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[cat_name] => Stream Restoration [category_nicename] => stream_restoration [category_parent] => 0 ) [queried_object_id] => 41 [request] => SELECT SQL_CALC_FOUND_ROWS ph_posts.ID FROM ph_posts LEFT JOIN ph_term_relationships ON (ph_posts.ID = ph_term_relationships.object_id) LEFT JOIN ph_term_relationships AS tt1 ON (ph_posts.ID = tt1.object_id) WHERE 1=1 AND ( ph_term_relationships.term_taxonomy_id IN (41) AND tt1.term_taxonomy_id IN (10) ) AND ((ph_posts.post_type = 'post' AND (ph_posts.post_status = 'publish' OR ph_posts.post_status = 'acf-disabled'))) GROUP BY ph_posts.ID ORDER BY ph_posts.menu_order, ph_posts.post_date DESC LIMIT 0, 10 [posts] => Array ( [0] => WP_Post Object ( [ID] => 18009 [post_author] => 1 [post_date] => 2025-08-07 19:26:22 [post_date_gmt] => 2025-08-07 19:26:22 [post_content] => 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. Inside the Guide 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 equips readers with:
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.
After 129 years, the Paulina Lake Dam in Warren County is in the final stages of demolition. This project, led by The Nature Conservancy's New Jersey Chapter, is hailed by local advocates as a significant environmental victory. The complete removal of the dam, scheduled from July through September 2024, is the second of three phases of river restoration, and signifies a major milestone in the rehabilitation of the Paulins Kill River, New Jersey’s third-largest tributary to the Delaware River.
On November 24, 2023, a crucial step in the restoration journey was taken with the first notching of the Paulina Dam. This initial step set the stage for the next phase of the dam removal, which is now in full swing. The project, a successful collaboration under the leadership of The Nature Conservancy, funded by NJDEP Division of Fish and Wildlife, and designed and implemented by Princeton Hydro and RiverLogic-Renova Joint Venture, respectively, is progressing toward its goal. The third and final phase will occur in 2025 for adaptive management to complete the finishing touches, including the installation of habitat features to further enhance the biodiversity of this river segment.
Click below to watch a new video showcasing the project's progress. The drone footage captures the project team in action, demolishing the dam, removing sediment upriver, and strategically placing rock check dam to control the flow of sediment as the removal process continues.
Blairstown’s original power source for electricity, the Paulina Lake Dam, located in bucolic Warren County, NJ, has long posed challenges to the river’s health and surrounding communities. Originally constructed to produce hydropower, it has not functioned in that capacity for over 50 years. Its removal is crucial not only for mitigating risks to life and property but also for restoring the natural habitat for native species like brook trout and migratory fish.
Located in bucolic Warren County, New Jersey, The Paulina Lake Dam, Blairstown’s original power source for electricity, has long posed challenges to the river’s health and, after the dam ceased its use as a power source, became a financial and safety liability to Blairstown Township. Its removal is crucial not only for mitigating risks to life and property but also for restoring the natural habitat for native species like brook trout and migratory fish.
This initiative aims to:
The removal of the Paulina Lake Dam is part of a larger restoration plan initiated in 2013 by The Nature Conservancy, which includes the removal of multiple dams along the Paulins Kill River, planting thousands of trees in its riparian zone, and restoration of its headwater Hyper Humus, a glacially created peat bog. This comprehensive effort, involving wetland restoration, land protection, and floodplain reforestation, aims to rejuvenate and sustain the river ecosystem.
Princeton Hydro’s President, Geoffrey M. Goll, PE, highlights the broader impact of these efforts: “The removal of Paulina Lake Dam is not just about dismantling a structure and removing a safety hazard, but paving the way for a renewed riverine landscape, where the flow of life returns to its natural course.”
As we celebrate this major milestone, we look forward to witnessing the continued transformation of the Paulins Kill. This project stands as a testament to the power of collaboration, environmental stewardship, and the unwavering dedication of communities and organizations committed to preserving and restoring our natural landscapes.
Stay tuned for more updates as we continue this exciting journey towards a restored and thriving river ecosystem this fall, and then the finishing touches in 2025! Click here to learn more about the Paulina Lake Dam removal and the broader restoration efforts.
