Peter Ruggiero, Department of Geosciences, Oregon State University
The shores of Puget Sound are rapidly being hardened and covered with artificial structures. While shoreline armoring often succeeds in protecting upland investments, shoreline armoring activities are hypothesized to represent a significant source of nearshore morphodynamic and marine habitat modification in Puget Sound.
Shoreline armoring is believed to affect physical processes in many ways, primarily by causing beach narrowing, sediment coarsening, and a decrease in the natural sediment supply from eroding bluffs. Shoreline armoring is also thought to affect biological processes through loss of upper intertidal habitat, changes in sediment composition, and decreased organic input.
However, it has not been confirmed in the field or the laboratory whether currents and sediment transport rates will increase or decrease in front of a hardened shoreline, as compared to a non-armored section of beach, and whether the sedimentary environment will be significantly modified.
California (1986-1994) : ‘A comparison of summer and winter beach profiles on beaches with seawalls and on adjacent control beaches show no significant long term effects or impacts of seawalls during this seven year period.’ (Griggs and co-workers early 90’s)
Virginia (1980-1992): ‘The results at three time scales (storm seasonal and interannual) and from the three analysis methods all supported the same conclusion, namely: the volume erosion rates are not higher in front of seawalls.’ (Basco and co- workers mid 90’s)
Oregon (1986-1998): ‘Ten years of monitoring has revealed that the structures at these seven sites are having no adverse impacts on the surrounding beach or adjacent properties.’ (Hearon and McDougal, 1996)
Dr. Ruggiero’s comments are quoted from the U.S. Geological Survey website and a May 11-14 conference on shoreline armoring.
President Obama says real science not political agendas should govern policy. One wonders why Governor Gregoir rejects this opinion and relies instead on speculation as the foundation for environmental action.
See our previous article: Does science justify bulkhead rules?
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Peter Ruggiero is an Assistant Professor in the Department of Geosciences at Oregon State University. His current research interests include applied coastal geomorphology and developing methodologies for assessing vulnerability to coastal hazards particularly in light of a changing and variable climate. Dr. Ruggiero earned a bachelors degree in Civil Engineering from Lehigh University in 1991 and a Ph.D. in Coastal Engineering from Oregon State University in 1997.
Following his graduate work, he worked for the state of Washington as a principal investigator of the Southwest Washington Coastal Erosion Study. This multi-year effort developed a quantitative understanding of the regional sediment dynamics of the Columbia River littoral cell.
Ruggiero then worked for the US Geological Survey in Menlo Park, CA between 2001 and 2005 getting involved in coastal studies in Alaska, North Carolina, and Sumatra. Since 2006, he has been at Oregon State University focusing on a variety of projects quantifying and assessing the vulnerability of communities to coastal hazards.
The poster of this information has isolated a single author’s presentation from among many (More than 30 of the 38 attendees) during the Shoreline Armoring on Puget Sound Workshop conducted May 12-14th, 2009. I award one star – proportionate to the information it conveys relative to the rest of the information available on the referenced site.
I have personally, albeit casually, observed various approaches to beach armoring including above, at, and below mean high tide ranges along exposed and protected shorelines on Bainbridge. I have observed 100-year and annual storms along natural and armored beaches on Bainbridge. And I have observed the various wakes from naval warships, large and small commercial vessels, ferries and passenger-only fast ferries before congestion and wake effects at higher tides resulted in a USCG Puget Sound Vessel Traffic System and various speed limits. I believe that shoreline armoring has numerous in situ and sometimes broader effects both landward and seaward. Most of the presenters at the May 12-14 symposium seem to suggest the same conclusion, although many statements when taken out of context might suggest otherwise.
In an earlier comment I suggested shoreline homeowners review the papers which were presented rather than rely on single exerpts presented to advocate a particular viewpoint or agenda.
The abstracts and presentations of the others may be found at http://wa.water.usgs.gov/SAW/abstracts.html#jackson
If you are a property owner on or user of any fresh or saltwater shoreline anywhere in the world, please take the time to educate yourself further by reviewing all the linked presentations and their images, tables and graphs. I believe you may then have a more comprehensive understanding of and respect for what is known, suspected, and yet to be determined regarding armoring and its impacts; and you may recognize and be able to use many of the important concepts and terms in any future discourse on the topic.
