Green Shores | Case Studies
East Shore Lake Washington Residence
↪ Green Shores for Homes project
Project Overview
| Location: Kirkland, WA | Project area: 1.01 acres |
| Year completed: 2012 | Awards: 2020 Honour Award from the American Association of Landscape Architects |
| Shoreline length: 46 m (150 feet) | Shore type: Lakeshore, sediment |
| Green Shores rating achieved: Chinook (Level 1) | Total points: 32 |
Site Description
This property is located on the east shore of Lake Washington in a residential neighbourhood. Wishing to replace the ageing concrete bulkhead that extended the length of the shoreline and to remodel the guest house that stood some 20 feet from the shoreline, the owners were attracted to ‘natural shore’ methods used to protect the shoreline in a nearby park.
Project Team and Affiliated Organizations
- Designer: Paul Broadhurst
- Contractor: Bill Rissel Stillwater Marine Construction
Project Objectives
- Remove an ageing concrete bulkhead
- Apply nature-based solutions to restore the shoreline and provide spawning habitat for salmon.
Work Plan
The owners had the bulkhead removed, along with a shoreline gazebo, lawn, and ornamental shrubs that extended from the house to the bulkhead. The riparian area was then re-sloped and revegetated with native plantings.
Description of how the project meets Green Shores principles
> Maintained/ Enhanced Habitat Function and Diversity
- The project had native vegetation planted and maintained in over 70% of the riparian buffer through application of an approved monitoring and maintenance plan.
- The landscaping was installed, monitored and managed for a minimum of 3 years without the use of synthetic pesticides, herbicides and fertilizers.
- About 10-20% of the shoreline was planted with emergent and overhanging vegetation.
- This included planting of a minimum of 6 large trees (>4 inches in diameter at breast height) in the riparian buffer.
- Woody material was added to some 20-30% of the shoreline to attenuate wave energy and add habitat complexity.
- The riparian area was resloped and had a mix of cobble/gravel added. Onto this surface, a layer of spawning gravel was placed to enhance shallow water habitat for salmon.
- The new shoreline access path was designed to minimize impact on the riparian buffer.
> Preserved/Restored Shoreline Physical Processes
- The house and accessory buildings met the setback from the ordinary high water mark (OHWM) required by the City of Kirkland.
- While the entire 150-ft concrete bulkhead was removed, about 85 feet were replaced with a partial revetment of boulders, creating a net bulkhead removal of less than 50%.
- Boulders and large woody debris were added to the gravel beach to assist with wave attenuation.
> Ecological Services Provided
- Site stability and erosion control were improved.
- The spawning habitat was enhanced for salmon.
- New overwater structures – a dock and ramp, were built but were assigned points for having relatively narrow surface area, no lighting, and surface grating that allowed significant light penetration. Points were also awarded for using untreated building materials and no chemical stains on the overwater structures.
> Shoreline Collaboration and Public Education
- The owners collaborated with Washington Sea Grant and SCBC to have their property made available to the GSH program for both pilot testing and verifier training.
