Credit 1.3: Bulkhead Removal
This credit applies to reduction or removal of any type of hard shore armor (collectively called “bulkheads”).
Bulkheads and shore armor include seawalls, revetments, riprap, gabions and similar along-shore structures designed to protect against wave attack or serve as a retaining wall at the shore. Bulkheads have been constructed on all types of shorelines, but are most common along erodible beaches and non-bedrock bluff sites. The goal of this credit is for complete armor removal, although lower points are awarded for partial removal.
Where this credit applies
This credit applies to any site where bulkheads exist. Bulkhead removal is particularly important at feeder bluff sites where it can restore the natural sediment supply, potentially providing the most benefit to shoreline processes and habitats. Bulkhead removal is also important on beaches where forage fish spawn, because it can help to restore critical habitat in the nearshore and foreshore food web.
Bulkhead removal may not be feasible on small lots with limited space between a house and the shore and no room to move the house back. A qualified professional (coastal geologist or engineer) can advise on the stability of a site and the effect of bulkhead removal prior to considering this action. It may be possible to move part of a bulkhead or move a bulkhead back to restore a partial beach.
When a bulkhead is removed, some form of protection from erosion is often still needed. In these situations, the beach profile is modified using “soft shore protection” measures, in which natural materials (beach gravel, sand, logs, vegetation, etc.) are added to the shore to mimic natural conditions and maintain natural processes.
The point values under this credit take the replacement of hard armoring with a soft shore into account. Therefore, points cannot be earned for both this credit (1.3) and Credit 1.5 “Soft Shore Protection and Enhancement” for the
same length of shoreline, EXCEPT if a bulkhead is removed from a portion of the shoreline (Credit 1.3) and a portion of the previously unprotected shoreline is treated with soft shore methods (Credit 1.5).
This credit offers up to 15 base points plus up to 8 bonus points.
|Net bulkhead removal* along 95-100% of the shoreline||
|Net bulkhead removal* along 75-94% of the shoreline||
|Net bulkhead removal* along 50-74% of the shoreline||
|Net bulkhead removal* along 25-49% of the shoreline||
|Net bulkhead removal* along 10-24% of the shoreline||
|Bulkhead moved back||
|Move bulkhead back along 80-100% of the shoreline so that it is minimum 3 ft (1 m) above OHWM||
|Move bulkhead back along 40-79% of a the-shoreline so that it is minimum 3 ft (1 m) above OHWM||
|Bonus (available once 1 or more base conditions have been met)||
|Do not add beach material or “soft shore” once a bulkhead is removed or moved back, allowing the beach profile to be restored by natural processes||
|Area of bulkhead removal is in a drift cell and/or at a feeder bluff||
|Bulkhead removal is within a shore area with documented spawning habitat for forage fish such as surf smelt, sand lance, etc.||
|Set up and implement a system for monitoring what happens to the beach and property after the bulkhead is removed or moved back.||
* Net bulkhead removal means:
- For a bulkhead that extends the full length of the shoreline, that length removed minus any length that is retained or replaced with armoring. E.g., if 100 ft of seawall is removed and 20 ft is replaced with a riprap revetment, the net bulkhead removal is 80%.
- For a bulkhead that extends along only a portion of the shoreline, the % shoreline along which the bulkhead is removed minus the % shoreline where armoring is retained or replaced. E.g., if a seawall extending along 75 ft of a 100 ft shoreline is removed and none of it is replaced with armoring, the net bulkhead removal is 75%. If 15 ft of the original wall is replaced with riprap, the net bulkhead removal is 75-15 = 60ft or 60% of the shoreline.
How to proceed
Bulkhead removal projects can involve single or multiple properties and can take different approaches, depending on how much of the bulkhead is removed and what is done to the shoreline afterwards. The following explains the Points Available table above.
- Other bonus points: It is also beneficial to coastal habitats to remove or move bulkheads where they had blocked natural erosion and accretion processes (i.e., in a drift cell or below a feeder bluff), and where they occurred next to forage fish habitat.
- However, in some cases, a bulkhead may be removed and the beach profile left to be restored naturally by waves and currents. The upland above the bulkhead may still need to be graded to a more gradual slope, particularly where the bulkhead was originally backfilled; otherwise, the fill could slough into the foreshore and intertidal areas, destroying habitat. However, everything below the OHWM is left alone to allow natural shoreline processes to reshape the beach. The net effect is to re-establish high foreshore and intertidal habitat. If the site characteristics allow it, this can be a more desirable option from a biophysical and ecological perspective, which is reflected in the Bonus Points.
