HAT ISLAND MARINA BASIN REHABILITATION
Hat Island, Washington

The Hat Island Community requested that Coast & Harbor Engineering (CHE) perform a feasibility engineering analysis for improving marina facilities of the Hat Island community marina. These improvements included the repair, upgrading, or replacement of bulkheads, boat ramp, navigation channel, wave protection, and floats and gangways. CHE developed alternatives and order-of-magnitude costs for all the elements of the Basin Rehabilitation Project, and proposed a phased approach to project implementation, which included an option for marina basin expansion. Based on this information, the Hat Island Community selected project elements for proceeding to the second phase of the project, preliminary engineering and permitting. The project is currently ongoing.

CHE Performed the following project tasks:

		Historical data review including marina condition survey and site constraints
		Bulkhead stability analysis to determine pile embedment and size requirements, waler and tieback requirements, and deadman type and size requirements
		Developed site plans with reconfigured slip layout and requirements including finger pier, mainwalk, gangway, guide pile preliminary sizing
		Performed 2-Dimensional numerical models to simulate wave propagation through the entrance into the marina
		Developed a preliminary dredging plan and identified possible permitting issues
		Rock revetment stone gradation sizing for bulkhead toe buttress if required
		Existing facility demolition and relocation requirements
		Construction materials evaluation for marina structures
		Budgetary level Construction Cost Estimating