Welcome to the latest edition of the WSU Shore Stewards News. We offer periodic newsletters about timely topics for thousands of Shore Stewards around Puget Sound. Be sure to visit our website, which includes informative videos about living on and near our shores.
This issue of the Jefferson/Clallam County WSU Extension Shore Stewards newsletter was originally published as two newsletters written by Scott Chase, WSU Shore Stewards Coordinator in Island County. Many thanks to Scott.
Cheers!
Cheryl Lowe, Water Programs Coordinator, Jefferson WSU Extension
Experts acknowledge that not all locations are suited to these options. The photos below illustrate a situation in which replacing a section of an existing bulkhead with a more natural shoreline was considered, but not recommended following a site visit by a well-known engineer who specializes in soft-shore alternatives. The continuous wood and rocky groin bulkhead, located in front of multiple properties and just a few feet away from structures, sheds and access trails, is not a good candidate for replacement by more natural alternatives. Removing a short section of bulkhead in a location like this one would likely result in erosion for the property owner and neighboring properties. It is highly unlikely that a property owner today would be allowed to construct any structures so close to the shoreline, but until recently, this was common in many coastal communities.
Camano Island Photos by Scott Chase
Large Wood Placement
Large drift logs and root wads (large woody debris) are readily available on the upper beach tidal zones of Puget Sound, and are being increasingly used in alternative or “natural” shoreline protection projects. As part of a professionally engineered project, the logs are often anchored perpendicular or at an angle to the shoreline, with different results. They can be used to disperse wave energy, or to corral additional wood debris, sand or beach sediment. Logs that are lower on the beach and subject to wave energy may be partially buried, whereas logs higher on the beach may be more loosely placed and used to protect vegetation, which in turn protects against erosion. When possible, logs should be large, with root wads and branches left intact when possible, and include naturally rot-resistant varieties such as red cedar and Douglas fir. This method of shoreline protection is often used in conjunction with revegetation and beach nourishment. The photos below show how creosote bulkheads at Cornet Bay on Whidbey Island were replaced by a more natural, sloping beach, with anchored logs placed both parallel to the shoreline on the upper beach area, and also perpendicular to act like a groin. Native vegetation has replaced the grass on the upper beach to protect against erosion.
Photos above by Sarah Schmidt
Photo above by Scott Chase
Large wood placement should always be designed and implemented by a professional who has experience with this method, and has knowledge of coastal processes. Some property owners may attempt to create their own large wood placement, with mixed results. The log photo above is an example of a property owner who used cables and ropes to tie dozens of logs together, adding new ones as they washed up. This has resulted in upper beach erosion.
Beach Nourishment
For many low to medium wave energy sites around Puget Sound, beach nourishment is often used to slow erosion and restore beach conditions to more closely resemble past conditions. Used primarily with small scale projects, nearby upland coarse sediments are placed in backshore and upper beach areas to create protective berms. The use of rounded gravel and sand to create a gradual beach grade differs from larger beach-fill situations that increase the height and width of beaches. It is best to match sediment size as closely as possible to the natural sediment found on the beach. The objective is to slow beach erosion by allowing the beach to replicate a natural one. Erosion continues to take place, so periodic material additions may be needed. This method works best in locations where the waves break parallel to the beach, rather than breaking at an angle, which typically causes more erosion and sediment movement. Beach nourishment is often used along with large wood placement.
When considering beach nourishment, it is very important to consult with a professional who is experienced with this technique and understands coastal processes, like a geotechnical engineer or coastal geologist. This is a relatively low-cost alternative that will help you replicate a more natural looking beach.
The photo at left, courtesy of Hugh Shipman, Washington State Dept. of Ecology, shows a nourishment project from the north side of Weaverling Spit on southern Fidalgo Bay. This was undertaken several years ago.
The 2005 Marine Park Beach restoration project in Bellingham included the replacement of 5,600 tons of concrete rubble and rock on the shoreline with a gently sloping 300 foot wide sand and cobble beach. Photo below: courtesy of Hugh Shipman.
Reslope and Revegetation
In locations where there is slope instability due to erosion of the bluff toe, or upland causes that create an over-steep and unstable upper bluff face, resloping (or recontouring) may be a relatively inexpensive and natural solution. This may be done in conjunction with site drainage and vegetation management. If the location, however, is currently in a relatively stable condition or has ample native vegetation, the benefits may be offset by the disturbance of the slope caused by resloping. This alternative may also not be feasible for locations with erosion caused solely by wave energy.
Bluff resloping and revegetation refers to the reduction or lowering of the slope’s grade to increase stability, accompanied by the planting of vegetation, preferably native species best suited for marine environments. Generally, the upper portion of a steep slope is graded so that the crest of the slope is laid back. Vegetation is then planted to intercept precipitation and thereby reduce surface erosion and surface water runoff. The root network will increase soil cohesion and reduce the erosion of the surface soils on the bluff. The roots will also help aerate the soil, as well as wicking the water from the soil and evaporating it into the air through the leaves of the vegetation, a process known as evapotranspiration. This helps reduce the quantity and weight of the water on the bluff, lessening the chance of slides.
In more serious situations, engineered structural solutions may be considered when resloping, including crib walls, gabion walls, and other soil- erosion due to high energy wave activity. Information on these is not covered in this newsletter. In some instances, resloping and revegetation may be done along with beach nourishment or use of large log placement.
Photos courtesy Washington Dept. of Fish and Wildlife
The two photos above illustrate reslope and revegetation undertaken at a medium-high bank site in Puget Sound. A bluff slump had left the upper bluff area overly steep and unstable, with the sediment accumulating at the toe. The slope was regraded, then planted with appropriate native species.
Rethinking Shoreline Armoring – A series of Salish Sea Currents magazine. Encyclopedia of Puget Sound. (The Encyclopedia of Puget Sound is published by the University of Washington’s Puget Sound Institute) https://www.eopugetsound.org/magazine/shoreline-armoring
Shipman, H., Dethier, M.N., Gelfenbaum, G., Fresh, K.L., and Dinicola, R.S., eds., 2010, Puget Sound Shorelines and the Impacts of Armoring—Proceedings of a State of the Science Workshop, May 2009: U.S. Geological Survey Scientific Investigations Report http://pubs.usgs.gov/sir/2010/5254/pdf/sir20105254.pdf
Menashe, E., 2004. Shoreline Management and Stabilization Using Vegetation. Greenbelt Consulting, Clinton, Washington. http://greenbeltconsulting.com/ctp.html
(Here’s the second “chapter” of the Island County Shore Stewards newsletter)
Evaluating Shoreline Protection Options
By Scott Chase, Island County WSU Shore Stewards Coordinator
Planning Your Property’s Future
Perhaps you were able to find a piece of undeveloped waterfront property along Puget Sound, and are now preparing to plan every step in its development. Possibly you purchased an existing shoreline bluff home, and are considering what you can do to protect it from erosion. Or you may have concerns about the property and house that’s been in your family for decades, and what to do when the old, deteriorating bulkhead topples over in a winter storm. The following should provide some thoughts on what you can do to minimize erosion, while at the same time protecting your property’s wildlife habitat.
Undeveloped Property: The Property Assessment
One of the best actions you can take at this stage would be to do a site assessment of your property, which will help you understand the location and amount of erosion taking place, as well as what is causing the erosion. This could include hiring professionals who understand shoreline processes, examining the property yourself, and talking with neighbors who can provide observations on what they have observed over the years, as well as measures they have taken to address erosion on their own properties.
Neighbors sharing observations about erosion that has taken place along the bluff over the years. Photo by Scott Chase
Some of the factors you will want to take into consideration in assessing the property and amount of erosion are included in this checklist from Washington Dept. of Fish and Wildlife:
Prior to hiring a professional, you should research what type of assessments they provide, their expertise with shoreline properties similar to yours, and if their report will include all that you require, or if you’ll need to hire additional professionals. A geotechnical engineer can help determine the amount of erosion that may have occurred over the years, what may have caused that erosion, and the steps you should consider to limit erosion in the future. They may recommend that you hire a landscape designer to help you determine what you should plant to further protect your property. Other professionals who specialize in shoreline properties include coastal engineers, structural engineers, hydrologists, geologists, engineering geologists, arborists, and others. You may only need to hire one, but the challenge is figuring out which one, and what choices you have in your area.
Visiting websites of these professionals can tell you a lot about their past projects and expertise. Talking to others in your community to find out who may have hired a professional and whether they would recommend that person or not could be quite helpful. If a nearby neighbor hired a professional, many of the observations in their report may be applicable to your property as well; ask your neighbor if you could possibly see their report. You may also want to drop into your local planning office, and meet with your county or city planner. They can assist you in finding out what regulations you may need to consider, permits that may be required from other agencies, the timeframe for permitting, and any special studies that may be required. At the end of this newsletter, you’ll find two pages that describe the permitting process for Island County property owners seeking to install soft-shore protection.
NOTE FOR JEFFERSON/CLALLAM:Those two pages were included to give you a general picture, but they are specific to Island County. Check with your own City or County planning departments to find out what is required for you.
