Green Shores | Case Studies
Lake Washington Residence
↪ Green Shores for Homes project
Project Overview
| Location: Kirkland, WA | Project area: 0.19 acres |
| Year completed: 2011 | Awards: NA |
| Shoreline length: 36 m (118 feet) | Shore type: Lakeshore, sediment |
| Green Shores rating achieved: Chinook (Level 1) | Total points: 37 |
Site Description
The owners wished to build a larger house on this single-family lot on Lake Washington but needed to reduce some setback requirements. As compensation for the reduced setbacks, they replaced almost 50 feet of the 118-foot shoreline, which had been hardened with a bulkhead and riprap, with a soft shore design. Approximately 38 feet was left with sub-grade footings to provide structural integrity, and the remaining 40 feet was an unarmored beach cove. Where the bulkhead was removed, the owners re‑sloped the bank, revegetated the riparian area with native plants, and added gravel, boulders and logs to the shoreline.
Project Team and Affiliated Organizations
- Designer: Dar Webb, Darwin Webb Landscape Architects
- Contractor: Mark Putzke, Chandler Homes
Project Objectives
- Rebuild the single-family home and restore the shoreline through bulkhead removal.
- Enhance riparian function through addition of beach nourishment, woody material and native vegetation.
Work Plan
Almost 50 feet of the shoreline hardening was removed, leaving some below-grade footing in place for structural integrity. Short sections of bulkhead were retained to tie into the neighbouring property to the north and to protect a tree to the south. The shoreline was then re-sloped, and beach nourishment of gravel, boulders and logs were added. Removal of invasive vegetation and planting of native plants was also completed.
Description of how the project meets Green Shores principles
> Maintained/ Enhanced Habitat Function and Diversity
- About 30 percent of the riparian buffer was revegetated with native plants. A monitoring and maintenance plan was adopted to ensure that no chemical pesticides or fertilizer were used in the shoreline planting area.
- A large tree protected at the south end of the property provided the benefits of overhanging vegetation.
> Preserved/Restored Shoreline Physical Processes
- With 50 feet of armouring removed from the 118-foot shoreline, the project qualified for 25‑49 percent net bulkhead removal. In addition, points were awarded for maintaining and enhancing the unarmored cove that occupied about 34 percent of the shoreline.
- The owners included monitoring the shoreline improvements for five years in an adopted shoreline maintenance plan.
- Large logs added to the beach decreased wave intensity and provided habitat value.
- The new pier and dock surfaces are entirely grated to allow light penetration to the water below. Lighting fixtures were installed to ensure that light was directed laterally and not downward to the water or upward to the sky, where it could impact migrating fish or birds.
> Ecological Services Provided
- Riparian habitat that supports native flora and fauna.
- Shoreline erosion control.
> Shoreline Collaboration and Public Education
- The owners provided opportunities for this property to be used for on site testing of preliminary GSH credit and rating system guides and for training of GSH verifiers.
> Additional Notes
- Although more than 50 percent of the upland lot area was covered in impervious surfaces, almost all the surface runoff was directed to a large cistern, and the stored water was used for irrigation and toilet flushing. Any overflow was directed through a constructed rock swale.
- All materials used for the pier, dock and landscaping were left untreated, with no chemical paints or stains applied to the surfaces.