And ask your City Council representative to read these links and report to you to that effect when he or she finishes. For they also need to be familiar with the information to represent us properly and fairly as the debate continues to heat up.
Unfortunately, any single presentation considered alone, no matter how authoritative or “scientifically” extant at least regarding the locale and methodology of focus, tends to oversimplify the complex dynamics of the broad issues of shoreline armoring and serves to obscure pertinent possibilities and important considerations from public scrutiny and discourse.
For example, this particular presenter cited above supports his own isolated conclusions with isolated findings from studies in California, Virginia, and Oregon in the nineties.
Other, equally impressively credentialed presenters at this forum offered alternative findings from other, more recent and ongoing studies in
California(http://wa.water.usgs.gov/SAW/presentations/hubbard.pdf), Delaware ( http://wa.water.usgs.gov/SAW/presentations/jackson.pdf ) several in California, and Puget Sound itself e.g.,
( http://wa.water.usgs.gov/SAW/presentations/rice.pdf ) and
( http://wa.water.usgs.gov/SAW/presentations/toft.pdf ).
As co-inhabitant riparian stewards of a unique and finite Puget Sound where misunderstood or poorly researched choices have been implemented in the past, we shoreline homeowners should assume some responsibility to moving forward with some caution now that some spokespeople are beginning to establish and challenge various “hypotheses”.
More than a few presenters seem to suggest that all may neither be as simplistic nor obvious as it appears and they justify this reasoned and unselfish approach with some of the representative comments I include below. I hope those who have not taken the time at least to read the abstracts of the papers will find the following abstract extracts sufficiently provocative that you follow up with the entire body of work and begin to question the “Scientific Method” which supports anything presented or discounted as “science”
“Together these studies demonstrate that human alterations of Puget Sound shorelines dramatically affect abiotic attributes and can adversely affect the biota; these studies also point the way towards more expanded, systematic field studies to improve our understanding and management of the biological effects of altered Puget Sound shorelines.” Casey Rice, NOAA/NWFSC
Mukilteo Research Station
“Results indicate that various habitat types can affect fish and invertebrate abundance and compositions, as well as fish behavior and feeding patterns. Understanding such linkages is vital to planning rehabilitation efforts along degraded portions of Puget Sound, and will help guide the restoration of salmon habitat.” Jason Toft, Jeffery Cordell, Sarah Heerhartz, Beth Armbrust, and Charles Simenstad School of Aquatic and Fishery Sciences, University of Washington
“Protecting and restoring the Puget Sound ecosystem, given changes associated with sea level rise, constitute profound management and policy challenges.” Kirk L. Krueger, Kenneth B. Pierce, Jr., Timothy Quinn, and Dan Penttila
Habitat Program, Washington Department of Fish and Wildlife, Olympia, WA 98501
“The effect of seawalls on beaches has been found to be most sensitive to the position of the seawall within the surf zone, the beach slope, and the reflection coefficient. This talk will describe a conceptual model of seawall impacts on sediment dynamics and suggest pilot investigations specific to the Puget Sound consisting of beach monitoring, field experiments, and modeling efforts.” Peter Ruggiero, Department of Geosciences
Oregon State University (Yes, the identical authority cited in the original post above)
“The findings of both the field observations and the modeling point to the need for including an accurate description of grain composition in modeling mixed sand and gravel beach response and the need for long-term observations of both forcing and response.” Phil Osborne, Greg Curtiss, Golder Associates Inc. Redmond,Wa and Neil Macdonald, Coldwater Consulting Ottawa, On
“As unmodified bluffs in the study area continue to gradually recede through erosion and landsliding, there will likely be a continued desire for landowners to build bulkheads. If carried out, this would lead to further sediment impoundment and further reduction of the natural sediment input to the nearshore system, as well as site-specific habitat impacts. The possibility of further decreasing sediment supply volumes for net shore-drift cells, along with the lag time of impacts from past modifications, would likely lead to substantially-increased, negative, cumulative impacts to nearshore habitats. Restoration and conservation efforts should proceed with this in mind.
