Coastal Wetlands

Salt marshes, freshwater tidal marshes, tidal flats, inlets, and coastal streams, rivers, and ponds are vulnerable to flooding and erosion. Just like on the open coast, the boundary between coastal wetlands and adjacent uplands is not static, and changes in response to daily and annual high tides, storm events, and sea-level rise. Wetlands and river banks buffer upland environments from storm damage and flooding. Wetlands protect water supplies and provide habitat for fish and wildlife, including commercially important fish species. Learn more about Maine's coastal wetlands or find out if your property contains or is near wetlands.

NOTE: Maine classifies all areas below the highest annual tide elevation, including rocky shores, sand beaches, mud flats, and salt marshes, as "Coastal Wetlands." In order to facilitate problem solving on this website, Coastal Wetland types have been grouped into three categories: Beaches & Dunes; Bluffs & Rocky Shores; and Coastal Wetlands.

Checklist to ID coastal hazards on your property                                                                            A checklist has been developed to help you identify and rank beach and dune hazards, using the maps and other resources in this guide and by conducting a field inventory of your property.

 Download the Coastal Wetlands Checklist - 131KB

Coastal Wetlands Hazard Actions at a Glance

 

My property floods often and the wetland boundaries are changing. What can I do?

Speak early and often to town officials and state agency staff.

Weigh the risks, with help from a certified geologist, licensed engineer, or other professional.

Finally, consider your options for taking action:

Learn more about coastal wetlands

The Maine coast contains approximately 19,500 acres of wetland, more than any other New England state, New York, or Canadian province in the Gulf of Maine. Marsh types vary along the coast due to different geology and tidal ranges, from extensive back-barrier marshes in southern Maine to river-fringing tidal marshes and pocket wetlands in central and eastern Maine.

Much of the information in this section is from the extremely comprehensive guide, Maine Citizen’s Guide to Evaluating, Restoring, and Managing Tidal Marshes. Other sources for information on Maine’s salt marshes include Maine Salt Marshes: Their Function, Values, and Restoration and Salt Marshes in the Gulf of Maine, Human Impacts, Habitat Restoration and Long-Term Change Analysis.

How coastal wetlands work & the benefits they provide

Wetlands are part of what makes the Maine coast beautiful and attractive to residents and tourists alike. And they provide a variety of valuable and related ecological and societal benefits:

 

Shoreline anchoring: Coastal wetlands “anchor” barrier beaches and sand dunesto the mainland. As new sediment washes into the marsh with each tide, the marsh surface maintains elevation as sea level rises.

Storm surge protection: Coastal wetlands slow wind-driven waves, and help to protect uplands from erosion during storm-related coastal flooding.

Pollutant buffering: By trapping sediments and filtering water, marshes prevent pollution from reaching surface and ground water.

Vital habitat: Many species of birds, fish, and other wildlife use salt marshes for food and shelter. Marshes provide nursery and breeding habitat for commercially valuable fish and shellfish.

Recreational uses: Coastal wetlands support activities such as hunting, fishing, birdwatching, clamming, etc.

Marsh System Types

Marsh systems in Maine can generally be classified into three different types based on their overall geomorphology and shape. 

Back-Barrier Marshes Finger Marshes Fringe Marshes

  Located adjacent to barrier beaches, with direct access to the ocean through tidal inlets. Usually dominated by high marsh.

Long marshes along tidal channels. The area of high marsh is large compared to size of the channel.

Marshes on the edges of protected shorelines in estuarine coves and rivers, or at the toe of eroding bluffs. With less area of high marsh and bordered by mud flats, fringe marshes are strongly influenced by erosion from ice and waves.

 

Vegetation Zones

A typical coastal wetland in Maine has several different zones of vegetation based on the tides.

Low marsh, between mean low tide and mean high tide, is flooded twice daily by tidal action.

High marsh is flooded by above-average tides twice a month and irregularly by storm tides.

Pannes are shallow “ponds” in the high marsh that are flooded periodically by high tides. Deeper pannes that remain filled with water (pools) may contain widgeon grass (Ruppia maritima), sheepshead minnow, and mummichogs, providing a source of food for waterfowl.

