shorelinesGREEN Bulkhead alternatives for a healthier Lake Washington Design and Photo: Darwin Webb 2 Landscape Architects 3 Lake Washington embodies the best of Western Washington: clean water, bountiful recreational opportunities, striking mountain views, and access to thriving cities. These qualities have inspired thousands of people to make their homes on the shores of the lake, transforming a forested waterfront to a residential one over the past 100 years. This change has led to a variety of problems, including loss of important wildlife habitat and some of the area’s natural charm, but lakefront homeowners are fi nding new ways to protect the lake. Contents This guidebook is about alternatives to the use of bulk- heads and other shoreline armoring. Hard engineering is GREEN SHORELINES Introduction 4 currently the standard approach for erosion control around the lake, but it has several negative impacts on nearshore Bulkhead alternatives for a habitats as well as the fi sh and wildlife that depend on healthier Lake Washington Green Shoreline Practices them. More sustainable practices, referred to in this Full Beaches 6 guidebook as green shorelines, use plants, beaches, and note Beach Coves 8 other natural materials to protect private property and the Setting Back Bulkheads 10 environment. Log installation 12 Shoreline Plantings Vegetated Buffers 12 Green shorelines provide three types Slope Bioengineering 14 of benefi ts for homeowners: Plant List 18 1 they substantially improve habitat for Chinook salmon While homeowners often fi nd green shorelines attrac- and other wildlife while maintaining shoreline stability; tive, many have concerns about effectiveness, reliability, Selecting the Right Approach 20 building and maintenance costs, the permitting process, 2 they allow improved water access for homeowners and and the potential loss of lawn. This guidebook specifi cally Building Better Docks 22 guests, making swimming and shoreline enjoyment addresses these and other concerns by assembling technical easier; information from a wide range of sources and providing Estimated Costs and Maintenance 24 local examples. 3 they offer a softer, more natural aesthetic that can Choosing a Shoreline Professional 26 enhance views by adding variety and seasonal interest. Although the guidebook was written by the City of Seattle, the principles described here can be applied to homes Getting Permits 28 all around Lake Washington. Additionally, most of the information provided here is relevant to Lake Sammamish. Technical advice in these pages is offered as guidance; Resources 32 it is not building code. In the case of any discrepancies, defer to local, state, and federal regulations for shoreline Contacts 33 development. Glossary 34 Green shorelines are attractive, reliable, and sustainable. The idea of having your own beach is a Acknowledgements 35 major motivator for many people to buy waterfront property – why give up your beach for a bulkhead? GREEN SHORELINES: BULKHEAD ALTERNATIVES FOR A HEALTHIER LAKE WASHINGTON INTRODUCTION Design and Photo: Ecco Design Inc. The following sections explain and illustrate how these 4 approaches work, where they might be used, and what they 5 look like. Although described separately, keep in mind that in most cases, these strategies are typically used in combi- nation with one another. While the concepts outlined here will give you a broader understanding of the options for Bulkheads and docks have altered or eliminated much of improving your shoreline, it is advisable for you to seek the shallow-water habitat around the lake. A 2001 study professional assistance to get your project designed and found that 70% of Lake Washington’s shoreline was built. Suggestions for selecting designers and contractors armored with concrete, riprap, sheetpile, or another type are provided in the section titled “Choosing a Shoreline of bulkhead. By refl ecting wave energy back into the lake, Professional.” these structures tend to wash away nearshore sediment, note causing deeper water over time. Lawns have replaced much When this guidebook uses the term “restoration,” it does of the diverse vegetation that provided cover for young not mean returning Lake Washington to its pre-development fi sh. While many factors are contributing to the decline of condition. Rather, it refers to restoring specifi c ecological Puget Sound’s endangered Chinook salmon populations, processes. The shorelines shown in this publication look dif- loss of rearing and refuge habitat is among the most seri- ferent than they did 150 years ago, but they still can protect ous problems. fi sh, wildlife, and water quality in many of the same ways. Bulkheads also can compromise homeowners’ access to Together with design and construction advice, this