What Do Green Shorelines Look Like?
Green Shorelines come in many shapes and sizes depending on site conditions (like slope, proximity of structures to the lakeshore, and wave energy). Planting shoreline vegetation can improve habitat and lake views on almost any property. A full beach restoration provides the greatest habitat benefits, but it may not be feasible for all properties. Below are some examples of different Green Shoreline approaches.
Use our interactive decision tool to find out which shoreline approach would work for your property.
Full Beach
Restoring a beach along your entire shoreline provides the greatest habitat improvement. It also creates a usable beach suitable for wading and other activities.
Designs: The Watershed Company Photos: City of Seattle |
Important considerations for a full beach restoration include:
- Beach Slope: Gradual slopes (7:1 of flatter) will resist erosion better and require less maintenance than steeper sloping beaches.
- Gravel Size: Although many people think of sand when they think of beaches, rounded gravel (1/8" to 2") will resist erosion better than sand, and provide more natural habitat. If you wish to incorporate sand into your design, it should be placed well above the high water line.
- Neighboring Bulkheads: A successful beach design will need to consider the neighboring shoreline. Rocks, wood, plantings, concrete walls, or even extra fill at the edges of your beach will help protect your shoreline from erosion caused by neighboring bulkheads. Better yet, partnering with your neighbors can create a more continuous shoreline, and with enough participation, you could be eligible for government grants.
- Periodic Maintenance: Some erosion is natural along beaches, so a properly installed beach restoration will need nourishment every five to ten years. In order to facilitate this, it is best to include periodic fill as part of the maintenance plan in your initial construction permit.
Beach Coves
A beach cove is a small beach on a portion of a property with hard structural features, like wood, rocks, or a bulkhead, on both sides. Beach coves provide an area for beach activities, as well as benefits to fish and wildlife, and they are among the most popular Green Shoreline approach in Lake Washington.
Design and Photos: Hendrikus Group |
Considerations for beach coves are similar to full beach restoration, and include:
- Beach Slope
- Gravel Size
- Erosion at Beach/Bulkhead Transition
- Periodic Maintenance
Special care should be taken in the design to minimize erosion at the transition from beach to bulkhead. Possible approaches to minimizing this erosion include sloping the ends of the bulkhead or adding extra gravel below the water line to prevent undercutting of the bulkhead.
Bulkhead Setback
If your home was built close to the lake, a bulkhead may actually be needed to protect it from erosion. By moving a bulkhead back several feet away from the water line, homeowners gain a beach for wading and beach activities, and improve lakeshore functions.
Bulkheads can be setback along the entire length of the property to create a reinforced full beach or along a portion of the bulkhead to create a reinforced beach cove.
Design and Photo: Marine Restoration and Construction, LLC | Design and Photo: The Berger Partnership |
Similar to full beach and beach cove restoration, you should consider the following before setting back your bulkhead:
- Gravel Size: After setting back your bulkhead, you will need to add beach fill (1/8" to 2" rounded gravel). This rounded beach gravel will resist erosion better than sand, so instead of losing property, you will be substituting lawn for beach. Similar to Full Beach and Beach Cove restoration, periodic beach nourishment will be needed.
- Bulkhead Slope: When you setback or replace your bulkhead, it is best to angle the slope of the bulkhead away from the water. Engineers generally recommend a bulkhead slope of 3:1 (run:rise). This will dissipate the wave energy, resulting in less erosion and it will reduce the amount of maintenance needed on your beach.
Bioengineering
Bioengineering means using natural features like plants and logs in place of, or in addition to, traditional structural protection. This approach provides a natural aesthetic and as well as improved ecological functions to fish.
Several wetland shrubs and trees can be planted by staking clippings from mature plants into moist soils. Willows, cottonwoods, and dogwoods can all be planted this way. Combinations of partially buried clipping bundles (fascines) and stakes can be also be used. As these plants grow, their roots stabilize the shoreline. King County provides more information on live plant staking.
Design and Photo: Marine Restoration and Construction, LLC | Design and Photo: The Berger Partnership |
Logs can can be strategically placed to provide functions similar to a traditional bulkhead, while creating a more natural look. Logs should be anchored into the beach, using cables or by partially burying them, to prevent them from drifting away during storms.
- Logs placed parallel to a shoreline can stabilize a beach.
- Logs placed perpendicular to shore can reduce erosion from lateral waves.
- Root wads extending into the water (but no more than 2' below the ordinary high water line) can provide habitat for young salmon.
Watch the Green Shores video from British Columbia.
Shoreline Makeovers: See before/after photos of Green Shoreline projects in Lakes Washington and Sammamish.
See for Yourself! Green Shorelines demonstration projects at local parks near you.
Shoreline Decision Tool: Find out which shoreline approach would work for your property.