Nestled within the New Jersey townships of Hamilton, Robbinsville, and West Windsor lies Miry Run Dam Site 21—an expansive 279-acre parcel with a rich history dating back to its acquisition by Mercer County in the late 1970s. Originally earmarked for flood mitigation and recreation, this hidden gem is on the cusp of a remarkable transformation, poised to unveil its true potential as a thriving public park.
Central to the revitalization efforts is a comprehensive Master Plan, meticulously crafted by Mercer County Park Commission in partnership with Simone Collins Landscape Architecture and Princeton Hydro. This visionary roadmap encompasses a spectrum of engineering and ecological uplift initiatives, including:
The Master Plan serves as a long-term vision for improvements to the property and will be implemented over multiple phases. In 2021, it was recognized with the Landscape Architectural Chapter Award from the New Jersey Chapter American Society of Landscape Architects, which underscores its innovative and impactful approach to landscape design.
Now, Dam Site 21’s revitalization has begun with a crucial endeavor: the dredging of its 50-acre lake. This process, spearheaded by Mercer County Park Commission in collaboration with Princeton Hydro, aims to rejuvenate the water body by removing accumulated debris, sediment, and invasive vegetation—a vital step towards restoring its ecological balance. Beyond the aesthetic and ecological improvements, dredging enhances accessibility for recreational activities that provide an opportunity to create a deeper connection between the park’s visitors and its beautiful natural landscape.
Based on the bathymetric assessment, which the Princeton Hydro team completed as part of the Master Plan, the dredging efforts are focused on three primary areas: Area 1 is located in the main body of the lake just downstream of Line Road and will generate approximately 34,000 cubic yards of dredged material; Area 2, which has approximately 4,900 cubic yards of accumulated sediment is located in the northeast cove, just north of Area 1; and Area 3, the northwestern cove, entails the removal of approximately 7,300 cubic yards of accumulated sediment.
Before the dredging work could begin, the Princeton Hydro team was responsible for providing a sediment sampling plan, sample collection and laboratory analysis, engineering design plan, preparation and submission of all NJDEP regulatory permitting materials, preparation of the technical specifications, and bid administration. Currently, our team is providing construction administration and oversight for the project.
The journey towards Dam Site 21's revival has been marked by meticulous planning, design, and community engagement spanning several years. With the commencement of dredging operations, the project's vision is gradually materializing—a testament to the dedication of all stakeholders involved. As the first phase unfolds, anticipation mounts for the realization of a vibrant, inclusive public space that honors both nature and community.
As Dam Site 21 undergoes its metamorphosis, it symbolizes not just a physical restoration, but a renewal of collective vision and commitment. Ultimately, Dam Site 21 isn't just a park—it's a testament to the enduring legacy of conservation, community, and the transformative power of restoration.
The significance of Dam Site 21's transformation extends far beyond its recreational appeal. It embodies a commitment to environmental stewardship, with measures aimed at bolstering flood resilience, improving water quality, and nurturing diverse wildlife habitats. By blending conservation with recreation, the project strikes an important balance between creating access for community members to enjoy the space and ecological preservation that puts native plants, critical habitat, and wildlife at the forefront.
To learn more about the restoration initiative and view the Final Master Plan, visit the Mercer County Park Commission’s website. Click here to learn about another one of Princeton Hydro’s recent restoration efforts. And, stay tuned here for more Mercer County Park Commission project updates!
The Horseshoe Mill Dam, built in 1827, served as the first barrier to fish passage on the Weweantic River in Wareham, Massachusetts. For over 150 years, migratory fish were unable to reach their breeding grounds upstream due to this structure. However, thanks to the efforts of the Buzzards Bay Coalition and its project partners, the dam was successfully removed between December 2019 and February 2021. As early as April 2021, migratory fish were seen swimming unimpeded from Buzzards Bay to lay their eggs in freshwater upstream. A true success story!
This blog explores the Horseshoe Mill Dam removal project and celebrates the significant milestone in the recovery of fish populations and the restoration of ecological processes in the Weweantic River.
The Weweantic River winds its way through the picturesque landscapes of southeastern Massachusetts, spanning a length of 17.0 miles. This land is the traditional territory of the Wampanoag/Wôpanâak tribes. Derived from the Wampanoag language, Weweantic means "crooked" or "wandering stream."
