SECTION C

PROJECT SPECIFICATIONS AND DRAWINGS

Stevenson Shoreline Restoration and Recreation Enhancement Project

Stevenson Waterfront, Stevenson, WA

Public Works Contract Solicitation

June 2, 2017

The objective of the Stevenson Shoreline Restoration and Recreation Enhancement Project is to arrest 450 feet of severe bank erosion and restore aquatic habitat along 1,250 feet of Columbia River bank. The project entails extending the shoreline on average 78 feet to the south from the existing shoreline. An estimated 35,000 cubic yards of rock and soil will be placed to restore the shoreline and enhance aquatic and riparian habitats. The proposed project restores the footprint of the historic river bank. The project area is located between points 45.6195 N, 121.8817 W and 45.6930 N, 121.8779 W within the city limits Section 31, T.3N. , R.8E.

Scope of Contract

Supply equipment and operators for the restoration of river bank and removal of sheet pile along the Stevenson, Washington waterfront. Contractor assumes all equipment, labor, supervision, transportation, operating supplies and incidental cost.

PART 1 GENERAL

1.1 SECTION INCLUDES
A These specifications inform all interested parties about the equipment and machinery needed and the nature of the work required to successfully complete a restoration of 1,250 feet of shoreline.
B The Contractor is responsible for providing specified materials, equipment and operators to perform the work.
1.2 PERSONNEL AND EQUIPMENT
A The contractor shall supply capable and experienced and licensed personnel, and suitable equipment to perform this work. Each Bidder shall also furnish with the bid additional information that shows:
1 Experience records of the contractor on in-water restoration projects of this type.
2 Manufacturer's name, year and model of equipment to be used.

PART 2 DESCRIPTION OF WORK

The objective of this project is to restore river bank stability along 1,250 feet of Columbia River shoreline. In general the work under this Contract includes, but is not limited to, the following major items of work. The following descriptions provide an outline of major work items and shall not be construed as an exhaustive or complete listing of all items of work under this Contract.

The Contractor will supply materials, equipment and operators to complete the following items:

2.1  Sheet Pile Removal
One-hundred and twenty feet (120) of sheet pile shall be removed from Leavens point. Sheet pile removal may include cutting the pile with torches or by other means at the existing ground elevation. The Contractor is responsible for disposal of the sheet pile.
2.2  Dredging, Sorting, Hauling and Stockpiling Substrate
Boulders, cobble, gravel, sand and topsoil will be loaded and hauled from Port properties in North Bonneville, WA and also dredged, sorted and hauled from Rock Creek near the confluence of the Columbia River in Stevenson, WA to the project site.
Locations of the North Bonneville boulder and rock stockpile sites are shown on the Borrow Areas Map (Exhibit B). The contractor is responsible for mobilizing equipment to each site and stockpiling material as directed by the Port project manager.

Rock Creek will be dredged in areas specified and marked by the Port project manager. Boulders, cobble, gravel and sand will be dredged and sorted on Skamania County property adjacent to Rock Creek. Power screens or grizzly substrate sorters or other means proposed by the Contractor may be used to sort and stockpile material.

The various substrate sizes and quantities will be delivered to the project site in sequence directed by the Port project manager. Traffic control and public safety are the responsibility of the contractor.

Dredging will occur during the permitted in-water work window. Various dewatering and turbidity control measures will be employed according to the Port’s project manager’s direction.

2.3  Temporary Access Routes
The limits of temporary access routes will be marked by the Port project manager. Access to the river will be at the discretion of the Contractor.
2.4  Sediment Curtains
Sediment curtains will be deployed in the Columbia River in 200 foot sections or greater prior to construction. The Contractor is responsible for maintaining sediment curtains and turbidity control during construction. The project will occur during the permitted Columbia River in-water work window, which is November through January. During this time period frequent East wind events will occur. The Contractor must be prepared to take measures to secure the sediment curtains and maintain turbidity control during these events.
2.5  Shoreline and Beach Restoration
Detailed site diagrams, grading and excavation details are provided in Attachment A Project Plans. The Contractor shall provide an erosion control and spill prevention plan before mobilization to the site.
Boulder cobble fill will initially be imported and placed parallel to the shoreline at an elevation of at least 1 foot above the existing water level elevation forming the base layer. The base layer boulder and cobble fill will continue in vertical and horizontal lifts until the project fill limit to the South is achieved per the attached project plans. Sand and fines will be mixed with each lift to fill voids and promote compaction. Gravel and fines will then be imported in lifts to fill the interstitial spaces of the boulders and cobble layer. The gravel-fine lifts will continue, sloping north to the upper limits of the project area (top of bank elevation). Gravel will be imported and placed along the toe of the project limits (southern edge) to create a gradual sloping gravel beach.
2.6  Rock and Rootwad Structures
Rootwad-boulder structures will be constructed and incorporated into the base layer per the attached project plans. Trees with attached rootwads will be collected from Rock Creek and delivered to the project site. Trees will be identified, marked and tree lengths specified by the Port project manager. Roots of the trees selected will be left intact and undamaged during harvest and delivery.
2.7  Riparian Restoration
Topsoil will be imported from areas designated by the Port project manager and spread throughout the planting area. Topsoil will be applied in lifts with minimum depths of 6 inches. Topsoil will be covered with coir fabric and then planted.
2.8  Dredge Sorting Site and Access Route Rehabilitation
All disturbed areas shall be rehabilitated per the direction and specifications of the Port’s project manager.

PART 3 EXECUTION

3.1  RECORDS: Daily logs of equipment and operator hours shall be kept. Hours recorded shall only include periods of equipment operation; hours used for maintenance, fueling and breakdowns will not be recorded or paid for by the Port. Electronic copies of the logs shall be given to the Port’s project manager on a weekly basis.

Port of Skamania County, Stevenson, WA SECTION C

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