Shorelines Slope Planning Stabilization
Slope and shore integrity are critical to homeowners in these environments. Integrating your view, slope integrity and shoreline processes requires long-term planning, permitting and management.
Benefits of Green Shorelines
Washington's Shorelines are our states treasures. From Clallam County, Jefferson and Kitsap, the State shorelines provide opportunities for recreation, beautiful views, and habitat for salmon and other fish and wildlife. Over the past century, people have built houses along marine, river and lake shorelines because of the opportunities for aesthetics, views, recreation and enjoyment that they provide.
As homes were built, people alter shorelines by removing trees and dead wood from the landscape and by building bulkheads. Concrete or rock wall bulkheads negatively impact fish and wildlife habitat. They can actually accelerate erosion by increasing wave energy. More sustainable Green Shoreline alternatives use live plants, beaches, and wood to protect houses while improving habitat for native fish and wildlife, views, and recreational opportunities. Green shoreline alternatives are designed to create a more gradual sloping shoreline and overhanging vegetation to provide protected, shallow water habitat needed by juvenile Chinook salmon and a food source for native birds and wildlife.
Benefits of Green Shorelines for Property Owners:
- Easier access to beach and water.
- Shallow gradient shorelines are often favored over steeper designs, especially if you have small children.
- More usable shoreline with beach and cove.
- Reduced maintenance.
- Potential for increased property values.
- The pleasure of knowing that there are salmon rearing off your shore.
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 shoreline or 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.
Restoring a beach along your entire shoreline provides the greatest habitat improvement. It also creates a usable beach suitable for wading and other activities.
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.
If your home was built close to a shoreline, 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 shoreline 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.
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.
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 Washington shorelines.
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.
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.
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.
Why Shoreline Planting?
Natural vegetation along the shoreline provides several benefits to the landowner and native fish and wildlife.
Native vegetation adds visual appeal and frames shorelines views. Since native plants are adapted to live in the Pacific Northwest, they generally require less maintenance than a lawn or ornamental plants. Vegetation hanging over the shoreline provides cover for juvenile Chinook salmon. Insects feed on native vegetation, and then they become food for juvenile Chinook salmon when they fall onto the surface of the water. Dense vegetation filters out pollutants, so vegetated buffer areas also help keep our lake water clean. For a list of native plants, and to create your own custom plant list, see the King County Native Plant Guide.
Call us Today!
We offer environmental and ecological permitting of trees and vegetation management. If you're in a critical area or environmentally sensitiveness area and your county or city requires permits, I can walk you through the process of obtaining a permit. For those interested, I provide a full turn-key vegetation management perspective, beginning with consultation, to editing the landscape, to reinstalling native plants.
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Green Shorelines Blog
Information from this page sourced from Salmon Conservation and Restoration - Greening Your Shoreline program.