Tidal channels, open water, and tidal flats are all important components of the marsh ecosystem. Tidal flats may support economically significant marine worm and clam populations.

Flooding and erosion of Maine's coastal wetlands

Property on and adjacent to coastal wetlands usually floods during the annual high tide, during heavy rains or spring snowmelt, or during periods of storm surge. These areas, from a regulatory standpoint, are part of a coastal wetland since they are at or below the reach of the tides. Coastal property flooding problems may be chronic, with regular inundation by high tides or minimal storm surges. Flooding may be less frequent and occur only in larger storm events and high storm surges.

Erosion of marsh surfaces can be caused by:

Sea-level rise. Coastal wetlands persist when sediment is delivered to the marsh surface at the same pace as sea-level rise, which has been fairly steady over the last century. However, if sea-level rise accelerates and sedimentation rates cannot keep up, marsh loss could occur.

Tidal currents. At high speeds, ebbing and flooding tidal currents can erode marsh surfaces, especially along the edges and outer banks where a tidal channel bends.

Wind-driven waves. Waves, especially those associated with storms, can erode marsh surfaces at high tide. At lower tides, waves can erode marsh banks along tidal channels. This relates to the aspect (or direction) that a marsh faces and the fetch (distance) that the wind can blow over the water. A longer fetch will allow larger waves to form. Typically in Maine, marsh surfaces or channels that face northeast are most susceptible to erosion.

Boat wakes. Motorboat wakes can cause abnormally large waves to erode the edges of the marsh. 

Foot traffic. In some areas, traditional public access has cut across marsh surfaces to access fishing or recreational locations. Heavy foot-traffic on marsh surfaces, even for a short amount of time, can damage marsh vegetation and erode the surface of the marsh.

Ice floes. Winter high tides can lift frozen blocks of ice, mud, and plants off the marsh and expose the underlying surface to additional erosion. In other instances, ice floes actually transport sediment from one area of the marsh to another.

How do I know if coastal wetlands are a part of my property or neighborhood?

Section 4 of the Maine Citizens Tidal Marsh Guide provides an outline of characteristics that can help you identify coastal wetlands as well as the different values and services that a wetland may provide.

The National Wetland Inventory Maps created by the US Fish and Wildlife Service identify large areas of coastal wetlands, although they were created using 1980s aerial photographs, so existing marsh conditions may be different than those mapped.

Expect boundaries to change. The nature and location of coastal wetlands may change in the future with changing elevation of the highest annual tide due to sea-level rise. (See the Maine Geological Survey mapping efforts for sea-level rise in southern Maine.)

The Maine Geological Survey has simulated the potential impacts of sea-level rise on the coastal wetland boundary for the Drakes Island and Wells Beach, Wells area. Additional online reports and maps for coastal communities in southern Maine will be available in the future. Wetland information is also available from resources on the Maps & Data page.

How do I know if wetlands are vulnerable to flooding and erosion?

Once you have identified the presence, absence, type, and extent of coastal wetlands on or adjacent to your property, use the Coastal Wetland and Coastal Flooding Checklist to evaluate the hazards posed to and by the wetlands. Think about how existing wetlands, and their associated hazards like erosion and flooding, may respond to sea-level rise or increased storm events.

Download Coastal Wetland & Coastal Flooding checklist - 43KB

Classify the level of risk associated with each hazard. That is, if tidal marsh or bank erosion is occurring, at what rate in the short term? The long term? How close is your structure to the highest annual tide?

Consider having a professional geologist, licensed geotechnical engineer, or coastal floodplain expert investigate your property to help you further classify the risk associated with identified hazards, including erosion and coastal flooding.
 

 

Do nothing

The erosion of coastal wetlands along the shoreline is, to a large degree, a natural process that has been occurring over a long period of time, shaping and reshaping the coastal environment. For this reason, doing nothing to address erosion is an option that should be considered. If the erosion is natural and not causing an immediate hazard to property, structures, or infrastructure, doing nothing is usually the least costly and environmentally preferable option.

