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This is the fifth in a series of articles about how landowners can harness “The Power of Plants” to maintain shorefront property while following the rules established to protect these environmentally sensitive areas. The Harpswell Conservation Commission is organizing the series, with articles by local experts.
In this article, commission member Wendy Batson interviews Lance Linkel, founder of Linkel Environmental, which specializes in comprehensive solutions to protect coastal homes against erosion while preserving the environment. His answers are edited for clarity and length.
People call us in alarm because they see their land disappearing. If close to the ocean, that loss can come from erosion caused by the ocean through wave action or from groundwater erosion.
A lot of Maine slopes are clay. When clay is dry, it’s hard like brick. When wet, it’s soft, malleable and slippery. If you don’t have anything growing on it, there’s nothing to soak up the water in the clay.
Harpswell has many kinds of rock — from granite to that brown stuff that crumbles in your fingers. When a big wall of that unstable rock freezes, the moisture in the rock expands, breaks it into pieces and the whole wall shears off. We put rock in front of that to hold it in place and stop the collapse.
Changing weather patterns are making erosion worse. We’ve been getting more of these astronomical high tides alongside changing storm and wind directions. Freezing has become less predictable. People are concerned about the growing effects of sea-level rise.
When we get a call from a worried homeowner, first thing we do is come down and assess the problem to find a good fit. When we look at a project, we’ll consider the whole setup — the house, the gutters, the driveways, parking areas and the septic. Groundwater coming off your roof, the lawn and driveway concentrates and moves faster than normal. When surface water gains speed and momentum, it is quite destructive. If the area is wooded, it’ll soak up the water before it races downhill.
You need to make sure there’s a place for the surface water to go. We construct swales to direct the water away from problem areas. We can channel it into a stone-lined ditch so we can get it down the slope. Sometimes we’ll dig a trench and use piping to catch the groundwater and move it down to the shore — this helps dry out the clay.
We’ll consider a range of solutions, from nature-based approaches that use logs and plants, to hardscape that depends on rock, or a combination of both. If you live on the leeward side of an island or in an estuary, nature-based solutions are a sound approach. But if you’re out on Bailey Island on a clay bank, core logs and plants alone won’t work, but a combination of rock and natural materials might.
If a slope is really steep, we’ll cut it back to take weight off of it. You’ll lose a little bit of land, but with weight off the edge, there’s less chance of a much larger failure, which happens when the slope gets too steep and there’s undercutting from wave and storm action. If we can stop the erosion by placing rock at the toe of the slope, the whole bank will hold, and the rock will absorb the energy from the waves.
We can put riprap down low and plants above it, or we’ll do riprap and cable oak logs to the bank shoulder with a little fabric behind that and install plants behind everything. We use a hybrid system where we place rock filled in with dirt and plants.
I don’t do small. When people think riprap, they imagine 6- to 12-inch rock. We use locally sourced 4- to 5-foot rock, which really holds, looks more natural and keeps the wave action from going into the clay. I’m a rock guy who likes permanent structures, so I advocate for rock, at least at the toe and at the top. I don’t want to have to come back. Nature-based solutions usually have a lifespan. When hit by a storm, a lot of times, you have to go and redo it. A lot of people now want to do the nature-based stuff, but they also want a one-and-done where they don’t have to worry about losing any more property.
The Maine Department of Environmental Protection’s OUR SHORE program offers a helpful checklist and guidance to homeowners for assessing erosion risk. For more information, go to maine.gov/dep and search for OUR SHORE.
