Two Dams Removed in the Hudson River Watershed

The Hudson River provides habitat for approximately 85% of New York State’s fish and wildlife species, 200 of which rely on the Hudson River for spawning, nursery, and forage habitat. According to Riverkeeper, a nonprofit focused on protecting and restoring the Hudson River, there are approximately 1,600 dams, mostly obsolete, fragmenting the rivers and streams of the Hudson Valley and blocking fish from reaching critical habitat.

The recent removal of two defunct dams – The Strooks Felt Dam and Furnace Brook Barrier #1 – marks an important milestone in the Riverkeeper’s journey to “Undam the Hudson River” and restore fish passage between the Hudson and the Atlantic Ocean. 

The removal of these dams, located on tributaries of the Hudson River, are especially important to depleted populations of migratory fish like river herring and American eel, who are a vital part of the coastal ecosystem and spawn in freshwater tributaries. 

Funding for both projects was provided by the Environmental Protection Fund and administered by the Department of Environmental Conservation (DEC). Riverkeeper led the effort to remove the obsolete dams, with Princeton Hydro providing dam and stream assessment, surveying, engineering design, and permitting assistance. 

Strooks Felt Dam

For the first time in 300 years, fish in the Quassaick Creek will be able to move upstream thanks to the dismantling of the 106-year-old, 4-foot-high Strooks Felt Dam in Newburgh, New York, located 60 miles north of New York City in the critical estuary of the Hudson River. 

The dam site was dominated by gravel, cobble, boulder, and even bedrock steps, indicating a high-energy stream with a high sediment transport potential. This dam removal, like many others, released this coarse sediment and allowed the creek to carry it to downstream reaches. This coarse sediment forms habitat features like riffes, bars, and pools that are crucial components of healthy streams and rivers. Releasing the impounded bedload by removing these dams is key to increasing the resilience of freshwater streams like Quassaick Creek. 

Downstream of spillway facing west

The dam removal, which was completed in October 2020, involved excavating the concrete spillway before reshaping and re-grading bedload sediment behind the dam.

Historically, the Strooks Felt Dam was part of a series of older dams that sat in slightly different positions in the same area and supplied former mill operations. Other nonobstructive structures associated with the former mill were left as part of an enduring history, allowing anyone who visits the site or combs through the records to visualize what was there before. The obsolete dam, however, will no longer block water, sediment, or critical fish passage

Project collaborators included: Riverkeeper, Orange County and the City of Newburgh, the Town of New Windsor, DEC Hudson River Estuary Program, Quassaick Creek Watershed Alliance, Steelways Inc, RiverLogic Solutions, and Princeton Hydro. 

Two additional dams farther upstream from the former Strooks Felt Dam site are in the early planning stages for removal.


Furnace Brook Barrier #1

The 5-foot-high, 75-foot-long Furnace Brook Barrier #1 was dismantled in Westchester County, New York in mid-November 2020. The removal of this dam brings migratory fish one-step closer to reconnecting with their ancestral habitat.

Furnace Brook Dam removal. Photo courtesy of RiverKeeper.

The positive results were immediate. Riverkeeper stated in a recently published article, “As soon as a path was cleared, we spotted two fish – white suckers, a freshwater species – darting up to the previously unreachable part of the brook. We can’t wait to come back in the spring and see whether herring, returning from the ocean, are migrating upstream…”

The dam clearing process at Furnace Brook involved the removal of the dam and an existing collapsed former concrete bridge span downstream of the dam. Stone masonry boulders from the former spillway were then redistributed and partially embedded in the restored channel to enhance aquatic habitat and increase bank stabilization

Project collaborators included Rivekeeper, NYSDEC’s Hudson River Estuary Program, Westchester County Parks Department, Westchester County, the dam owner, the town of Cortlandt, the Friends of the McAndrews Estate, and Princeton Hydro. 

Upstream of this project, Princeton Hydro is developing an initial engineering design and sediment management plan for the removal of another, larger dam.

The collapsed concrete bridge deck was also removed as part of this project.


Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of dozens of small and large dams throughout the Northeast. To learn more about our dam engineering and removal services, visit:

UPDATE: Hudson River Habitat Restoration Study Completed & Chief’s Report Signed

Photo from USACE

As part of the multi-faceted effort to restore the vital Hudson River ecosystem, the USACE New York District launched the Hudson River Habitat RestorationPrinceton Hydro led the Hudson River Habitat Restoration Integrated Feasibility Study and Environmental Assessment for USACE. For this project, we established and evaluated baseline conditions through data collection and analysis; developed restoration objectives and opportunities; prepared an Environmental Assessment; and designed conceptual restoration plans for eight sites.

This week, Lt. Gen. Scott A. Spellmon, USACE Commanding General and 55th U.S. Army Chief of Engineers, signed the Hudson River Habitat Restoration Ecosystem Restoration Chief’s Report, which represents the completion of the study and makes it eligible for congressional authorization.

As stated in the USACE-issued news release, “The Chief’s Report recommends three individual ecosystem restoration projects including Henry Hudson Park, Schodack Island Park, and Moodna Creek within the 125-mile study area from the Federal Lock and Dam at Troy, NY to the Governor Mario M. Cuomo Bridge. These projects would restore a total of approximately 22.8 acres of tidal wetlands, 8.5 acres of side-channel and wetland complex, and 1,760 linear feet of living shoreline with 0.6 acres of tidal wetlands. The plan would also reconnect 7.8 miles of tributary habitat to the Hudson River through the removal of 3 barriers along Moodna Creek.”

“The signing of this Chief’s Report is a significant milestone for the HRHR Project,” said Col. Matthew Luzzatto, USACE New York District Commander. “This has truly been a team effort and I want to thank our non-federal sponsors, New York State Department of Environmental Conservation and New York State Department of State, and all of our engineers, scientists, and partners at the local, state and federal level for their unwavering support.”

Read the full press release here. And, for more background information on the Feasibility Study and proposed restoration work, check out our original blog post:

Feasibility Study Identifies Key Opportunities for Hudson River Habitat Restoration

Feasibility Study Identifies Key Opportunities for Hudson River Habitat Restoration

Hudson River Bear Mountain Bridge (Photo from Wikipedia)

The Hudson River originates at the Lake Tear of the Clouds in the Adirondack Mountains at an elevation of 4,322 feet above sea level. The river then flows southward 315 miles to New York City and empties into the New York Harbor leading to the Atlantic Ocean. The Hudson River Valley lies almost entirely within the state of New York, except for its last 22 miles, where it serves as the boundary between New York and New Jersey.

Hudson River Basin (Image by USACE)Approximately 153 miles of the Hudson River, between the Troy Dam to the Atlantic Ocean, is an estuary. An estuary is defined by the USEPA as “a partially enclosed, coastal water body where freshwater from rivers and streams mixes with salt water from the ocean. Estuaries, and their surrounding lands, are places of transition from land to sea. Although influenced by the tides, they are protected from the full force of ocean waves, winds and storms by landforms such as barrier islands or peninsulas.”

The Hudson River’s estuary encompasses regionally significant habitat for anadromous fish and globally rare tidal freshwater wetland communities and plants, and also supports significant wildlife concentrations. As a whole, the Hudson River provides a unique ecosystem with highly diverse habitats for approximately 85% of New York State’s fish and wildlife species, including over 200 fish species that rely on the Hudson River for spawning, nursery, and forage habitat.

The Hudson is an integral part of New York’s identity and plays a vital role in the lives of the people throughout the area. Long valued as a transportation corridor for the region’s agricultural and industrial goods, and heavily used by the recreation and tourism industries, the Hudson plays a major role in the local economy. It also provides drinking water for more than 100,000 people.

At the end of the American Revolution, the population in the Hudson River Valley began to grow. The introduction of railroad travel in 1851 further accelerated development in the area. Industrial buildings were erected along the river, such as brick and cement manufacturing, which was followed by residential building. Along with the aforementioned development, came the construction of approximately 1,600 dams and thousands of culverts throughout the Hudson River.