- Adding a soft shore, or not: As mentioned earlier, often when a bulkhead is removed, the beach profile is modified using soft shore protection measures; natural materials (beach gravel, sand, logs, vegetation, etc.) are added to the shore above and below the OHWM to mimic natural processes. This is used when protection from erosion is still needed after a bulkhead is removed.
- Moving a bulkhead back: In some cases, limited lot size may dictate the need for some sort of armoring to protect a home or important infrastructure. In these cases, it may be possible and advantageous to replace a deteriorating bulkhead with a new bulkhead further back from the OHWM. This can allow room for restoring shoreline habitat AND put the bulkhead where it will require much less maintenance or be prone to damage. By moving a bulkhead back, a homeowner can gain a beach with its many amenities as well as re-establish habitat for shoreline flora and fauna (see the following figure).
- Bulkhead removal: Full (100%) bulkhead removal is ideal, but may not always be possible; for example, it may be necessary to retain portions of a bulkhead or keep end walls to tie into adjacent bluffs or bulkheads on neighboring properties. Some shore armor may need to be retained or replaced to protect foundations and underground services. Therefore, points are available for removing a bulkhead from 10% to 100% of the shoreline of a property.Bulkhead removal projects should maximize the restoration of natural processes while balancing the need for property protection. A removal or modification design needs to balance risk of damage to primary structures with the enhancement of shoreline processes and habitat. Full bulkhead removal and enhancement is the goal of these projects, unless geologic or engineering analyses recommend the use of lower impact shore protection at the site.Ongoing maintenanceFinally, note that removing a bulkhead and replacing it with a soft shore (see Credit 1.5) is not a zero-maintenance solution. Any soft shore protection requires maintenance or replenishment in several years, depending on the level of activity of shoreline processes.The Marine Shoreline Design Guidelines (Johannessen et al., 2014 – see full reference below under “For more information”) devotes a chapter to bulkhead removal (Chapter 7, Technique 4). It provides guidance on whether it is appropriate to remove a bulkhead given site conditions, and provides insights on effects, cost, monitoring, and maintenance. While developed for marine shorelines, there are still useful ideas for lake shoreline situations.
Example 2.3.1 Marine and Freshwater: These examples show before and after shots of a bulkhead removal project first on a marine site (top photos MSDG 7.4.7) and on a freshwater site (bottom photos from Taylor).
For more information
Seattle, City of. 2011. Green Shorelines: Bulkhead alternatives for a healthier Lake Washington. 34 pg. Go to http://www.seattle.gov/dpd/ and enter “Green Shorelines” in the search box.
Coastal and Shoreline Management, from Washington Department of Ecology, Shorelands and Environment Assistance website: http://www.ecy.wa.gov/programs/sea/sea-env.htm
Johannessen, J.W. and A.M. MacLennan, 2007. Beaches and bluffs of Puget Sound and the Northern Straits: A valued ecosystem component, US Army Corps of Engineers, Published by WA Sea Grant, Seattle WA. Go to http://pugetsoundnearshore.org/technical_reports.html and scroll down to report 2007-04.
Johannessen, J., A. MacLennan, A. Blue, J. Waggoner, S. Williams, W. Gerstel, R. Barnard, R. Carman, and H. Shipman, 2014. Marine Shoreline Design Guidelines. Washington Department of Fish and Wildlife, Olympia, Washington. 419 p. http://wdfw.wa.gov/publications/01583/
Penttila, D. 2007. Marine Forage Fishes in Puget Sound. Puget Sound Nearshore Partnership Report No.2007-03, Published by Seattle District, U.S. Army Corps of Engineers, Seattle, Washington. Go to http://pugetsoundnearshore.org/technical_reports.html and scroll down to report 2007-03.
Rice, C. A. (2006). Effects of Shoreline Modification on a Northern Puget Sound Beach: Microclimate and Embryo Mortality in Surf Smelt (Hypomesus pretiosus). Estuaries and Coasts, v 29, n 1, p. 63- 71. Go to http://www.sanjuanco.com/index.aspx and search for “Rice shoreline modification”.