Management of developed shores in King County needs to be a balance of minimizing additional long-term negative impacts to beaches and nearshore habitats by preserving/restoring sediment source inputs while also addressing the clearly demonstrated needs of landowners.. …” Jim Johannessen, LEG & MS, Coastal Geologic Services Inc.
” Proposals for additional shoreline armoring have been accompanied by an increased concern by both the California Coastal Commission as well as a number of environmental organizations with the cumulative impacts of these structures. The potential impacts of armoring the coastline include 1] visual effects, 2] impoundment or placement losses, 3] reduction of beach access, 4] loss of sand supply, 5] impacts on surfing, 6] passive erosion, and 7] active erosion. These potential impacts will vary from site to site and with different types of structures. It is the objective of the environmental impact assessment process to evaluate each of impacts in order to determine their significance and whether or not they can be mitigated.” Gary Griggs,Director-Institute of Marine Sciences (and) Professor of Earth and Planetary Sciences
University of California Santa Cruz
“The multi-year monitoring program will consist of 1) topographic profiles to determine sediment losses through time; 2) dyed sand tracer studies to determine pathways of sediment transport; 3) streamer traps to quantify rates of transport; 4) current meters and pressure transducers to provide process data; and 5) optical backscatters and current meters placed offshore to determine rate of delivery of sediment to the navigation channel.” Karl F. Nordstrom Ph.D, Rutgers Univ, Nancy L. Jackson, New Jersey Institute of Technology, and Patricia Rafferty, U.S. National Park Service
Dr Nordstrom’s Current position
Professor, Institute of Marine and Coastal Sciences, Rutgers University.
Visiting Positions
Geography Institute, University of Greifswald, Germany.
Dept. of Territorial Studies and Planning, Polytech. of Turin, Italy.
Marine Institute, Universidade do Vale do Itajaí, Brazil (Instructor of short course)
Department of Geography, University of Western Australia.
Department of Geography and Soil Science, Univ. Amsterdam.
Geography Institute, University of Kiel, Germany.
Geography Department, University of California, Los Angeles.
“The SMA establishes a system of permitting for shoreline development. Substantial development permits are needed for many projects costing over $5,718, or those interfering with the public’s use of the waters. Many common shoreline uses are exempt from obtaining a substantial development permit, including bulkheads necessary to protect existing single family residences.
Even if a bulkhead project meets the criteria for exemption, it must still comply with the SMA and all applicable regulations and design standards contained in the local SMP. The local SMP may require conditional use permits for bulkheads, soft approaches as an alternative to hard armoring, or may prohibit bulkheads.” Randy Carman, Washington Department of Fish and Wildlife and Kathy Taylor, Washington Department of Ecology
“Shorelines in Puget Sound are diverse in terms of their geomorphology and their biotic communities. The long coastline of this estuary consists of a large proportion of linear, relatively open shorelines plus small to large embayments and a number of large river deltas. Bedrock shorelines are quite uncommon in the Sound proper. As in all marine systems, the biota are very closely linked to the energy level (waves or currents) and the substrate type. The linear shorelines, which include most of the armored areas, can be characterized as muddy, sandy, or pebble-cobble. Many beaches have pebble and sand in the mid and upper shore regardless of the low-shore substrate; these upper-shore areas are physically unstable and biologically relatively depauperate, with sparse populations of worms and crustacea. Areas at or above Ordinary High Water, however, are important for talitrid amphipods (important decomposers and food for shorebirds) and as spawning habitat for several species of forage fishes that are central to Puget Sound food webs. Muddy beaches (which range from extremely soft and anoxic muds to firmer sandy mud) are often dominated by burrowing mud shrimp or ghost shrimp, which aerate but further soften the sediment with their extensive tube systems. Other common occupants of mud are deposit-feeding clams (Macoma spp.), some polychaetes (especially spionids and capitellids), and some amphipod crustaceans (especially corophiids). Eelgrass (Zostera marina) is found in sandier areas. Moderate-energy sand beaches may have extensive eelgrass beds. Certain beaches in Puget Sound without eelgrass have beds of sand dollars, which primarily live subtidally but extend up into the low shore; when present, they tend to be very dense and exclude other biota via bioturbation. Areas without eelgrass or sand dollars, especially those with more wave action, have sparse clam populations (including horse clams and cockles), and a different array of sparse polychaete species than in mud. Commercially valuable geoduck clams can be found naturally or cultured on sandy shorelines. In areas where cobbles are found on the low shore, the substrate is stabilized into a complex and diverse mix of cobbles, pebbles, and sand; these habitats harbor a rich flora (on the cobbles) and fauna (both on the cobbles and infauna). Recreationally and commercially harvested clam species (mostly hardshell clams) are abundant in this habitat type, as is a rich assemblage of polychaetes (many families) and crustacea, including Cancer crabs, other crabs, amphipods, and isopods.