Originating from the wetlands in Carver, the river flows in a southerly direction meandering through swampy birch and maple forests in Middleborough and Rochester. Eventually, it empties into a Buzzards Bay estuary near the mouth of the Sippican River in Wareham. The river's watershed covers approximately 18,000 acres, with numerous cranberry bogs situated in its upper sections.
Although the Weweantic River historically teemed with fish, the presence of the Horseshoe Mill Dam posed an obstacle to fish passage. The dam, spanning the Weweantic River at the head-of-tide, was built in 1827 to support a metal forge mill. Although it was once part of the infrastructure that supported Wareham’s economy, it had been decommissioned and left crumbling for decades. The defunct dam restricted to tidal inundation, hindered the migration of important fish species, and impacted riverine ecological processes.
The Weweantic River is the largest tributary to Buzzards Bay and provides 20 percent of all freshwater flow into Buzzards Bay. The meeting of salinity and nutrients through the tidal flow creates a vibrant ecosystem. It supports diverse communities of wetland species and a variety of non-migratory and migratory fish species, including river herring, white perch, and American eel. It is also home to the southernmost population of rainbow smelt in the United States, marking a significant change from a century ago when rainbow smelt were found as far south as the Chesapeake Bay. In the 1960s, smelt populations were even present in the Hudson River in New York.
Further highlighting the ecological significance of the Weweantic River and its surrounding watershed are the unique tidal freshwater wetland plant communities. The wetland areas surrounding the Horseshoe Mill Dam site contained two rare wetland plants, Parker's Pipewort (Eriocaulon parkeri) and Pygmyweed (Crassula aquatica), both of which are designated as priority habitats for rare species.
Additionally, situated along the shore of Buzzards Bay and the Weweantic River is the Cromeset Neck & Mark's Cove Marsh Wildlife Sanctuary. The 47-acre wildlife sanctuary consists of three separate parcels within one mile of each other. Salt marsh comprises most of the wildlife sanctuary, and the property also contains approximately six contiguous acres of coastal woodland.
The Horseshoe Mill Dam removal project involved several phases to achieve its restoration goals.
An inspection of the dam, conducted in 2009, rated its condition as unsatisfactory and noted significant concrete deterioration and erosion. The dam also included a former concrete-walled mill race that was in a state of disrepair, with collapsed walls and obstructed channels. The Buzzards Bay Coalition acquired the 10-acre Horseshoe Mill Dam property in 2012 to preserve it, provide public access, and pursue river restoration.
In 2016, the Buzzards Bay Coalition contracted Princeton Hydro to provide an Alternatives Analysis for the Weweantic River restoration project and a Fish Passage Feasibility Study for the dam. The analysis included a thorough site investigation, historical data review, sediment evaluation, hydrologic and hydraulic analysis, and ecological assessment. The five options considered in the analysis were:
The analysis ultimately helped the Buzzards Bay Coalition determine that a complete dam removal offered the most favorable ecological and economic outcomes.
Princeton Hydro, contracted by the Buzzards Bay Coalition, provided site investigation, engineering design, permitting, and construction oversight services for the dam removal. With funding from the Bouchard 120 Natural Resource Damage Trustee Council and collaboration with various agencies, including the U.S. Fish and Wildlife Service and NOAA, the dam removal commenced in December 2019 and was successfully completed in early 2021. Just months later in April 2021, for the first time in 150+ years, migratory fish were once again spotted swimming unimpeded from Buzzards Bay to lay their eggs in freshwater upstream.
Since the completion of the dam removal, Buzzards Bay Coalition Restoration Ecologist Sara da Silva Quintal has been consistently visiting the site and monitoring the positive changes taking place. Her observations include vegetation changes, signs of migratory fish spawning, and the geomorphic evolution of the landscape. She shared a series of Nearmap images that demonstrate how the landscape is positively adjusting to the barrier removal:
The completion of the Horseshoe Mill Dam removal project marks a significant achievement in the restoration of fish passage and the preservation of ecological function in the Weweantic River. Through the collaborative efforts of the Buzzards Bay Coalition, government agencies, and project partners, migratory fish can now freely swim upstream to their breeding grounds.
The restoration effort rejuvenated more than three miles of the Weweantic River and restored migratory fish passage. The dam removal enhanced riverine, wetland, and tidal habitat critical to a diverse group of aquatic, wildlife and plant species. It allowed for the natural extension of upriver habitat for two rare tidal plant species, ensuring their long-term survival. The restoration work also enhanced public access to the area by increasing walking trails and constructing canoe/kayak launches, promoting recreational opportunities, and fostering a deeper connection between people and the river.
In an article written by Kasey Silvia in November 2021, the Vice President for Watershed Protection at Buzzards Bay Coalition, Brendan Annett, was quoted as saying, “Removing this dam has immediately improved the natural functions of the Weweantic, undoing many years of environmental damage and it has already begun to bring the river back to life.”
The success of this project serves as a testament to the importance of collaborative conservation efforts in safeguarding and restoring our natural resources.
In the late 1920s, the U.S. government began allocating funds for road construction in U.S. national forests. This led to hundreds of thousands of culverts being built and installed across the country for the purpose of moving water quickly and efficiently underneath the roadways to prevent flooding, minimize erosion, and provide pathways for stormwater.
However, culverts have had an unintended and significant consequence: they block the migration routes of some fish and aquatic organisms.
Culverts that are undersized, improperly placed, or designed with smooth featureless surfaces can impede or totally block fish and aquatic species from passing. Culverts with extremely high velocity flows make it incredibly difficult for aquatic organisms to navigate upstream, and extremely low velocity flows make it hard for fish to pass in either direction. The high-velocity flows can erode the stream channel immediately downstream of the culvert, which can leave the culvert pipe perched. This elevation above the water channel makes it impossible for organisms to pass through. Debris can also collect in the culvert, not only blocking fish passage, but water as well.
In addition to blocking the upstream passage of fish and other aquatic species, some culverts disrupt the normal stream movements of some macroinvertebrates, which are key components of these stream ecosystems, an important food source to countless species, and play a critical role in the cycling of energy and nutrients throughout stream ecosystems. Disruptions to the movement and dispersal of stream macroinvertebrates can reduce available habitat, lead to genetic isolation of some populations, and cause extirpation of critical species. When populations splinter, it causes a reduction in genetic diversity, which can lead to the spread of more invasive species and many other ecological issues.
While culverts serve an important function in road construction and flood prevention, their impact on aquatic organisms must be taken into consideration. Finding solutions that both allow for efficient water flow and enable safe aquatic migration is crucial in preserving the health of our waterways and their ecosystems.
A shift in the 1980s recognized the importance of redesigning road-stream crossings for several reasons, including restoring aquatic organism passage and maintaining flood resilience. Between 2008 and 2015, U.S. Forest Service (USFS) partnered with more than 200 organizations in the Legacy Roads and Trails Program to replace 1,000+ culverts across the country. The aim of the program was to upgrade culverts to emulate natural streams and to allow fish and wildlife to pass more naturally both upstream and downstream.
Replacing culverts with structures that better facilitate the movement of both water and aquatic organisms has benefits beyond restoring critical ecosystems and improving biodiversity. Ecological restoration creates jobs, stimulates outdoor recreation and local economic activity, and generates long-term economic value.
Princeton Hydro has a strong history in designing connectivity-friendly road-stream crossings and restoring/replacing outdated culverts. Our team of engineers and scientists has been directly involved with hundreds of stream and ecosystem restoration projects throughout the Northeast.
For several years, Princeton Hydro has partnered with NY-NJ Harbor & Estuary Program (HEP) to plan and design for aquatic connectivity through climate-ready infrastructure. Created by the U.S. Environmental Protection Agency (USEPA) at the request of the governors of New York and New Jersey, HEP develops and implements plans that protect, conserve and restore the estuary, and aquatic connectivity is a key focus area for HEP and its partners.
Most recently, HEP partnered with Princeton Hydro to address hydraulic capacity issues at priority road-stream crossings in New Jersey’s South River and Lower Raritan River watersheds. The Princeton Hydro team developed a 30% engineering plan for a priority road-stream crossing – the Birch Street crossing over the Iresick Brook in Old Bridge, NJ.
Iresick Brook is upstream from Duhernal Lake, located at the end of the free-flowing South River, which feeds into the Raritan River, and ultimately flows into Raritan Bay. Duhernal Lake is dammed at the outlet so there is little to no connectivity downstream from the Iresick Brook sub-watershed. The watershed is highly dendritic (meaning the drainage pattern follows a tree-like shape) with many small streams running through it, some of them ephemeral.
The Iresick Brook 5 (IB5) culvert, located in Old Bridge Township, New Jersey, is an undersized double culvert in poor condition with an eroding streambank. This culvert was chosen as a restoration priority primarily due its inadequate sizing (both pipes are only 3-feet in diameter). The outdated infrastructure blocks the passage of fish and other aquatic organisms, and it can only accommodate a 50-year storm event.
Once the IB5 culvert was identified as the priority site, Princeton Hydro completed a site investigation, which included a geomorphic assessment, site observations, and simplified site survey of the channel alignment, profile, and cross sections both upstream and downstream of the culvert.
At the time of the survey, flow was only a couple inches deep in the channel and incredibly slow-moving, especially in the upstream reach. Despite the low flow at the time of the survey, during storm events, the stream experiences extremely high velocities. The undersized culvert creates hydraulic constriction and subsequently a velocity barrier that prevents passage. Additionally, when the high-flow stream water is forced through the small pipes, it creates a firehose effect, which has led to the formation of a 60-foot-long scour hole at the culvert outlet. Substrate from the scour hole has been washed downstream, forming an island of large sand and small gravel.
Approximately 155 feet upstream of the culvert is a channel-spanning v-notch weir comprised of a combination of sheet pile and timber. The weir appears to be a historical stream gauge that is highly degraded and creates an artificially perched channel. The upstream channel also contains woody debris, which gets caught at the culvert, blocking water flow and organism passage.
For the design process, Princeton Hydro used the USFS Stream Simulation Design, an gold-standard ecosystem-based approach for designing and constructing road-stream crossings that provide unimpeded fish and other aquatic organism passage through the structure. The Stream Simulation, a required standard on USFS road projects, integrates fluvial geomorphology concepts and methods with engineering principles to design a road-stream crossing that contains a natural and dynamic channel through the structure so that fish and other aquatic organisms will experience no greater difficulty moving through the structure than if the crossing did not exist.
The design also incorporated utility constraints (gas line, sewer line, drinking water main, and stormwater outlet), a longitudinal profile assessment, channel capacity and slope analysis, and a simplified hydrologic & hydraulic assessment.
Ultimately, Princeton Hydro recommended that HEP replace the existing culvert with a Contech Precast O-321 culvert, or similar alternative. The proposed design increases the culvert opening area and allows for significant increases in flow capacity. This culvert replacement project has the potential to reduce local flood risk and restore aquatic organism passage to the reach of Iresick Brook.
Aquatic connectivity is crucial for improving healthy aquatic ecosystems and managing severe storms and flooding. Increases in rainfall due to climate change makes investing in these improvements even more of a growing priority. With so many culverts in place, it can be difficult to know which culvert restoration projects to prioritize.
We worked with HEP to create a toolkit for addressing problematic road-stream crossings. The easy-to-use matrix helps to prioritize potential projects and identify solutions for problem culverts and relative cost solutions.
The toolkit was just recently released to the public with the hope that it will be used as a template to promote the development of more resilient and environmentally-friendly infrastructure.
Click here to get more info and download.
If you've ever observed orange water in a river or stream after a dam has been removed, you may have been surprised by the strange color. This phenomenon is caused by iron oxide floc. But what exactly is iron oxide floc and how does it form?
Iron oxide, also known as rust, is a common compond found in nature. When it is dissolved in water, it takes on a reddish-brown color. Although the color can be alarming, iron oxide floc is relatively harmless and is actually a sign of the waterway returning to a more natural state.
The formation of iron oxide floc begins with the seepage of anaerobic groundwater through the embankment of a dam. The groundwater behind a dam often contains high levels of iron and is anaerobic (low in oxygen) because it is not exposed to the air and therefore does not have access to oxygen. When this anaerobic water reaches the other side of the dam and mixes with the aerobic surface water, the oxygen in the surface water reacts with the iron in the groundwater, forming iron oxide floc.
