Habitat restoration on eroded beaches, dunes and coastal banks, may contribute significantly to stabilization but cannot reverse the overall “net loss” from our coastal erosion process on the Outer Cape. Sustainable practices and responses view these habitats as “systems”, linking geomass, biomass and the energy that drives through them. This systems approach can focus restoration effort, minimize loss and prevent additional, unnecessary losses from anthropogenic impacts. In some, site specific cases (shown below), it is possible to restore geomass and re-connect eroded profiles.
Outer Cape coastal habitat is made up of sand and grass, ocean, wind and people. Safe Harbor’s restoration strategies use the systems approach, incorporating natural energy forces in each habitat. In some cases, the energy we utilize to restore an area, such as wind, is the same energy that has eroded the area.
We use low tech, low profile, restoration systems. In a way, our approach is similar to baking bread: you need to know the the relationships between ingredients, put them together, expose the ingredients to energy and get out of the way. Except our “oven” happens to be the North Atlantic coast of Cape Cod.
Responses to coastal erosion usually include the first four alternatives listed below:
1. “no action” do nothing
2. “hard” armored structure (bulkhead, groin, jetty);
3. “semi-soft” (semi-structural) drift fencing and/or coir/fiber rolls;
4. “soft” sand renourishment;
5. “sustainable” habitat restoration.
While semi soft and soft solutions may incorporate some elements of restoration, we will be discussing alternative # 5: sustainable coastal habitat restoration. Remember the caveat that the coastal erosion process is site specific and based on net loss. Restoration strategies may not be interchangeable or appropriate for every case. We believe that habitat systems, if restored to sustinability, minimize net loss by allowing the system to respond to the coastal process. We will use Case Study #2, on Cape Cod Bay and Case Study #3, on the Atlantic Ocean, as models for our techniques.
Sustainable habitat restoration is a unique alternative because it doesn’t just respond to the problem, it addresses the cause of the problem as part of the solution. In these two case studies, we will share our protocols for restoration and a little of our assessment process. Any coastal erosion site represents a unique set of factors and should be assessed carefully. In case study 2 and 3, anthropogenic impacts removed vegetation, exposing the land form to mass reducing erosion. Our restoration solutions incorporated the same wind that eroded these areas, to restore them. Habitat Restoration may not be an acceptable alternative in every case.
Residents crossing a dune along a public landing damaged beach grass. The missing grass allowed winds to scour a 14′ deep hole on the beach and pile the excess sand 14′ high, on the top of the path. Residents now needed to negotiate a 28; drop and climb to get to the beach. As a result they began short cutting across an abuttor’s property, which also began eroding.
While this project may seem like a “soft” project, the renourished sand was critical for storm damage prevention. After that sand was in place, we plugged in our fairly low tech restoration system. 24″ sand fencing was installed in 4′wide, parallel rows, beginning at the toe of where we wanted to restore the dune. As sand fills in, we will adjust new fencing to link to the adjacent dune, on each side. Grass plantings, on this site, are critical to creating sustainable habitat.
Photo below was taken one year later, showing new sand collected from storm winds, which will continue to restore this dune. Planted beach grass will grow right up through the collected sand.
Missing vegetation may have been removed in the past for a view. Currently, sand was blowing up to the top of the windows of an adjacent home. We wanted to create a few vegetated dunes on top of the bluff to slow down the wind and collect sand naturally, with a sustainable system.
Collected sand filled up to beach grass seed head this particular winter. New fencing was added to continue shaping the land form. Dune or beach profiles can be created by placement of fencing, which performs the same role as beach grass until the grass is dense enough to make the system sustainable by itself. The buried beach grass will grow right up through the new sand.
For questions, contact Gordon Peabody, gordonsafeharbor@yahoo.com