Puget Sound beaches provide key linkages between terrestrial and marine food webs. A variety of birds use the beaches, include Great Blue Heron, gulls, Dunlin, and other shorebirds. On unaltered shorelines, overhanging vegetation drops both detritus and insects onto the shore, linking to detritus-based food webs (via decomposer amphipods) and to fishes such as juvenile salmon that forage on the shore at high tide. Other animals from nearshore waters probably use the beach at high tide, although these linkages have had little documentation. Nearshore waters are critical to the beach, in turn, by bringing food for the abundant suspension feeders, as well as larvae, spores, and seeds of shoreline organisms, nearly all of which have dispersive propagules. Humans use the shore extensively, for both extractive (harvesting of clams and other shellfish, as well as algae) and non-extractive (birdwatching, walking) purposes.” Megan N. Dethier, University of Washington, Biology Dept. and Friday Harbor Laboratories
“Seawalls and bulkheads are widespread on Puget Sound. The high value of coastal property and the relatively modest wave environment make armoring both desirable and practical. Residential-scale armoring typically involves the construction of rock, timber, or concrete seawalls, with riprap revetments more common in industrial settings. Currently, approximately one third of Puget Sound’s shoreline is armored, although the proportion varies regionally due to differences in geology and development patterns.
Concerns about the potential impacts of armoring have increased in recent years, in part due to a greater awareness of the role of beaches and riparian zones in the greater Puget Sound ecosystem. Possible impacts associated with seawalls and bulkheads include burial and modification of back beach areas, changes in both the delivery and the transport of beach sediment within the littoral system, beach erosion or shifts in substrate size due to wave interactions with structures, loss of ecological connectivity between terrestrial and aquatic environments, and long-term loss of the upper beach due to passive erosion. These concerns have led to increased scrutiny of armoring proposals and growing interest in alternative technologies, including beach nourishment and hybrid structures employing large wood.” Hugh Shipman (WA Dept of Ecology)
“The National Research Council report, Mitigating Shore Erosion Along Sheltered Coasts, examines the impacts of shoreline management on sheltered coastal environments (e.g. estuaries, bays, lagoons, mud flats, deltaic coasts) and identifies conventional and alternative strategies to minimize potential negative impacts to adjacent or nearby coastal resources. These impacts include: loss of intertidal and shallow water ecosystems, effects on species, and loss of public trust uses. The study provides a framework for collaboration between different levels of government, conservancies, and property owners to aid in making decisions regarding the most appropriate alternatives for shoreline protection. The report considers how design criteria, the mix of technologies employed, and land use plans could be implemented for the protection of the environment and property over the long term given current trends in erosion and inundation rates and a possible acceleration of relative sea-level rise. The report concludes that although loss of small parcels of shoreline habitat from hardening may not have a large impact on the ecosystem, the cumulative impact of the loss of many small parcels will at some point, alter the properties, composition, and values of the ecosystem.” Susan Roberts, Ph.D., Ocean Studies Board, National Research Council, The National Academies
“Human relationships with the natural environment are exceedingly complex. Commonly referred to quality-of-life definitions incorporate aspects of culture, lifestyle, personal health, and family and social relationships as well as people’s “relationship to salient features of their environment”. Ecosystems have both intrinsic and instrumental value to humans and activity that extracts direct social and economic benefits from nature may do so at the cost of unintended degradation of ecosystem services. From this perspective, the task of management is to strike a balance that maintains or restores sustainability, with restoration one of numerous available tools. Seawalls and other engineered features of occupied shorelines embody many contradictory aspects of the human relationship with nature. In that they prevent erosion or wave attack, and create or protect agricultural lands or areas of human habitation, they are generally regarded as making positive contributions