We’re committed to improving our ecosystems, quality of life, and communities for the better.
Our passion and commitment to the integration of innovative science and engineering drive us to exceed on behalf of every client.
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We're pleased to announce the release of the "New Jersey Nature-Based Solutions: Planning, Implementation, and Monitoring Reference Guide," a free resource that provides a comprehensive roadmap to incorporating nature-based solutions (NBS) into infrastructure, construction, restoration, and resilience projects across the state.
Created by the Rutgers University New Jersey Climate Change Resource Center with support from The Nature Conservancy in New Jersey, the guide compiles current research, case studies, best practices, practical tools, science-based strategies, and funding resources to "inform and empower readers to implement and seek funding for NBS."
Click here to view and download the guide now.
As the guide states, "nature-based solutions (NBS) are defined as actions to protect, sustainably manage, and restore natural and modified ecosystems that address societal challenges effectively and adaptively, simultaneously benefiting people and nature." (IUCN 2024)
Whether you're a municipal planner, community leader, contractor, public- or private-sector professional, or an academic, new to NBS or experienced in large-scale restoration projects, the guide offers value at every level with practical instruction that spans the full project lifecycle, from planning and permitting to funding and long-term monitoring. While the content is tailored to New Jersey's diverse landscapes, the guide's insights and approaches are broadly applicable to regions with similar ecosystems, from Massachusetts to Virginia.
The guide also includes insights on how to address equity considerations and foster meaningful community engagement, helping users implement NBS that are both impactful and inclusive.
Princeton Hydro was proud to contribute technical expertise to this important effort. Our Director of Restoration & Resilience, Christiana L. Pollack, CERP, CFM, GISP, participated on the guide's steering committee, and our team provided informational resources, including content and case studies on invasive species management, wetland and floodplain enhancement, and dam and culvert removal to restore rivers and improve fish passage. These contributions along with those from many other participants, reflect the collaborative nature of the guide and the collective commitment to advancing NBS across the state.
The guide's easy-to-follow format includes four key sections:
Whether you're just beginning to conceptualize a project or deep into project implementation, this guide is an invaluable addition to your toolbox. We encourage you to explore, download, and share it widely! Click here to access the guide now.
On the Paulins Kill, the 100-year old Columbia Lake Dam has almost been completely removed, and fish passage has been restored! Since the first cut was executed on the main dam in August, many exciting advances have been made towards restoring the Paulins Kill back to its natural state. Check out the video below, courtesy of the New Jersey Nature Conservancy Volunteer Drone Team.
Piece by piece, the dam was notched out throughout the fall season and is now completely removed with the exception of the dam apron, the horizontal concrete structure that sits downstream of the dam, and the section of the dam that sits below the riverbed. The part of the dam in the riverbed is now being removed all the way down to three feet under the ground. The full removal is estimated to be complete by mid-March. In mid-August, the first cut was widened to 80 feet, allowing for better management of high flows during storm events, which had been posing a challenge immediately following the first cut.
In late August, the installation of rock vanes at the Brugler Road Bridge began. Rock vanes are engineered, in-stream structures that help to stabilize a channel while enhancing aquatic habitat and movement.
The rock vanes installed at the Brugler Road Bridge site are cross vanes. Cross vanes consist of a set of boulders angled upstream on a river, with another section of smaller rocks placed upstream. The taller sections of the cross vanes deflect the streamflow away from the banks, decreasing scouring effects. Instead, the flow travels over the rock walls and concentrates down the center of the channel, creating a deep and elongated pool in the middle of the stream.
Velocities between the notches in the rock vanes were evaluated using a velocity meter in accordance with the design specifications originally proposed. Based on the U.S. Fish and Wildlife Service fish passage design criteria, velocities in the notches could not be greater than 8.25 feet per second. All of the velocity measurements in this rock vane were below the maximum thresholds, ensuring no blockage of fish passage is made through the vanes.
Since the removal of the dam began, vegetative growth from the natural seedbed of the upper impoundment has been observed (see photo below).
In October, scour protection installation commenced at the Warrington Road Bridge site. After the team conducted geotechnical test pits, they discovered that a concrete scour wall that slopes out to the Paulins Kill was present and deep enough to be able to install rock at the necessary depth. They also found that the existing gabions, caged baskets filled with rock or concrete often used to protect against erosion, were intact and could be left in place. The team installed four (4) feet of riprap under and around the bridge in the riverbed and tied it into the existing grade of the banks.
The original notch in the dam was lowered one foot per day starting in mid-December, reducing water surface elevations down to the apron elevation during the month of January.
To accommodate NJ Fish and Wildlife’s request for animal passage under the I-80 bridges, an area of the previously installed riprap on the northwest abutment wall was flattened out and filled in with river cobble. This path will promote wildlife movement under the bridge as opposed to through the existing tunnel.
Currently, rock vanes are being installed under the I-80 bridges specifically to enhance fish passage. These structures vary slightly from the rock vanes at the Brugler Road Bridge site, as they are designed to slow river flow, helping migrating fish travel upstream and traverse a 5-foot elevation difference in the streambed, much like a fish ladder.
These rock vanes are more than halfway completed and are on track to be finished in time for fish populations to make full use of them. The next steps are to finish the demolition of the dam and the construction of the fish passage rock vanes under the I-80 bridges, plant vegetation throughout the upper impoundment, create a recreational trail through the upper impoundment, and plan for fishing and boating access! Stay tuned for more exciting developments on this incredible project.
Thank you to our project partners: The Nature Conservancy, American Rivers, U.S. Fish and Wildlife Service, and NJDEP Division of Fish and Wildlife Service.
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Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of a dozens of small and large dams in the Northeast. To learn more about our fish passage and dam removal engineering services, visit: bit.ly/DamBarrier.
As one of the Chesapeake Bay’s most productive tributaries and a vital part of Maryland's natural resources, Mattawoman Creek supports some of the largest populations of finfish, amphibians, and birds in the state. A collaborative team of private and public sector entities have designed the "Mattawoman Creek Mitigation Site" in Pomfret, Charles County, Maryland, an effort that will enhance or create 64+ acres of wetlands and restore nearly 3,800 linear feet of this perennial stream. With over 28,500 native trees and shrubs to be planted, this mitigation project will result in 80+ acres of continuous, forested wetland with complex and diverse vegetative communities. It is expected to provide a wide array of habitat to resident and transient wildlife, including birds, reptiles, invertebrates, amphibians and rare, threatened and endangered species.
Unique to this project, Mattawoman Creek Mitigation Site is Maryland’s first-ever Umbrella Mitigation Banking Instrument (UMBI) for federal and other government agency use. A UMBI is the bundling of multiple mitigation banks into one agreement in order to streamline the regulatory approval process, thereby eliminating steps and involving fewer resources. The Maryland UMBI document helps the USAF and other public agencies secure certainty of cost and schedule, facilitate timely permit issuance, and expedite the satisfaction of their permitted requirements for planned capital improvement projects. This approach also maximizes the scale of restoration and resulting land protection and efforts, creating contiguous blocks of habitat with greatly enhanced benefits compared to single, permittee-responsible projects. This precedent was a result of a partnership between United States Air Force (USAF) and Joint Base Andrews (JBA), U.S. Army Corps of Engineers (USACE), Maryland Department of the Environment (MDE), GreenTrust Alliance, GreenVest, and Princeton Hydro.
Projects completed under the UMBI will reduce federal and state workload expediting the regulatory review and issuance of permits by the MDE and USACE. Additionally, projects completed under this UMBI will aid in compliance with the Federal Paperwork Reduction Act where federal regulatory staff can evaluate success and performance issues for multiple permittees at one single habitat restoration or mitigation site. In addition, federal costs are capped, and liabilities are transferred through to GreenVest, the private sector operator, and GreenTrust Alliance, the nonprofit bank sponsor, who will also serve as the long-term steward of sites restored under this program.
Design, engineering/modeling, and permitting of the site was completed by Princeton Hydro and GreenVest under our currently Ecosystem Restoration contract with the USACE. Princeton Hydro also provided an Environmental Assessment and Environmental Baseline Survey, and conducted a geotechnical investigation, which included the advancement of test pits, visual and manual investigation techniques and logging, infiltration testing, laboratory soils testing, and seasonal high-water table estimations.
A wetland water budget was also developed for the proposed wetland creation and restoration to determine if sufficient water is available to establish or reestablish wetlands on the site. It was also used to inform design development including proposed grading and plant community composition. The establishment and re-establishment of wetlands on the site will be accomplished through directed grading, ditch plugging and stream restoration designed to maximize the retention of surface water, floodplain re-connection, and groundwater inputs.
Over 6,000 acres (25%) of the Mattawoman Creek watershed has been protected by public ownership and various conservation and agricultural easements, which, in addition to the Mattawoman Creek Mitigation Site, help ensure that Mattawoman Creek forever remains a high-quality destination for outdoor recreation.
Princeton Hydro specializes in the planning, design, permitting, implementing, and maintenance of tidal and freshwater wetland rehabilitation projects. To learn more about our wetland restoration, creation, and enhancement services, visit: http://bit.ly/PHwetland
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VIDEO: "Columbia Lake Dam when the water level was 18 inches to 2 feet lower" Video courtesy of Matt Hencheck
At the 18th Annual Land Ethics Symposium, which is presented by Bowman's Hill Wildflower Preserve, Princeton Hydro and GreenVest, LLC were honored with the "2018 Land Ethics Award of Merit" for our restoration work at the Mullica River Wetland Mitigation Site.
We teamed up to restore the natural wetland hydrology on a 34-acre parcel of land which was heavily impaired and intensely manipulated for cranberry production over the last century. The area was home to a network of earthen berms surrounding cranberry cultivating bogs, where water onsite was managed through a series of ditches and water control structures set into the berms. The cranberry operation was bordered mostly by an Atlantic white cedar dominated swamp.
"Thank you to Bowman's Hill for honoring this successful wetland restoration," said Mark Gallagher, Vice President of Princeton Hydro. "Through our partnership with GreenVest, we transformed a degraded cranberry bog into thriving emergent and forested wetlands, and restored historic headwater stream channels. These restored wetlands are providing invaluable habitat to a variety of threatened and endangered species in New Jersey, including the Pine Barrens Treefrog and Barred Owl."
While this site was degraded, it still contained four state listed species, including the state-endangered Timber Rattlesnake and the Pine Barrens Tree Frog, making it a priority site for restoration. The presence of these species influenced the design as it included provisions to incorporate habitat elements for these species.
Through the implementation of restoration activities focused on removing the site’s agricultural infrastructure, Princeton Hydro and GreenVest were able to restore a natural wetland system on the site. In addition, the restoration project reconnected the site to its floodplain and re-established a natural stream channel. The expansive, flat and wide floodplain wetland complex of the Alquatka Branch of the Mullica RIver provides floodplain connectivity for relatively frequent storm events and allows for a sustainable floodplain wetland complex in the former cranberry bog cells.
The completed project incorporated a balance of both ecological and human health and safety benefits. Additionally, the project involved innovative restoration techniques that required building consensus among local watershed protection groups and state and regional regulators, including New Jersey Department of Environmental Protection and the New Jersey Pinelands Commission. In the end, the project restored 34 acres of a highly functioning forested wetland/upland complex and reestablished 1,600+ linear feet of historic headwater stream channels.
Princeton Hydro would like to thank Bowman's Hill Wildflower Preserve for both the award and for a organizing another successful Land Ethics Symposium. The conference focused on ways to create low-maintenance, economical and ecologically balanced landscapes using native plants and restoration techniques. Princeton Hydro was a proud "Friends Sponsor" of the event.
To read part two of our Aquatic Organism Passage blog series, click here!
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