In evaluating the “do-nothing” alternative, assess the level of risk you are willing to accept in conjunction with the existing and expected uses of the property. The “do nothing” alternative makes the most sense if:

  • there aren’t any structures on your property,
  • the property is in areas of critical habitat,
  • or in areas where erosion is minimal and a structure is located far away from the wetland.
     

Expect wetland boundaries to change. The nature and location of coastal wetlands may change in the future with increasing elevation of the highest annual tide due to sea-level rise. (See the Maine Geological Survey mapping efforts for sea-level rise in southern Maine.)

The steps below will help you decide if the “do-nothing” alternative makes sense for your property.

1) Contact local, state and/or federal regulatory officials. Individuals experienced with coastal regulations may not need to consult officials in all cases; however, if in doubt seek regulatory advice before proceeding with a project.

2) Obtain an environmental assessment from a certified engineer or other qualified professional with expertise in coastal geology and biology. In most cases local, state, and/or federal regulators can help direct you to the best professional discipline to assist with your specific project. Sometimes it is helpful to have the consultant completing the environmental assessment and the construction contractor present at regulatory consultation meetings.

3) Evaluate your risk. Check your insurance coverage to make sure you have adequate liability coverage related to loss due to shoreline erosion or flooding, as well as flood insurance through the National Flood Insurance Program.

Move back to avoid the hazard

Avoiding wetlands and their associated hazards as much as possible is usually the most efficient and cost effective response, especially when siting new development.

One of the most effective ways to ensure safety of an existing structure that is being threatened by erosion or flooding is to relocate the structure out of the hazardous area. Although moving back can be very effective in minimizing the hazard, it can be expensive. Costs vary from several thousand dollars to tens of thousands of dollars, and are based on the existing foundation of the structure, size of the structure, topography and geology, and distance the structure may need to be moved. Relocation of a structure can also be constrained by the size of a property and any applicable setbacks, such as from other existing structures, lot boundaries, or roadways.

When planning new development, review the Flood Insurance Rate Map for your proximity to a flood zone. It is easier to site new development away from the flood zone than to mitigate or rebuild later. If you are moving a structure, consider also elevating the structure at the same time. The National Flood Insurance Program insurance rates increase for a structure in a flood zone, but decrease if the structure is elevated. Contact the Maine Floodplain Management Programfor guidance.

As much as is practical with your building considerations, consider moving back to avoid some hazards. Consideration should also be given to significant habitat resources or environmentally sensitive areas, which are usually identified by municipal or state regulations.

Follow the steps below to gain the environmental and regulatory information needed for decision making. The steps are listed in general order although some steps may be conducted concurrently.

1) Contact local, state and/or federal regulatory officials. Individuals experienced with coastal regulations may not need to consult officials in all cases; however, if in doubt seek regulatory advice before proceeding with a project.

2) Obtain an environmental assessment from a certified engineer or other qualified professional with expertise in coastal geology and flood hazards. In most cases local, state, and/or federal regulators can help direct you to the best professional discipline to assist with your specific project. Sometimes it is helpful to have the consultant completing the environmental assessment and the construction contractor present at regulatory consultation meetings.

3) Evaluate your risk. Check your insurance coverage to make sure you have adequate liability coverage related to loss due to shoreline erosion or flooding, as well as flood insurance through the National Flood Insurance Program.

4) Develop a mitigation plan if professional and regulatory consultations result in a recommendation that you move structures to address coastal erosion or flooding concerns.

5) Be Neighborly. If the plan involves work at or near a property boundary, or if moving a structure may affect an abutter’s “viewshed,” consider sharing the plan with the abutter(s) to make sure they fully understand the work to be performed and the potential impact to their property. This consultation is a courtesy at this stage, and not a regulatory mandate; however, obtaining “buy in” from abutter(s) can potentially avoid neighbor disputes that may lead to costly permitting and/or construction delays.

6) Need a local permit? Share plans with local code enforcement in order to determine what, if any, town ordinances may need to be followed when moving structure, such as shoreland zoning.

