for Clean Water Act Section 401 Water Quality Certification. Construction work will be completed by a Construction Contractor who has not been identified at the time of preparation of this plan. Once a Contractor is selected, the Contractor will finalize this draft plan and be subject to the requirements herein as part of the Clean Water Act Section 401 Water Quality Certification Request.

Section 2 Project Location

2.1 Project Location

The project site is located near the Speelyi Day Use Area on Cle Elum Lake, about 8 miles northwest of the city of Cle Elum in Kittitas County (Figure 1). The approximate center of the project is 47.256 N lat. / -121.061 W long. The project will occur on both federal and private lands, with a majority of the work occurring on federal land, but also with a significant portion of work occurring on private parcel 291934 (Section 2, Township 20N, Range 14E).

Figure 1 Location of Speelyi Site location. Located approximately 8 miles northwest of Cle Elum, Washington.

Speelyi Shoreline Protection Project 2

Section 3 Project Description

3.1 Project Introduction

The Speelyi Shoreline Protection Project is a component of the larger Cle Elum Pool Raise (CEPR) Project, which is a component of the Yakima River Basin Integrated Water Resource Management Plan. The CEPR Project will raise the reservoir’s maximum pool elevation from 2240’ to 2243’ adding 14,600-acre-feet of additional storage which will be dedicated to enhancing instream flows for fish rearing, fish habitat and migration. Due to the 3-foot raise of the reservoir water surface elevation specific areas on the shoreline may be affected, Speelyi being one of those areas.

The Speelyi Shoreline Protection Project will provide mitigation for the 3-foot raise by armoring a section of shoreline with riprap at a 2:1 slope and creating a perched beach at the northern end of the project limits as shown in the drawings provided with the permitting application. Fill for the slopes will be borrowed within the limits of work shown on the drawings, mostly from the key trench required to hold the riprap in place. Additional fill, if required, will be borrowed within the project limits shown on the drawings only if the reservoir level is sufficiently low as to not require dredging.

3.2 Proposed Action

The Speelyi Shoreline Protection Project will stabilize an approximately half-mile long section of shoreline within the Cle Elum reservoir that may otherwise be adversely impacted by wave action from water during high water years as a result of the increase in pool level. Without mitigation, the shoreline would be at risk of erosion due to higher water levels as a result of the CEPR Project.

Riprap will be imported from an off-site source to protect the shoreline. The perched beach section of the project will be constructed with borrow material generated from excavating the riprap key trench and by importing riprap material. The United States Forest Service (USFS) will implement a revegetation plan post construction.

The project is expected to take three months on-site starting in Fall of 2026. All construction will occur when the pool water level is low and below the lowest elevation of the project footprint, and as such the construction start date is subject to pool elevation levels. Therefore, though the expected work window is between September and November 2026, the work may need to be postponed to the next favorable work window based on historic pool elevations, which is between March and early June 2027. Should contract timing not work out for completion of the work in one continuous period, there may be a period over the winter when work stops before resuming in the spring. These time windows are estimated and the Contractor will develop a proposed construction schedule at the start of construction.

All work will be performed in the dry when the water level in Cle Elum Reservoir is at elevation 2225 or lower. Most of the activities will be located within the reservoir boundaries, below the new OHWM defined in the CEPR project of elevation 2243. As such, project work is considered "in-water work", hence the need for this plan. Removal of material from the work area would be considered dredging if water were present. However, despite work being conducted below the OHWM, all work will occur “in the dry” when the reservoir elevation is no higher than elevation

Speelyi Shoreline Protection Project 3

2225, so any borrow material taken from the work area would fall under the definition of excavation for this project.

Construction will include excavation of a key trench to hold riprap in place, shaping the final slope of the embankment at a 2:1 slope for riprap placement, grading a perched beach area at the northern end of the project, and reshaping a slough channel on private property so that it properly drains to the reservoir rather than subjecting private parcel 291934 to flooding.

3.3 In Water Work below the Ordinary High Water Mark

No dewatering will be necessary for the Speelyi Shoreline Protection Project. Though construction is occurring below the ordinary high-water mark, the water surface elevation is expected to be at least 50 feet below the lower construction zone boundary during construction work. If, come the time of construction, the water surface elevation is higher than expected, then construction would be postponed until adequate conditions for construction are met, with no construction work occurring if the reservoir level rises to elevation 2220 or higher.

The following activities will occur in the Cle Elum Reservoir below the Ordinary High-Water Mark:

• Grading a portion of the shoreline slope and installing riprap for armoring.

• The majority of key trench excavation for riprap placement.

• Creating a perched beach at the northern end of the site using excess excavated material generated from the slope where riprap will be placed.

• Grading a temporary access road for construction vehicle access, which will be restored to its pre-construction state when no longer required for Contractor access.

• Grading the majority of the slough channel to ensure that reservoir storage water when at full pool has less of an impact on parcel 291934 and so that it routes stormwater around the structures on the parcel.

3.4 Water Quality Protection

The construction contractor will develop and implement a temporary erosion and sediment control (TESC) plan for all aspects of project construction requiring clearing, vegetation removal, grading, ditching, filling, embankment compaction, demolition, and/or excavation. BMPs defined in the plan will be used to control sediments from all vegetation removal or ground-disturbing activities. This plan will be required as a submittal in Reclamation’s construction contract, due a minimum of 28 days before starting work, and work will not be allowed to start until the plan is approved.