to ecosystem goods and services. Improved scientific understanding reveals numerous tradeoffs across ecosystem functions, goods and services associated with the extensive armoring of Puget Sound shores, in association with altered patterns of sediment delivery to nearshore ecosystems. We have little understanding of how people in the region view such tradeoffs however. Dialogue with public stakeholders can enlarge understanding of the roles that removal of shoreline armoring can play in a restored Puget Sound ecosystem in which humans are considered to be integral elements. So can empirical social research.” Thomas M. Leschine, Ph.D, Director and Professor at School of Marine Affairs, University of Washington
“Shoreline stabilization efforts incorporating salt marshes, with or without additional hardened structures, are known as ‘living shorelines’, and several states have adopted specific permitting guidelines in an effort to promote this approach. Evaluation of ‘living shoreline’ projects is preliminary, but suggests that project design and success can vary significantly with site conditions.” Carolyn Currin, Ph.D, NOAA Center for Coastal Fisheries and Habitat Research, Beaufort, NC
“Shoreline armoring in Washington State is managed by local, state, and federal agencies, although many shoreline armoring project occur outside of federal jurisdiction. The Washington State Shoreline Management Act (RCW 90.58; WAC 173-26; WAC 173-27) establishes a joint management scheme between local governments and the State Department of Ecology, but shoreline armoring permits are usually administered through a process that occurs purely at the local government level with few shoreline armoring permits being directly reviewed by Ecology. Therefore, the State Department of Fish and Wildlife and local governments are the primary agencies directly managing shoreline armoring, but administer completely different sets of statutes and rules. This presentation will provide a brief overview of the shoreline management scheme in Washington and summarize limitations within that management scheme. Local government experience with managing new shoreline armoring, repair and maintenance of existing shoreline armoring, and removal of shoreline armoring during restoration projects will be used to highlight information and data needed by local governments to better manage shoreline armoring.” Peter Namtvedt Best (City of Bainbridge Island)
I include this abstract last because it represents an appeal in behalf of us all to the political governing authorities and the scientific community to develop and provide clear consensus and direction to those who must interpret and enforce policy at the property owner level. I applaud Mr Best’s dedicated service to our community and I seriously regret his recent decision to resign. He has attempted to be an advocate for all users of our riparian divide despite woefully poor resources and lacking support from the various agencies which demanded he learn their regulations and policies and impose or enforce them upon our growing-out-of-control community. We have lost an increasingly knowledgeable and influential voice amongst myriad special interests and stop-gap regulators who are all attempting to find consensus among common interests while the earth patiently reveals what might ultimately be considered acceptable and undeniable “science” one human observation at a time.
j nute
Thanks, j nute.
We posted the excerpt from a single presentation at the workshop because it clearly stated the problem. Not enough science has been done to show that armoring causes any real harm. Puget Sound Partnership wants to spend $300 million per biennium to restore Puget Sound, but only 1.5% of that would be set aside for scientific research. Too little science has been done here. Our state should be doing more.
In citing the “precautionary principle”, policy makers say they suspect that harm is being done, or that the “cumulative effect” of human actions may cause harm. Therefore, they must take action to prevent the harm. This seems logical, but the environment is a complex system and the behavior of complex systems is, well, complex.
Testing on the management of complex systems by humans shows that we rarely achieve our preferred result and often fail in a spectacular fashion. Fortunately, the testing has been done on computer models that can be rebooted without actually doing irreparable harm.
We posted the excerpt and provided links to all of the workshop presentation materials. We’re thankful that you have followed the links and hope others will do the same. Each, then, will draw his own conclusions.
Thank you, j nute. I couldn’t have said it better.