guide- the water and negatively affect views. Entering the water book also provides suggestions to help you get through from a bulkhead can be awkward or even dangerous; your permitting process more quickly. Because Lake shoreline armoring accelerates nearshore erosion, deepen- Washington is home to multiple species on the Endangered ing the water and making wading diffi cult. Further, the Species list, lakeshore construction has to be approved by widespread use of shoreline armoring is bad for waterfront local, state, and federal agencies. While specifi cs vary, the aesthetics—while homeowners typically prefer greener, growing trend across regulatory agencies is to encourage natural-looking lakeshores, armoring creates a more heavily projects that improve shoreline habitat quality through developed look along the shoreline. requirements, incentives, and streamlined permitting. Fol- lowing the principles in this guidebook can help you avoid Introduction Attractive alternatives unnecessary permitting hurdles (see “Getting Permits”). The good news is that people are fi nding new strategies Photos of restored shorelines throughout the guidebook for protecting their property while also protecting and help demonstrate specifi c green shoreline techniques, and restoring habitat. Instead of concrete and sheetpile, these they also display the aesthetic benefi ts of natural beaches The water’s edge Problems with “business as usual” practices use a combination of plantings, gravel, stone, and plantings. Further, they provide samples of the diverse logs, and slope modifi cation to protect against shoreline shoreline restoration projects that already exist around People love to live in places where water and land meet. Unfortunately, some of the natural elements that attract erosion. Lake Washington. Shorelines provide work and recreation opportunities, mild people to waterfront properties are often casualties of climates, and tranquil views. Rapid growth in the commu- development. Trees, shrubs, and wildfl owers are cleared to The ideal is to set structures back far enough to preserve nities around Lake Washington and Lake Sammamish is a make way for houses, lawns, and open views. Bulkheads the natural shoreline and vegetation. However, given that clear demonstration of our desire to live near water. built to control bank erosion displace beaches and cause the majority of Lake Washington is already developed, this erosion below the water line. Removal of vegetation along guidebook focuses on positive steps that can be taken to People are not the only ones drawn to shorelines, however. the shore allows contaminants to fl ow directly into the reduce the impact of existing waterfront homes. Whether Due to the diverse resources and habitats that occur along lake. As beaches and vegetation are replaced by lawn and your site can accommodate a full beach restoration or only lakeshores, they tend to be biologically rich and productive concrete, prime wildlife habitat disappears, taking with it incremental improvements, a wide range of options is places. Again, Lake Washington is no exception—numer- birds, benefi cial insects, and fi sh. available, including: ous plant, bird, fi sh, mammal, and insect species call the lake’s shorelines home. Residential development on Lake Washington has taken a Full beaches particularly heavy toll on Chinook salmon. These iconic Beach coves fi sh of the Pacifi c Northwest hatch in the Cedar River, Setting back bulkheads Issaquah Creek, and Bear Creek. Many rear in the lake for Log installation several months. Once they become smolts, Chinook swim Vegetated buffers through Lake Washington and Seattle’s Ship Canal to reach Slope bioengineering the ocean. As they migrate through the lake, juveniles fol- low the shoreline, staying close to the shallow-water areas that help them to escape from predators and safely forage for food. GREEN SHORELINES: BULKHEAD ALTERNATIVES FOR A HEALTHIER LAKE WASHINGTON GREEN SHORELINE PRACTICES: FULL BEACHES Design: The Watershed Company Slopes of 7:1 or less are ideal for Planting Design: The Berger Partnership restored beaches, although slopes 6 up to 4:1 can be stable. 7 7' 7:1 slope 4' Plants create habitat & visual interest while framing views 4:1 slope 1' 1' If structural Sand play area, reinforcement is separated from required, place as far gravel beach back as possible Beach slope is a critical component of a successful restora- Rocks and fi ll meet tion project. A well-designed slope provides resistance to neighbor's bulkhead erosion, reducing the need for maintenance. Slopes of 7:1 or fl atter are ideal (seven horizontal feet for each vertical foot), Former bulkhead but slopes up to 4:1 can be stable in some circumstances. Sloping beach Rocks separate New beaches should