7) Need a state permit? If the plan involves alterations below or within 75 feet of highest annual tide (HAT), within or adjacent to another protected natural resource as defined by the Maine Natural Resources Protection Act, or within a development permitted by the Site Location of Development Act, a state permit will likely be required. When possible, plan to meet standards of a permit-by-rule to simplify the state regulatory review process; otherwise an individual permit may be required. Alterations to a development or a lot within a development permitted under the Site Location of Development Act may require the revision or amendment of the development’s permit.

8) Need a federal permit? If the plan involves work below the highest annual tide (HAT) and/or in a freshwater wetland or habitat for endangered or threatened species, a federal permit(s) under the Federal Clean Water Act and Rivers and Harbors Act may be required. Share the plan with all applicable federal authorities in order to determine what permits may be necessary.

9) Hire qualified contractors who are experienced with the best practices associated with construction in or adjacent to natural resources.
 

Move up by elevating structures

Existing structures that are threatened with coastal flooding or erosion often can be elevated to raise the living space above flood level. If your property is located in a flood zone, you may be required by your town’s floodplain management ordinance to have the lowest structural part of your house be elevated above the base flood level. This elevation factor for safety, called freeboard, is one foot for most Maine communities, with a few communities adopting a higher standard. Consult town officials for your local standards.

If you have an older structure that has been flooded and does not meet current standards, or any time you are doing substantial improvements to your structure, consider the cost of elevating the structure using flood vents, a flow-through foundation, or a pile foundation, especially if structural improvements are substantial, meaning the cost of the improvements meets or exceed 50% of the value of the structure. A substantial improvement to a structure requires bringing the structure up to code, including to floodplain management standards. Increasing the elevation may lower insurance costs.

Flow-through foundations are typically block or poured cement foundations with adequate spacing for floodwaters to flow through the foundation without damaging the supports.
Pile foundations are typically used in more active flooding areas along open ocean coastlines, and provide much more open space for floodwaters to travel through.

The concept behind both these foundation types is that water, sediment, and debris can travel through the foundation, thus not applying significant pressure and lateral force to the foundation which can cause structural failure. Both applications can significantly reduce potential flood damage to a structure.

Many of the state requirements regarding elevation of structures, including a review of techniques, are outlined in Chapter 5 of the Maine Floodplain Management Handbook. Your town may have additional requirements that meet or exceed minimum state standards. Contact your local Code Enforcement Officer for more information. You may also want to review the FEMA Coastal Construction Manual and the FEMA Home Builder’s Guide to Coastal Construction Technical Fact Sheets.  The Coastal Construction Manual is available as a CD or in print copy by calling FEMA Publications Distribution Facility at 1-800-480-2520, and should also be available for review at your local town office or public library.

If you consider elevating your structure, think about making other improvements to make your home more storm and flood resilient, such as elevating utilities or tying down heating fuel tanks. Also, consider elevating your structure over and above the elevation required by your floodplain ordinance, in order to take into account expected rates of sea-level rise and higher future floodplain elevations, while lowering your flood insurance premiums.

Follow the steps below to gain the environmental and regulatory information needed for decision making. The steps are listed in general order although some steps may be conducted concurrently.

1) Contact local, state and/or federal regulatory officials. Individuals experienced with coastal regulations may not need to consult officials in all cases; however, if in doubt seek regulatory advice before proceeding with a project.

2) Obtain an environmental assessment from a certified engineer or other qualified professional with expertise in coastal geology and flood hazards. In most cases local, state, and/or federal regulators can help direct you to the best professional discipline to assist with your specific project. Sometimes it is helpful to have the consultant completing the environmental assessment and the construction contractor present at regulatory consultation meetings.

3) Evaluate your risk. Check your insurance coverage to make sure you have adequate liability coverage related to loss due to shoreline erosion or flooding, as well as flood insurance through the National Flood Insurance Program.

4) Develop a mitigation plan if professional and regulatory consultations result in a recommendation that you elevate structures to address coastal erosion or flooding concerns.

5) Be Neighborly. If the plan involves work at or near a property boundary, or if elevating a structure may affect an abutter’s “viewshed,” consider sharing the plan with the abutter(s) to make sure they fully understand the work to be performed and the potential impact to their property. This consultation is a courtesy at this stage, and not a regulatory mandate; however, obtaining “buy in” from abutter(s) can potentially avoid neighbor disputes that may lead to costly permitting and/or construction delays.

6) Need a local permit? Share plans with local code enforcement in order to determine what, if any, town ordinances (such as shoreland zoning) may need to be followed when elevating a structure.

7) Need a state permit? If the plan involves alterations below or within 75 feet of highest annual tide (HAT), within or adjacent to another protected natural resource as defined by the Maine Natural Resources Protection Act, or within a development permitted by the Site Location of Development Act, a state permit will likely be required. When possible, plan to meet standards of a permit-by-rule to simplify the state regulatory review process; otherwise an individual permit may be required. Alterations to a development or a lot within a development permitted under the Site Location of Development Act may require the revision or amendment of the development’s permit.

8) Need a federal permit? If the plan involves work below the highest annual tide (HAT) and/or in a freshwater wetland or habitat for endangered or threatened species, a federal permit(s) under the Federal Clean Water Act and Rivers and Harbors Act may be required. Share the plan with all applicable federal authorities in order to determine what permits may be necessary.

9) Hire qualified contractors who are experienced with the best practices associated with construction in or adjacent to natural resources.

 

Design structures appropriately

Construction techniques that are appropriate to coastal areas involve not only siting of the structure and infrastructure, including septic, utilities, etc., but also design and building techniques that can withstand land, wind, and water forces associated with the dynamic coastal zone.Waterfront Lots for Sale

 

Things to consider:

  • The construction footprint, given applicable setbacks for sensitive areas.
  • The extent of grading needed to achieve a stable building footprint.
  • The level of engineering required to address erosion or flooding.
  • Potential physical forces such as water and wind.

Consult the FEMA Coastal Construction Manual and the FEMA Home Builder’s Guide to Coastal Construction Technical Fact Sheets, which provide detailed descriptions of recommended techniques to mitigate erosion and build smart within the coastal environment. The Construction Manual is available as a CD or in print copy by calling FEMA Publications Distribution Facility at 1-800-480-2520, and should also be available for review at your local town office or public library.

Create or maintain a buffer next to the wetland

Ocean Park HousesKeeping a healthy, diverse, vegetated upland buffer adjacent to a coastal wetland can lessen erosion and protect property. Without a buffer, development disturbs the fringing marsh boundary and may also compromise the wetland's ability to store floodwaters. Fertilizer usage can degrade marsh vegetation and allow colonization by invasive species. If you live on or near a coastal wetland, try to maintain, to the maximum width practicable, a naturally vegetated, woody upland buffer between the “developed” (planted lawn or infrastructure) portion of your property, and adjacent coastal wetlands. Other things you can do include:

  • Enhance the width of existing buffers with native vegetation.
  • Minimize disturbances adjacent to coastal wetlands.
  • Limit planting and maintenance of lawns and subsequent use of nitrogen-rich fertilizers.
  • Remove invasive species within the buffer, especially common reed (Phragmites australis), preferably without the use of pesticides.
  • Limit the amount of unnatural freshwater runoff (or stormwater) directed into coastal wetlands from the adjacent uplands.
  • To avoid impacts to surrounding development, do not block the flow of floodwaters that naturally drain into the wetland.
  • A great general resource for buffer management is from the Save the Bay Narragansett Bay Backyards on the Bay Yard Care Guide for the Coastal Homeowner.

    Case Study: Marsh Buffer

       

       

Follow the steps below to gain the environmental and regulatory information needed for decision making. The steps are listed in general order although some steps may be conducted concurrently.

1) Contact local, state and/or federal regulatory officials. Individuals experienced with coastal regulations may not need to consult officials in all cases; however, if in doubt seek regulatory advice before proceeding with a project.

2) Obtain an environmental assessment from a certified engineer, landscape architect, or other qualified professional. In most cases local, state, and/or federal regulators can help direct you to the best professional discipline to assist with your specific project. Sometimes it is helpful to have the consultant completing the environmental assessment and the construction contractor present at regulatory consultation meetings.

3) Evaluate your risk. Check your insurance coverage to make sure you have adequate liability coverage related to loss due to shoreline erosion or flooding, as well as flood insurance through the National Flood Insurance Program.

4) Develop a mitigation plan if implementation of one or more “best management practices” is recommended. The plan does not need to be prepared by a professional in all cases; however, the quality and clarity of the plan will generally improve the efficiency and timeliness of any subsequent permitting that may be required. Good plans will also benefit the construction contractor and can help prevent costly mistakes.

5) Be Neighborly. If the plan involves work at or near a property boundary, or planting vegetation that may affect an abutter’s “viewshed,” consider sharing the plan with the abutter(s) to make sure they fully understand the work to be performed and the potential impact to their property. This consultation is a courtesy at this stage, and not a regulatory mandate; however, obtaining “buy in” from abutter(s) can potentially avoid neighbor disputes that may lead to costly permitting and/or construction delays.

6) Need a local permit? Share plans with local code enforcement in order to determine what, if any, town ordinances may need to be followed. Local shoreland zoning ordinances may contain requirements for vegetation removal and re-planting.

7) Need a state permit? If the plan involves alterations within 75 feet of highest annual tide (HAT), within or adjacent to another protected natural resource as defined by the Maine Natural Resources Protection Act, or within a development permitted by the Site Location of Development Act, a state permit will likely be required. When possible, plan to meet standards of a permit-by-rule to simplify the state regulatory review process. Typically work within 25 feet of the highest annual tide line is not allowed under permit-by-rule, however there is some exception for disturbances associated with establishing vegetation. An individual permit will be required for any plan that does not qualify for permit-by-rule. Alterations to a development or a lot within a development permitted under the Site Location of Development Act may require the revision or amendment of the development’s permit.

8) Need a federal permit? If the plan involves work below the highest annual tide (HAT) and/or in a freshwater wetland or habitat for endangered or threatened species, a federal permit(s) under the Federal Clean Water Act and Rivers and Harbors Act may be required. Share the plan with all applicable federal authorities in order to determine what permits may be necessary.

9) Hire qualified contractors who are experienced with coastal stabilization projects and the implementation of “best management practices.”

Create or restore wetlands

Planted marshes are generally considered to be one of the most cost-effective and environmentally desirable erosion-control approaches. In contrast to wide “meadow” marshes, fringing marshes are narrow areas of marsh plants lining the shoreline of rivers and bays. Like meadow marshes, fringing marshes protect adjacent uplands by gradually dissipating wave energy, absorbing the force of breaking waves, and stabilizing the soft, underlying soil. Marshes can be created or restored by increasing tidal flow. Additionally, planting marsh grass can be a particularly effective restoration strategy where previous marshes were destroyed by dredging and filling. Planting is also cost-effective, as you may be able to do it yourself.

Marsh planting is most effective in areas that are sheltered from the wind and where waves and boat wakes are not a major problem. A fringing marsh at least 10 feet wide is necessary for erosion control, but 20 feet or more is preferred. If the marsh is not established continuously along the shoreline, erosion can continue on the unprotected areas. In some cases, two or more planting attempts may be required for the marsh to take hold. From a regulatory standpoint, marsh creation or restoration will likely require permitting from state and federal regulatory agencies.

North Carolina's Shoreline Erosion Control Using Marsh Vegetation and Low-Cost Structures provides a good outline for how to plant and create a new coastal wetland. Similarly, the North Carolina Coastal Federation Erosion Control: Non-Structural Alternatives, A Shorefront Property Owner’s Guide provides some good guidance for marsh plantings. The techniques and species discussed in these guides are applicable to Maine’s marsh systems. Tidal bank protection using vegetative plantings is also outlined by the Maine DEP under their Maine Erosion and Sediment Control Best Management Practices.

Commonly used grasses include species native to Maine salt marshes, such as saltmeadow hay (Spartina patens) and smooth cordgrass (Spartina alterniflora). Planting elevations can vary but can be determined by observing the elevations of healthy native marshes nearby. Marsh grasses may be purchased from specialized commercial nurseries (such as Pierson Nurseries in Biddeford), or possibly can be  transplanted from existing marshes with a permit.

Be aware of the threat posed by invasive species. Phragmites australis, also known as common reed, is considered an invasive plant by the State of Maine and should not be planted or allowed to spread.