The construction contractor will develop a spill prevention control and countermeasures (SPCC) plan before beginning construction. The SPCC plan will identify the appropriate spill containment measures that will be used throughout project construction. This plan will be required as a submittal in Reclamation’s construction contract, due a minimum of 28 days before starting work, and work will not be allowed to start until the plan is approved.

Reclamation’s Construction Contractor will adhere to water quality standards as stated in the 401 Water Quality Certificate and National Pollution Discharge Elimination System (NPDES) permit issued for the project as applicable.

Speelyi Shoreline Protection Project 4

3.4.1 Best Management Practices

BMPs included in the TESC and SPCC plans and NPDES permit conditions will include, but will not be limited to, the following:

• Erosion control devices (e.g., silt fences) will be installed, as needed, to protect surface waters and other critical areas.

• Erosion control blankets, or an equally effective BMP will be installed, as needed, on steep slopes that are susceptible to erosion and where ground-disturbing activities have occurred.

This will prevent erosion and will assist with establishment of native vegetation.

• Material that may be temporarily stored for use in project activities will be covered with plastic or other impervious material during rain events to prevent sediments from being washed from the storage area to surface waters.

• All temporary and permanent erosion and sedimentation control measures will be inspected on a regular basis, maintained, and repaired to ensure continued performance of their intended function.

• Silt fences will be inspected after each rainfall and at least daily during prolonged rainfall.

• All equipment to be used for construction activities will be cleaned and inspected before arriving at the project site to ensure that no potentially hazardous materials are exposed, no leaks are present, and the equipment is functioning properly.

• Construction equipment and vehicles will be maintained to prevent them from leaking fuel or lubricants.

3.4.2 General BMPs for Construction Near Sensitive Areas:

The project proponent will ensure compliance with all local, state, and federal permits received for the project.

Reclamation’s Construction Contractor will delineate the boundaries of ground disturbance to prevent unintended effects on riparian vegetation, wetlands, woodlands, and other sensitive sites, both inside and outside of the construction limits, as applicable. The construction limits will be clearly marked with high-visibility construction fencing before any ground-disturbing or construction-related activities, and no work in sensitive areas will occur outside of the construction limits.

Reclamation’s Construction Contractor will implement measures to prevent erosion from soil or rock stockpiles, excavated materials, and excess soil materials into sensitive habitats, including water channels, wetlands, and riparian areas outside of the construction limits as a result of stormwater runoff.

3.4.3 Regulatory Controls:

The project will be constructed in accord with regulatory permits, including the Hydraulic Project Approval issued by WDFW.

Project construction will be performed in compliance with Washington State water quality rules (Washington Administrative Code [WAC] 173 201A 200).

Areas disturbed during construction will be restored with native vegetation suited to site conditions.

The US Forest Service will also be implementing a revegetation plan as part of the total Cle Elum Pool Raise Project.

Speelyi Shoreline Protection Project 5

Section 4 Specification Requirements

4.1 Dredging/Excavation

All work will be performed in the dry when the water level in the Cle Elum Reservoir is at least 50 feet away from the proposed work area. Excavation for the riprap key trench will generate the borrow material required to complete any fill portions of the project. If material unsuitable for fill is generated from the key trench excavation, additional material will be borrowed from within the project site limits for use as fill. Any borrow material taken will be subject to regrading the site to a natural contour and shape before work is accepted. Although there will be no water present during construction, the construction activities are still occurring below the ordinary high-water mark.

Therefore, if water were present, this activity would be dredging. Since excavating for the riprap key trench and grading for the riprap slope is occurring when water is absent, in the dry, this activity, though dredging-like, will be considered excavation for the purposes of this project.

4.2 Storm Water Pollution Prevention Plan

Construction work will be completed by Reclamation’s Construction Contractor who has not been identified at the time of preparation of this draft plan. The Contractor will be required to comply with all terms of the National Pollutant Discharge Elimination System (NPDES) stormwater permitting requirements (such as a Stormwater Pollution Prevention Plan) for this project. The current draft Construction Specification section 01 57 30 calls for the Contractor to submit a Pollution Prevention Plan as required for stormwater discharge from a construction site for approval at least 28 days before beginning any on site work. Work will not be allowed to start until the plan is approved.

Section 5 Permit Drawings

5.1 Drawings

Drawings have been provided with the permitting application showing the required construction work. Construction work will be completed by Reclamation’s Construction Contractor who has not been identified at the time of preparation of this draft plan. The Contractor will be required to finalize this plan and be subject to its requirements. Reclamation’s Construction Contractor will be required to finalize this draft plan and comply with it as a term of the construction contract, including performing all monitoring and reporting identified herein.

Speelyi Shoreline Protection Project 6

Section 6 Monitoring and Record Keeping

6.1 Monitoring

Visual and instrumental monitoring will be conducted throughout the life of the project during construction below the ordinary high-water level. Monitoring details (type of monitoring, how often data is recorded, etc.) is captured in Reclamation’s Draft Water Quality Management Plan.

Monitoring will occur as needed during the construction window if there is an event where water enters the construction area. If State Water Quality Standards are exceeded, Reclamation will issue a stop work order to the Construction Contractor until corrections are satisfactorily completed.

6.2 Record Keeping

Reclamation’s Contractor will record the time and location of water elevation changes throughout the construction period when and if water enters within the construction area. If water does enter the construction area at any point in time during the construction period, work will stop immediately, and records will be submitted to the Contracting Officer’s Representative for review.