Building Resilience with Natural Adaptations to Change

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 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:

• By removing 1/3 mile and 1340 tons of rip rap/concrete/creosoted bulkhead and non- native plants, the project is allowing the shore and the sea to naturally reconnect – restoring shoreline processes, structure, and functions to the maximum extent practicable.

• By removing almost an acre of invasive and non-native plants along the shore and uplands and planting over 2500 native plants, there is a more diverse plant and tree habitat, which provides shelter and food for insects and birds, and shade along the shore, which is important for fish. Salt marsh vegetation was enhanced by providing more intertidal area after removal of bulkheads.

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.