Bainbridge Island, located in the heart of Washington’s Puget Sound, is known for its rural character, thriving arts culture, and close proximity to the City of Seattle. A short ferry trip away from Seattle, Bainbridge Island is home to families and individuals who share an appreciation of the Island’s unique natural features. Bainbridge Island offers opportunities to engage in a wide range of outdoor recreation – from hiking or biking along an extensive network of trails to kayaking throughout the various harbors and inlets. Because of their idyllic location, Bainbridge has been experiencing increasing development pressure, especially along their 53 miles of shorelines. The Bainbridge Island Land Trust (BILT) was started in 1989 by a group of residents who were concerned about balancing growth and conservation needs on this 65 square mile island. The Bainbridge Island Land Trust’s work exemplifies efforts to preserve the many values inherent in the rural Pacific Northwest landscapes and wildlife of this region.
Coastal processes are dynamic and shoreline ecosystems experience constant change. In the Pacific Northwest, these shallow coastal systems are essential to juvenile salmonids – particularly the Endangered Species Act-listed Chinook – for migration, feeding, refuge, and physiological transition. Despite their many ecological and aesthetic values, historically, coastal landowners have been prone to “harden” their shorelines in a perceived effort to fend of wave energy and natural shoreline processes such as erosion.
Bulkhead construction along shorelines, also known as “armoring”, is a type of “hard” shoreline modification that is often used to dissipate wave energy. Unfortunately, these practices can cause down-gradient impacts as well as habitat loss. In a 2001 white paper, the Washington Department of Fish and Wildlife noted that such structures can severely impact nearshore coastal resources, and recommended minimizing these impacts by using alternative (“soft”) modification strategies and, when possible, restoring impacted sites to “natural” conditions. As sea levels rise and wave energy due to strengthening storms increases, protecting resilient coastal systems that can mitigate these impacts and adapt to these changes becomes increasingly important to enhance the chances of survival for valuable coastal habitats and communities.
In 2004 the City of Bainbridge Island conducted its Nearshore Habitat Assessment to inform restoration and conservation efforts as well as the City’s Shoreline Management Update and Salmon Recovery Planning.
Port Madison Bay was assessed as being “moderately impacted” and the report acknowledged that the area provided opportunities for improvement, specifically by removing or minimizing shoreline armoring. This report not only provided valuable baseline information about the Bainbridge Island shoreline – it also produced policy guidance encouraging five fundamental nearshore management strategies (listed here alphabetically): conservation, creation, enhancement, preservation, and restoration (see Appendix E of the report). This report emphasized the ecological value of the Port Madison Bay nearshore area and articulated the importance of removing or reducing shoreline armoring to achieve conservation values.
Several years later, in 2008, the Powel family requested advice and technical assistance from the City of Bainbridge Island and BILT (who holds a conservation easement on the Powel property) on rebuilding a failing bulkhead. In 2009, BILT and the Powel family invited a number of shoreline ecologists, state, and tribal experts to the property to evaluate the property and the discussion turned from replacing the bulkhead to potential restoration options.
BILT agreed to work with the family to find funding support to design a shoreline restoration project. Due to the fact that juvenile salmon and forage fish have been documented on the site, and that the reestablishment of shallow intertidal areas would help the recovery efforts for these species throughout the Puget Sound, this project obtained a grant from the Puget Sound Acquisition and Restoration Fund through the Washington Salmon Recovery Funding Board for the design phase. By the end of the 18-month planning window, with extensive feedback from the Powel family and other stakeholders, the engineered design plan envisioned restoring more than 1,500 linear feet of nearshore habitat. In 2011 implementation funding was obtained through the Washington Salmon Recovery Board, which, along with funds from the family and BILT, covered costs of permitting as well as hiring armor removal contractors, restoration specialists, project engineers, and other elements of project implementation. Removal of over a quarter mile of shoreline armoring, fill, and debris began in August of 2012, and removal of invasive plants in the riparian area, the installation of a fish screen on an intake pipe, and revegetation was completed in early winter.
Bainbridge Island’s Powel Shoreline Restoration Project highlights how natural intervention options can reduce wave energy impacts while addressing lost salt marsh, enriching intertidal habitats, and fostering marine riparian habitat by recreating shallow intertidal habitat. The benefits of the Powel Shoreline Restoration extend upland as well – as native salt marshes regrow on the previously armored shoreline, natural transitional zones and associated processes such as sediment accretion can recover. These eco-zones and processes support salt marsh and upland flora and fauna and increase the resilience of these systems.
After nearly three and a half years of planning and two seasons of project implementation, the Powel Shoreline Restoration Project was completed in May 2015. BILT continues to have an active role in monitoring the results. After six years of planning and implementation, initial observations indicate that:
Already, intertidal marsh is recovering. The project hopes to increase the healthy intertidal area by 163%.
This was the first major restoration project undertaken by BILT and serves as a shining example of the important role BILT plays in recovery of salmon and the health of the Puget Sound marine ecosystem by working with private landowners to improve habitats of all kinds on conservation properties. As the largest shoreline restoration project on private property in Puget Sound, the Powel Shoreline Restoration Project is an illustrative outreach project that exemplifies balancing ecological restoration goals with the needs of the landowner.
A failing bulkhead on the Powel property, which was placed under a conservation easement with BILT in 1993, began a dialog with the landowners and the Land Trust to assess restoration options on the property. The conservation-minded landowners worked with the Land Trust to reach out to interested stakeholders to begin an extensive planning process that expanded the limited discussion of how to address one failing bulkhead to an intensive collaborative effort to improve nearly a quarter mile of previously armored shoreline. Considerable resources were devoted to a thorough design phase, which included sea level rise mapping and communication with the landowners, outreach to potentially concerned parties such as the Army Corps and the local Suquamish Tribe, and the completion of a Cultural Resources Assessment. By conducting a resource assessment and bringing these stakeholders to the table early in the process, the project avoided potential conflicts in the implementation phase. The land owners were involved in every aspect of the project. Moreover, BILT understands that it is not only is it important to protect and conserve lands but to also help the community take care of them – over 1200 volunteer hours have been involved in all aspects of the project to date.
Since its founding in 1989, the Bainbridge Island Land Trust has helped to protect over 1,300 acres of vulnerable forestlands, wetlands, meadows, shorelines, agricultural lands, riparian corridors and scenic vistas, of which more than 950 acres are open to the public.
4 full-time, 2 part-time; 15 volunteer board members
The Bainbridge Island Land Trust has over 750 members.
The Powel Shoreline Restoration Project on Bainbridge Island restored nearly a quarter mile of privately owned shoreline by removing bulkheading (armor). These efforts have enhanced coastal habitats, including an overall increase of 163 percent in current intertidal habitat area associated with the project property, almost tripling the amount of salt marsh habitat on the property, and improving 32,795 square feet of marine riparian habitat. Numerous native plants were planted to improve the riparian area. Natural nearshore processes will take place to enhance ecological structure and natural functions, supporting a more resilient shoreline over time.
The Powel Shoreline Restoration Project targeted an 11.8 acre property in Port Madison, on Bainbridge Island.
Open to the public with prior notice to and consent from landowners
Bulkheads have been used as a defense to reduce shoreline erosion, but they are limited in their function and cause inherent harm to nearshore marine ecosystems. Adverse effects include:
Case Study Based on BILT Publications and Co-authored by Brenda Padgham