Increasing tidal flow into marsh areas by removing or replacing inadequately functioning road culverts can help facilitate the natural proliferation of marsh plants. Adequate tidal flushing is required for marsh growth, and also helps eliminate invasive species that are not salt-tolerant. Increasing tidal flow also helps dissipate floodwaters by allowing water to drain naturally to the ocean, while restricting the flow will often increase flooding. Note that permits are likely required from Maine DEP and the US Army Corps of Engineers for work associated with road culverts.

The above marsh restoration information was adapted from Managing Erosion on Estuarine Shorelines, which was prepared for estuarine shorelines in North Carolina. However, much of the information and techniques outlined transfer to Maine’s marshes. Additional online resources regarding techniques that provide good guidance for marsh restoration and creation include Maine Salt Marshes: Their Function, Values, and Restoration and Salt Marshes in the Gulf of Maine, Human Impacts, Habitat Restoration and Long-Term Change Analysis.

Follow the steps below to gain the environmental and regulatory information needed for decision making. The steps are listed in general order although some steps may be conducted concurrently.

1) Contact local, state and/or federal regulatory officials. Individuals experienced with coastal regulations may not need to consult officials in all cases; however, if in doubt seek regulatory advice before proceeding with a project.

2) Obtain an environmental assessment from a certified engineer, landscape architect, or other qualified professional. In most cases local, state, and/or federal regulators can help direct you to the best professional discipline to assist with your specific project. Sometimes it is helpful to have the consultant completing the environmental assessment and the construction contractor present at regulatory consultation meetings.

3) Evaluate your risk. Check your insurance coverage to make sure you have adequate liability coverage related to loss due to shoreline erosion or flooding, as well as flood insurance through the National Flood Insurance Program.

4) Develop a mitigation plan if implementation of one or more “best management practices” is recommended. The plan does not need to be prepared by a professional in all cases; however, the quality and clarity of the plan will generally improve the efficiency and timeliness of any subsequent permitting that may be required. Good plans will also benefit the construction contractor and can help prevent costly mistakes.

5) Be Neighborly. If the plan involves work at or near a property boundary, or activity that may affect an abutter’s “viewshed,” consider sharing the plan with the abutter(s) to make sure they fully understand the work to be performed and the potential impact to their property. This consultation is a courtesy at this stage, and not a regulatory mandate; however, obtaining “buy in” from abutter(s) can potentially avoid neighbor disputes that may lead to costly permitting and/or construction delays.

6) Need a local permit? Share plans with local code enforcement in order to determine what, if any, town ordinances may need to be followed. Local shoreland zoning ordinances generally contain requirements for vegetation removal and re-planting.

7) Need a state permit? If the plan involves alterations within 75 feet of highest annual tide (HAT), within or adjacent to another protected natural resource as defined by the Maine Natural Resources Protection Act, or within a development permitted by the Site Location of Development Act, a state permit will likely be required. When possible, plan to meet standards of a permit-by-rule to simplify the state regulatory review process. Typically work within 25 feet of the highest annual tide line is not allowed under permit-by-rule, however there is some exception for disturbances associated with establishing vegetation. An individual permit will be required for any plan that does not qualify for permit-by-rule. Alterations to a development or a lot within a development permitted under the Site Location of Development Act may require the revision or amendment of the development’s permit.

8) Need a federal permit? If the plan involves work below the highest annual tide (HAT) and/or in a freshwater wetland or habitat for endangered or threatened species, a federal permit(s) under the Federal Clean Water Act and Rivers and Harbors Act may be required. Share the plan with all applicable federal authorities in order to determine what permits may be necessary.

9) Hire qualified contractors who are experienced with coastal stabilization projects and the implementation of “best management practices.”

Add rip-rap to wetlands

Rip-rap (angular stone in various sizes usually larger than two feet in diameter) is generally not recommended because it limits the ability of coastal wetlands to move (or migrate) inland, and also limits the transfer of sediment from uplands that are critical to the long term sustainability of coastal wetlands. It may be possible to use rip-rap to protect property in situations where no other viable alternative is readily available. An individual permit will be required from Maine DEP in order to pursue rip-rap placement adjacent to or within a coastal wetland.