Keeping Things Natural
You bought your shoreline property for the spectacular view and access to the water. You know that having a natural looking beach will provide much more satisfaction and maintain property value than having a vertical bulkhead between your house and the beach. And, after professional consultation, you have a better understanding as to whether you require hard armoring (bulkhead) or if you can manage with no armoring or natural-looking soft shore protection, examples of which were described above. What are some of the other steps you can take to ensure additional protection from erosion in the future?
Create a Site Plan
A site plan can be as simple as a diagram you draw yourself, showing key features such as property lines, locations of the house and other structures, septic tank and drainfield locations, driveways and paths, slope, vegetation, and setback distances. Or you can have a professional draw a more complex plan like the one shown below. You should try to site your structures as far back on the property as possible, to protect against future erosion. Vegetation can be planted to not only provide bluff stability and erosion protection, but also to maintain your views. You’ll likely want to work with your contractor and architect for this stage of development.
Determine Your Choice of Shoreline Erosion Protection
The chart below, from the publication “Your Marine Waterfront”, shows cost and complexity considerations for the different methods of shoreline protection. The method you choose, after consultation with professionals, will need to be designed by an engineer who specializes in this field. See the pages on soft shore alternative permitting to get an idea of what will be required of you during the permitting process. Your contractor should be able to help you in this stage.
Plan Drainage to Minimize Erosion
When you remove trees and other vegetation to construct your house, driveways and paths, septic system and drainfield, patios and decks, and other impervious surfaces, rainwater that normally would have been absorbed into the soil now flows off the property, increasing the chances for erosion. There are various ways to control this runoff. Water can be piped over a slope using an engineered tightline system, channeling the water to a diffuser on the beach. Low impact development techniques can be used to infiltrate the runoff into the ground. And vegetation can be employed to absorb the water in the soil and evaporate it into the atmosphere, removing the weight to minimize slide potential. Be sure to consult experts when planning your drainage control.
Use Vegetation for Erosion Control
Appropriate vegetation can not only assist you with your drainage situation, but can also help prevent erosion. Native trees, shrubs and plants, installed on your upper beach area, slope, or in a buffer area at the top of your bluff, can not only reduce erosion, but can provide the stability needed to help prevent some landslides. In some low-energy locations, vegetation may be all that’s required. A 2015 newsletter, based on Guidelines 2 and 5 of the Guide for Shoreline Living, discusses how you can use vegetation to your advantage. To see this newsletter, go to:
When you purchased your already-built coastal home, you likely had it checked by a property inspector who provided you with a written report regarding the structural condition of the house, listing any current or potential problems. This helped you decide whether the house was acceptable in its current condition, whether repairs should be made prior to completing the transaction, or if the house wasn’t what you wanted after all. The potential for near-future repairs, and associated costs, likely had a big part to play in your decision to complete the transaction.
At the same time, did you have the property evaluated for erosion, and what the condition and longevity is for your bulkhead, if you have one? If not, and you have any concerns about future erosion or bluff stability, you might consider having an inspection done soon. Some inspectors are now using “drones” to inspect bluffs and other locations not easily seen from the shoreline or at the top of a bluff. If you find there is any potential for rapid erosion or landslide, you may be able to take appropriate action now. You can also plan corrective measures for the future, which would likely be much less expensive or drastic than just waiting to take action until after a slide or other catastrophic event occurs. It’s possible that simply adding native vegetation or making changes to your drainage can provide an affordable alternative to future problems. Your coastal expert’s report should help guide you as to what you need to consider doing in the future.
Taking Care of Problems
When your family bought the shoreline vacation cabin in the 1980s, the bulkhead showed some amount of deterioration, but still appeared to have a number of years of useful life remaining. A recent walk on the beach, however, may reveal new problems. Maybe you are now thinking that the bulkhead has deteriorated to the point where it may fail in the next big storm or the one after that. You may have already checked with the Planning Department, and found that unless there is an emergency and a threat to your property, getting permits to replace or repair a bulkhead is now quite difficult. What to do? If you, or an expert, determine that you still have a few years left before the bulkhead is no longer functional, now is the perfect time to begin exploring bulkhead alternatives. The first part of this newsletter discussed several of these. Other alternatives can be seen in the following two slide presentations made by the Washington Department of Fish and Wildlife, which have more information than can be covered in this newsletter:
If your property is eroding to the point where you fear losing your house in the near future, you might also consider moving your house further inland. Though this may be seen as a drastic move, it may be less expensive than replacing your failing bulkhead. There are a number of firms in the Puget Sound region who specialize in house moving; some even move homes on barges from one part of the Sound to the other!
Menashe, E., 2004. Shoreline Management and Stabilization Using Vegetation. Greenbelt Consulting, Clinton, Washington. http://greenbeltconsulting.com/ctp.html
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