According to the U.S. Army Corps of Engineers (USACE), these human activities have significantly degraded the integrity of the Hudson River ecosystem and cumulatively changed the morphology and hydrology of the river. Over time, these changes have resulted in large-scale losses of critical shallow water and intertidal wetland habitats, and fragmented and disconnected habitats for migratory and other species. Most of this loss and impact has occurred in the upper third portion of the estuary.

As part of the effort to restore the vital river ecosystem, the USACE New York District launched a Hudson River Habitat Restoration Feasibility Study, which helps to establish and evaluate baseline conditions, develop restoration goals and objectives, and identify key restoration opportunities. Princeton Hydro participated in data collection and analysis, conceptual restoration designs, and preparation of the USACE Environmental Assessment for the Hudson River Habitat Restoration Ecosystem Restoration Draft Integrated Feasibility Study and Environmental Assessment.

Basic map depicting project sites (Created by Princeton Hydro)The study area includes the Hudson River Valley from the Governor Mario M. Cuomo Bridge downstream to the Troy Lock and Dam upstream. The primary restoration objectives include restoring a mosaic of interconnected, large river habitats and restoring lost connectivity between the Hudson River and adjacent ecosystems.

A total of six sites were evaluated using topographic surveys, installation and monitoring of tide gauges, evaluation of dam and fish barrier infrastructure, and field data collection and analysis to support Evaluation of Planned Wetlands (EPW) and Habitat Suitability Indices (HSI) functional assessment models. Literature reviews were also completed for geotechnical, hazardous toxicity radioactive waste, and aquatic organism passage measures.

Multiple alternatives for each of the six sites were created in addition to the preparation of conceptual designs, quantity take-offs, and cost estimates for construction, monitoring and adaptive management, and long-term operation and maintenance activities.

Princeton Hydro also prepared an environmental assessment in accordance with NEPA standards, addressing all six sites along the Hudson River and its tributaries. This assessment served to characterize existing conditions, environmental impacts of the preferred Proposed Action and No Action Alternatives, and regional cumulative environmental impacts. Our final report was highlighted by USACE at the 2019 Planning Community of Practice (PCoP) national workshop at the Kansas City District as an example of a successfully implemented Ecosystem Restoration Planning Center of Expertise (ECO-PCX) project.

USACE’s specific interest in Hudson River restoration stems from the aforementioned dramatic losses of regional ecosystems, the national significance of those ecosystems, and the apparent and significant opportunity for measurable improvement to the degraded ecological resources in the river basin.

The feasibility study is among the first of several critical steps in restoring the Hudson River’s ecosystem function and dynamic processes, and reestablishing the attributes of a natural, functioning, and self-regulated river system. Stay tuned for more updates on the Hudson River restoration efforts.

*FREE* Download: Using Flood Models to Mitigate Flood Risk

Back in September, NEIWPCC offered a free research webinar on modeling and flood mitigation recommendations for a forested and urban Hudson River tributary watershed. The webinar looked at the Moodna Creek Watershed and Flood Mitigation Assessment and described how flood models were used to inform recommendations for reducing and mitigating existing and anticipated flood risk. This free webinar was hosted by our Environmental Scientist & GIS Manager, Christiana Pollack, GISP, CFM, and Jessica Jahre, CFM, AICP, a Planner with the New Jersey Department of Environmental Protection.

Pollack and Jahre, authors of the assessment, described how they used flood models to inform recommendations for reducing and mitigating existing/anticipated flood risk in the Moodna Creek Watershed. The flood mitigation assessment was conducted by Princeton Hydro and GreenVest, and funded by NEIWPCC through the New York Department of Environmental Conservation’s Hudson River Estuary Program.

If you missed the webinar, but are still interested in flood mitigation and this study, you can download a PDF of the Powerpoint below. With informative graphics and intriguing photos, this presentation will introduce you to flood mitigation strategies and techniques for many different needs.Princeton Hydro specializes in flood planning, policy, analysis, design and risk mitigation services.  To learn more our floodplain management services, visit: