Working with Nature to Protect Coastal Properties and Habitats
Coastal shorelines have always been dynamic environments, but they’re getting more so as air and sea temperatures rise.
- Warming oceans lead to expansion of waters. Melting ice sheets and glaciers add to rising seas, with regional increases by 2100 projected to be 2- to 4-feet (0.6-1.2 meters) and perhaps significantly more.
- Warmer ocean waters can fuel more powerful storm systems, bringing intense precipitation events that exacerbate coastal erosion.
Whenever possible, it’s best to let shoreline processes proceed undisturbed. When there are direct threats to property, landowners and communities typically turn to structural hardening or armoring of the shoreline (using jetties, walls, bulkheads or breakwaters). These approaches can protect structures in the short term, but are susceptible to failing. Shoreline hardening can
- disrupt natural processes;
- fragment habitat;
- lower beach levels;
- deflect damage to adjoining shoreline; and
- limit public shore access.
In contrast, living shorelines work with coastal processes. Nature-based techniques represent an increasingly popular approach to stabilizing threatened shorelines in settings with low- to medium-wave energy. Living shorelines can reduce climate impacts while
- conserving soil;
- improving water quality;
- preserving wetlands;
- enhancing wildlife habitat; and
- sustaining property values (by making shorefronts more attractive and more stable).
Living shorelines can also be more affordable than shore-hardening structures. A comparison chart showing relative costs of shoreline stabilization options, prepared by the Massachusetts Coastal Zone Management Office, confirms that all but one of the living shoreline techniques have a “low” construction cost, while costs for rock revetments range from “high” to “very high.” A study in Chesapeake Bay (cited in Natural Defenses from Hurricanes and Floods) found that for every $1 spent constructing vegetative shoreline stabilization, as much as $1.75 returns to the economy in the form of improvements to coastal resources.
Living shorelines are engineered to mimic natural systems. They rely on the capacity of plants to retain soil and withstand waves. Living shorelines typically employ non-structural (or “soft”) approaches tailored to the site, incorporating techniques such as
- marsh plantings;
- low-profile rock sills or dune fencing to protect vegetation; and
- biodegradable materials like coir (coconut fiber) logs or mats.
The Center for Coastal Resources Management and Virginia Institute of Marine Science offer two “decision trees” to help landowners decide which living shoreline techniques most be most effective—whether they already have a defended shoreline or not.
NOAA’s Restoration Center outlines the steps involved in planning and planting a living shoreline project:
- Analyze the site (in terms of erosion, wave energy, prevailing winds, vegetation and soil type);
- Seek necessary permits and comply with local, state and federal shoreline regulations;
- Clear the site of debris, unstable trees and any previous hardening materials that have failed;
- Install the new vegetation or biodegradable materials such as natural fiber mats or logs (made of coir, jute or straw);
- Continue to monitor and maintain the new living shoreline.
Guidance offered by the State of Massachusetts for coastal landowners may be helpful for those throughout the region who are considering shoreline projects:
A landscape architect, biologist, engineer, or other environmental professional with experience designing, permitting, implementing, and successfully maintaining bioengineering projects in coastal areas should be consulted to:
- identify regulatory requirements that must be addressed and ensure the project fully conforms with those requirements;
- determine the conditions at the site, such as the history of erosion, exposure to wind and waves, soil types, and runoff patterns that will affect the choice of materials for the site;
- identify any existing conditions including over-steepened slopes and the presence of invasive species that must be considered as part of the design;
- identify the appropriate natural fiber blanket and vegetation for the site conditions;
- identify the volume and composition of fill, if needed;
- identify the best time of year to install the various components of the project; 7) develop an access plan if any heavy equipment is needed;
- prepare plans for and oversee permitting; and
- prepare design specifications for and oversee construction. It is also recommended that the consultant be involved in the monitoring and maintenance of these projects.
While Living Shorelines represent one tool for combating climate impacts along the shore, it is important for communities to consider other management techniques such as coastal setbacks; retreat and relocation; zoning codes and land use regulations. More adaptation guidance can be found in the resources listed in the Climate Network’s Community Toolkit and in the appendices of the Climate Network’s report Municipal Climate Change around the Bay of Fundy.
A 2014 conference in New Hampshire produced a glossary of common definitions to help navigate the many terms employed in discussions of shoreline stabilization.
Coastal Shoreline Continuum Ideal & Living Shoreline Treatments (courtesy of Burke Environmental Associates)
Living Shoreline Resources
Massachusetts StormSmart Coasts—StormSmart Properties (MA Office of Energy and Environmental Affairs) has a series of detailed (6- to 10-page) factsheets on topics related to living shorelines:
- Landscaping to Protect Your Coastal Property from Storm Damage & Flooding
- Artificial Dunes and Dune Nourishment
- Controlling Overland Runoff to Reduce Coastal Erosion
- Planting Vegetation to Reduce Erosion and Storm Damage
- Bioengineering—Coir Rolls on Coastal Banks
- Bioengineering—Natural Fiber Blankets on Coastal Banks
- Sand Fencing
Natural Defenses from Hurricanes and Floods (National Wildlife Federation)
Shore Zone Characterization for Climate Change Adaptation in the Bay of Fundy (Atlantic Climate Adaptation Solutions Association)
Climate Change and Shoreline Protection (Atlantic Climate Adaptation Solutions Association)
Living Shorelines: Impacts of Erosion Control Strategies on Coastal Habitats (Atlantic States Marine Fisheries Commission)
- Shoreline Stabilization Techniques
- Plant-focused Bioengineering Approaches for Dynamic Coastal Wetlands
Living Shorelines Workshop, Ecology Action Centre, NS (March 2013)
- Tools for Assessing Coastal Vulnerability
- Natural Coastal Adaptation to Physical Change/a>
- Vulnerability Assessment for Shorelines in Nova Scotia
- Managing Coastal Erosion on the Northumberland Strait
- Coastline Change Detection Utilizing Ground-Based Laser Scanning
- Living Shorelines Principles and Practices
- Living Shoreline Practices
- Living Shorelines Kingsburg
- Monitoring the Northumberland Shoreline in a Changing Climate
Living Shorelines Videos and other resources are available from the Ecology Action Centre’s Living Shorelines Toolkit.
Information on Native Shoreline Plants
Native Salt Marsh Plants and Animals, Cape Cod National Seashore
Massachusetts Coastal Zone Management Office’s Coastal Landscaping Plant List
Most options for addressing coastal erosion, storm damage, and flooding are likely to require a permit under the Massachusetts Wetlands Protection Act through the local Conservation Commission. Additional permits may be needed from the Massachusetts Department of Environmental Protection (MassDEP) Waterways Program and the U.S. Army Corps of Engineers if the project footprint extends below the mean high water line or seaward of the reach of the highest high tide of the year, respectively. Often, Conservation Commission staff members are available to meet with applicants to go over the important considerations. To learn more, visit the state’s wetlands protection web pages and the state’s webpage on permits for coastal landscaping
This New Hampshire Shoreland Program presentation describes state permitting requirements affecting coastal zone projects.
Mandatory shoreland zoning information can be found on the Maine Department of Environmental Protection website.
US Permitting Contacts
US Army Corps’ Regulatory Jurisdiction (This presentation outlines UACE jurisdiction)
New Brunswick requires a permit for watercourse and wetland alterations through the New Brunswick Department of Environment and Local Government.
All land above the high-water line is considered private and no permitting is required. In Nova Scotia, regulatory approval for structures on Crown lands between the high- and low-water mark (e.g., construction of rock walls or wharves) is needed from the Department of Natural Resources under the “Foreshores Act.” Moving of sediment or construction on protected beaches also needs a permit from DNR under the Beaches Act. If alterations to watercourses or wetlands are proposed, applicants should contact Nova Scotia Environment.
- Precipitation from extreme events in the GOM region has increased 74 percent since 1958 (NOAA).
- Extreme weather already poses economic and ecological challenges, and these events are expected to grow more frequent in coming decades, with precipitation increasing 5-9 percent (IPCC 2013).
- By 2050, climate scientists project a more rapid increase of 2.5 to 3.5°C (4.5 to 6.3° F) in regional air temperature (IPCC 2013).
- Temperatures in the Gulf of Maine have risen much more in recent decades than many other coastal waters around the world, and a 2012 “heat wave” in sea surface temperatures had damaging economic impacts.
What’s Climate Change and What’s Just the Weather?
This one-minute animation by Ole Christoffer Haga, produced by Teddy TV for the Norwegian Broadcasting Corporation, clearly and humorously illustrates the difference between long-term climate trends and variable weather patterns.