Rip-rap best management practices for placement and construction techniques are available from Maine DEP. Other good resources include the North Carolina Coastal Federation Erosion Control: Non-Structural Alternatives, A Shorefront Property Owner’s Guide, Shoreline Erosion Control Using Marsh Vegetation and Low-Cost Structures, and Maine DEP’s guide for the use of gabions.

Follow the steps below to gain the environmental and regulatory information needed for decision making. The steps are listed in general order although some steps may be conducted concurrently.

1) Contact local, state and/or federal regulatory officials. Individuals experienced with coastal regulations may not need to consult officials in all cases; however, if in doubt seek regulatory advice before proceeding with a project.

2) Obtain an environmental assessment from a certified engineer, coastal geologist, or other qualified professional. In most cases local, state, and/or federal regulators can help direct you to the best professional discipline to assist with your specific project. Sometimes it is helpful to have the consultant completing the environmental assessment and the construction contractor present at regulatory consultation meetings.

3) Evaluate your risk. Check your insurance coverage to make sure you have adequate liability coverage related to loss due to shoreline erosion or flooding, as well as flood insurance through the National Flood Insurance Program.

4) Develop a mitigation plan if implementation of one or more “best management practices” is recommended. The plan does not need to be prepared by a professional in all cases; however, the quality and clarity of the plan will generally improve the efficiency and timeliness of any subsequent permitting that may be required. Good plans will also benefit the construction contractor and can help prevent costly mistakes.

5) Be Neighborly. If the plan involves work at or near a property boundary, consider sharing the plan with the abutter(s) to make sure they fully understand the work to be performed and the potential impact to their property. This consultation is a courtesy at this stage, and not a regulatory mandate; however, obtaining “buy in” from abutter(s) can potentially avoid neighbor disputes that may lead to costly permitting and/or construction delays.

6) Need a local permit? Share plans with local code enforcement in order to determine what, if any, town ordinances (such as shoreland zoning) may need to be followed.

7) Need a state permit? If the plan involves alterations within 75 feet of highest annual tide (HAT), within or adjacent to another protected natural resource as defined by the Maine Natural Resources Protection Act, or within a development permitted by the Site Location of Development Act, a state permit will likely be required. An individual permit will be needed, since coastal rip-rap projects do qualify for permit-by-rule, and the permit application will have to provide a compelling argument that existing structures on the property are in danger. Alterations to a development or a lot within a development permitted under the Site Location of Development Act may require the revision or amendment of the development’s permit.

8) Need a federal permit? If the plan involves work below the highest annual tide (HAT) and/or in a freshwater wetland or habitat for endangered or threatened species, a federal permit(s) under the Federal Clean Water Act and Rivers and Harbors Act may be required. Share the plan with all applicable federal authorities in order to determine what permits may be necessary.

9) Hire qualified contractors who are experienced with coastal stabilization projects and the implementation of “best management practices.”

Build a seawall

Seawalls are not generally recommended because they limit the migration and the transfer of sediment that is critical to the long-term sustainability of coastal marshes. Seawalls may accelerate erosion at the ends of the structure.

But in situations where no other viable alternative is readily available, it may be possible to construct a seawall in or adjacent to a coastal marsh to protect property in proximity to an eroding bank. An individual permit will be required from Maine DEP in order to pursue construction of a seawall that impacts a coastal marsh, but generally Maine DEP will not approve the use of a seawall in most coastal wetland areas.

Additionally, new seawalls are not allowed in coastal sand dune systems.

Both of the photos below are from the same cove. The photo on left shows property where a wall was constructed many years ago. The photo on the right shows property without walls where an extensive wetland persists and buffers the residence from the waves.

 image of coastal property with seawall and no wetland bufferimage of coastal property without walls and natural wetland

 

 

 

 

 

 

Rebuilding after severe storm damage

There is no standard process property owners can follow in the case of a catastrophic event that damages the shoreline of a coastal wetland. Property owners are encouraged to contact state and local officials immediately. Permits for stabilization and/or restoration of the shoreline will be required, so seek guidance before beginning any work.