Wetland restoration with dredged material proving successful in Buffalo’s back yard

Photo By Avery Schneider | Ecologist Andrew Hannes of the U.S. Army Corps of Engineers Buffalo District gives members of Leadership Buffalo's Rising Leaders group a tour of a Beneficial Use of Dredged Material Ecosystem Restoration Project at Unity Island in Buffalo, New York, September 22. The Buffalo District completed construction of the project in fall 2020, creating a total 10 acres of coastal wetland habitat to benefit the health of the Great Lakes. (U.S. Army Photo by Avery Schneider)

Posted on October 20, 2021

What was once nearly a landfill is now a thriving wetland ecosystem in the City of Buffalo’s back yard.

At Unity Island on the West Side of the city, the U.S. Army Corps of Engineers, Buffalo District spent two years building the basis for a wetland using material dredged from the nearby Buffalo River. Nearly a year after construction was completed, the island’s North Pond is showing tremendous results.

— What happened at Unity Island? —

“This region has a long history of wetland loss,” said Andrew Hannes, ecologist with the USACE Buffalo District.

Slow and shallow water habitats critical to healthy aquatic ecosystems in the area have been depleted by erosion and manmade impacts over the course of the 20th century.

In the 1900s, Unity Island was used as Buffalo’s landfill, and its north pond was originally constructed to receive more waste. When the island was remediated in 2000 and re-opened as a park by the city and the New York State Department of Environmental Conservation, the north pond was left sitting as a pool of deep water, disconnected from the Niagara River just outside its west embankment.

Upstream from Unity Island is the Buffalo River, which was declared biologically dead in 1969 after decades of industrial and municipal pollution. In 2011, as part of a community-led effort, USACE and the U.S. Environmental Protection Agency began navigational dredging of the river to make way for environmental dredging by the EPA, New York State’s Department of Environmental Conservation, Honeywell, and Buffalo Niagara Riverkeeper. More than 1 million cubic yards of contaminated sediment were removed.

In the years that followed, sediment removed from the river’s federal navigation channel as part of ongoing navigational dredging by USACE was certified as clean by state and federal standards and acceptable for beneficial use.

Then came 2018.

“We kind of saw [Unity Island’s North Pond] and said, ‘Wow. Here is this cool opportunity – deep water over here totally disconnected from the rest of the river. Let’s bring the dredged material down the Black Rock Canal, tie up [next to the island], place it in here, shallow the depths and create a wetland. And that’s what we did,” Hannes said.

The project was funded through USACE’s Continuing Authorities Program 204 and a Habitat Enhancement and Restoration Fund grant awarded to the City of Buffalo from the New York Power Authority.

Construction started in May 2018 with placement of 56,000 cubic yards of dredged material in less than two months. Crews shallowed the pond’s depths to wetland vegetation-friendly elevations, opened the stone dike between the Niagara River and the pond, reconnecting 10 acres of backwater habitat to the main stem Niagara River. They reused stone from the dike to create an underwater reef and added vegetation to the site over the course of two years.

— The results —

A September 2021 monitoring report by USACE illustrates how the pond is now providing a high-quality habitat for native aquatic animal and plant life.

The site’s score on the Lake Erie/Lacustuary Qualitative Habitat Evaluation Index (LQHEI) rose by 128.8%. The index measures substrate type and quality, cover types, shoreline morphology, riparian zone and bank erosion and aquatic vegetation quality. Measurements were taken prior to the project beginning and again in 2021, and a final measurement will be taken in 2023.

In September 2019 and September 2020, survey teams monitoring the survival and establishment of the wetland’s plant community in the North Pond found native emergent and submerged aquatic vegetation had flourished on the dredged material and, as of 2020, exceeded the project’s performance criteria of more than 50% coverage of native species with a score of 54.6%. That equates to more than 35,000 square feet of diverse new plant life that can self-sustain year after year.

“The plants just took off out of this sediment,” Hannes said.

Fish monitoring techniques including gillnetting, minnow traps, and electrofishing over the course of 2017, 2018 and 2019 showed a two-fold increase in species richness and abundance, thanks to the project. It also found that the North Pond has become a nursery habitat for young-of-the-year size classes of native species. Altogether, a total of 24 different species of fish were sampled, including muskellunge and northern pike – two indicators of high habitat quality.

— What people are saying —

Just a couple of weeks after the monitoring report was issued, Hannes was asked to present the project to young professionals from Leadership Buffalo as part of their Environment and Ecology day.

Standing on the banks of the pond, he told the story of Unity Island’s history and the efforts to make it a place not only beneficial to plants and wildlife, but to the many residents and visitors in the City of Buffalo who enjoy the park’s grassy fields, secluded trails, and quiet fishing spots.

“What’s striking is looking at the wetland over here and the fact that it was done just three years ago. And seeing how much its changed since then is remarkable,” said Andrew Emhoff, a member of Leadership Buffalo’s current class of Rising Leaders. “I think it just speaks to how resilient nature can be when you give it the opportunity.”

For many in the group, what’s happening at Unity Island is still one of Buffalo’s better kept secrets. And for some, the tour marked their first visit to the island.

“I always see it when I’m on the expressway, but I have never been here,” said Rising Leader Kent Olden. “So, to come here today and see everything that’s going on as far as the preservation of the water and maintenance of the wetlands – and its right here in the heart of Buffalo – it’s very encouraging and uplifting.”

— What’s next for beneficial use of dredged material? —

For all the project’s success, it’s important to note that the need for wetland restoration is not just a local issue.

“It’s not unique to Buffalo. It not unique to Western New York by any means,” Hannes said.

What is unique – or at least was when work on Unity Island began – is the project itself. The effort was the first of its kind in the Great Lakes, and its success has led to the planning and creation of other similar, larger projects.

While the Unity Island beneficial use project started relatively small, with just 56,000 cubic yards of dredged material, a new wetland site at Buffalo’s Outer Harbor will use 285,000 cubic yards, and another in Ashtabula, Ohio will use up to 400,000 cubic yards.

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The Buffalo District delivers world class engineering solutions to the Great Lakes Region, the Army and the Nation in order to ensure national security, environmental sustainability, water resource management, and emergency assistance during peace and war.

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