Eco-Restoration Journey Week 24: ‘Water is a force to be reckoned with’

Before Harwich Conservation Trust’s (HCT) Hinckleys Pond — Herring River Headwaters Eco-Restoration Project got started, erosion caused by rainfall runoff was gnawing away at a steep bank near Hinckleys Pond.

For many years, storms were sending sediment downhill into the pond. The relentless erosion meant that plants never had a chance to naturally anchor the slope.

An important part of the project was figuring out how to better convey the water down the hillside, minimizing the possibility of erosion during heavy rain events.

A rock-lined swale was built to convey water down a steep slope and limit erosion at Harwich Conservation Trust’s Hinckleys Pond — Herring River River Eco-Restoration Project. 

Redirecting water takes careful thought and engineering. “Water is a force to be reckoned with,” said Mike Lundsted, Project Manager for SumCo Eco-Contracting. “Controlling it is always one of the toughest things on all of our projects.” 

Most of the Hinckleys Pond — Herring River Preserve is located on the west side of the Cape Cod Rail Trail, with an overlook area on the east side of the bike trail, next to Hinckleys Pond.

A gently sloped, stabilized stone dust path will lead visitors from the main part of the Preserve to a painted crosswalk that will span the rail trail. Another gently sloped path on the east side of the bike trail will descend the bank to the overlook area on the pond.

The bike trail crossing area is where rainfall would pool during storms, then spill down the bank toward the pond. “The rail trail slopes down in both directions to that spot, so the water collects there,” said Lundsted. “That’s why we saw the erosion before the project started.”

A plan to battle erosion

To limit erosion in the area, SumCo built a rock-lined swale that leads down the bank. “The idea is to catch and convey the water down the slope and keep it off of our stabilized stone dust path,” said Lundsted.

The anti-erosion effort didn’t stop there. A native seed mix, supplemented with annual rye, was put down on the steep bank. This mix was covered with a biodegradable fabric. “”The fabric is a temporary stabilization measure,” said Lundsted. “It gives the seed a chance to take.”

A native seed mix, supplemented with annual rye, was put down on the steep bank, then covered with a biodegradable fabric that stabilizes the area while the seeds germinate. The annual rye is already popping up. 

The annual rye, a quick-growing cover crop, is already poking up through the fabric. The combination of fabric and annual rye creates a stable environment for the native seeds to germinate and thrive. By absorbing water, plants can slow and diffuse water runoff, and their roots hold soil in place.

As a temporary measure while the seeds are germinating, net tubes filled with straw (called straw wattles) will be placed at the top of the bank to limit the amount of water that can descend through the planted area.

While significant rain events have been rare on Cape Cod over the summer, a recent downpour provided a good test of the erosion-control measures put in place.

“It seems to be working well,” said Lundsted. “During the storm, there was a little river running down the rock-lined swale. I think with the infrastructure we’ve put in, it will certainly be better than what was here before.”

Project refresher

The Hinckleys Pond – Herring River Headwaters Eco-Restoration Project includes the restoration of two retired cranberry bogs that bookend 174-acre Hinckleys Pond in Harwich, located at the headwaters of the Herring River estuary. Hinckleys Pond is also connected by streams to river herring spawning habitat in Long Pond and Seymour Pond.

Harwich Conservation Trust’s Hinckleys Pond — Herring River Headwaters Eco-Restoration Project includes the rewilding of two retired cranberry bogs that bracket Hinckleys Pond, indicated with red circles. The blue arrows pointing into the three ponds show upstream migration of river herring each spring.

By the late 1990s, much larger off-Cape bogs were producing an extra supply of cranberries that caused the price to fall. This shift in the industry makes it more difficult for local growers to continue farming. Some are looking to exit the industry.

Farmers have a choice. They can either sell their properties for conversion of the upland to subdivisions which can cause water quality changes and end up closing off public access to the land. Or they can seek a conservation future by selling to local land trusts and towns. In 2021 at Hinckleys Pond, the Jenkins family finished their farming chapter and chose to sell their 31 acres to HCT for the next chapters of conservation and eco-restoration.

The Brown family, who owns a retired bog on the other side of the pond, is also partnering with HCT on the project. The collaborative eco-effort will increase biodiversity and restore freshwater wetland habitat as well as enhance opportunities for everyone to enjoy the trails, views and wildlife watching.

The eco-restoration project is funded by HCT donors, the Brown family, U.S. Environmental Protection Agency (EPA) Southeast New England Program (SNEP) Watershed grant, EPA National Estuary Program Coastal Watershed grant under cooperative agreement with Restore America’s Estuaries, Massachusetts Department of Conservation & Recreation MassTrails grant, foundation funds through the Association to Preserve Cape Cod, and a Transformational Habitat Restoration & Coastal Resilience grant through the National Oceanic & Atmospheric Administration.

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