The orange color of the water is a result of the floc suspending in the water column and/or settling to the bottom of the waterway, creating a layer of orange sediment. In these situations, the iron oxide floc is only a temporary effect of the dam removal, not harmful to the environment, and will eventually be washed away by natural processes. As the waterway adjusts to its new, natural flow, the iron oxide floc will eventually disappear completely.
While the orange color may be surprising to see, it is a sign that the waterway is returning to a more natural state, leading to the water quality and habitat improvements achieved by dam removals. Removing outdated dams and restoring the natural flow of rivers has myriad benefits, including reconnecting river habitats that benefit fish and wildlife; reducing flood risk to surrounding communities; and promoting a healthier and more diverse ecosystem.
Princeton Hydro has designed, permitted, and overseen the removal of dozens of small and large dams throughout the Northeast. Click here to learn more about our dam engineering and removal services. And, if you're interested in reading about some of the dams we've removed in the Lehigh River Valley, click below:
According to American Rivers, “more than 90,000 dams in the country are no longer serving the purpose that they were built to provide decades or centuries ago.” As these dams age and decay, they can become public safety hazards, presenting a failure risk and flooding danger. Dams can also be environmental hazards, blocking the movement of fish and other aquatic species, inundating river habitat, impairing water quality, and altering the flow necessary to sustain river life.
Removing nonfunctional, outdated dams has myriad ecological benefits. Dam removal can improve water quality, restore a river back to its natural flowing state, reconnect river habitats that benefit fish and wildlife, and significantly increase biodiversity for the surrounding watershed.
For over a decade, Princeton Hydro has partnered with Wildlands Conservancy to remove dams in the Lehigh River Valley. Wildlands Conservancy, a nonprofit land trust in eastern Pennsylvania, works to restore degraded stream and wildlife habitat with a primary focus on Lehigh Valley and the Lehigh River watershed, which is a 1,345 square mile drainage area that eventually flows into the Delaware River.
Wildlands Conservancy contracted Princeton Hydro to design and permit the removal of two dams on the Little Lehigh Creek. Although it is referred to as the “Little Lehigh,” the 24-mile creek is the largest tributary of the Lehigh River. The dam removals restored the natural stream system, which hadn’t flowed freely in over a century.
Princeton Hydro also worked with Wildlands Conservancy to remove several barriers and three consecutive low-head dams on Jordan Creek, a tributary of the Little Lehigh Creek. Jordan Creek arises from a natural spring on Blue Mountain, and eventually joins the Little Lehigh in Allentown before flowing into the Lehigh River. It drains an area of 75.8 square miles.
Collectively, these dam and barrier removal projects on the Little Lehigh and Jordan Creek reconnected 15+ miles of river; restored fish passage; improved aquatic connectivity, fisheries, and benthic macroinvertebrate and wildlife habitats; reduced nonpoint source stormwater pollution; improved water quality; addressed vulnerable infrastructure; enhanced climate resiliency; and stabilized and restored the creeks’ channels and banks.
Building upon the successes of the Little Lehigh and Jordan Creek barrier removals, Princeton Hydro is again partnering with Wildlands Conservancy to remove three consecutive dams on Bushkill Creek in Easton, PA. The dam removal projects, which are slated for 2023, are part of a large-scale effort, involving a significant number of community and municipal partners, focused on restoring Bushkill Creek and the surrounding watershed.
The Bushkill Creek is a 22-mile long limestone stream that is designated as a “high quality, cold-water fishery.” It supports healthy populations of trout, and is treasured by anglers and the surrounding community as an important resource in an urban environment, spanning several boroughs and townships, eventually flowing into the Delaware River at Easton.
Environmental protection and restoration is a key goal of removing the dams. Removing these barriers will allow important migratory fish species to reach their spawning grounds once again, which has numerous and far-reaching ecological benefits. The project work also includes stabilizing the streambank, planting, and expanding riparian buffers, planting native trees and shrubs to filter runoff, and installing in-stream structures to restore fish habitat.
Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of over 60 of small and large dams in the Northeast. To learn more about our fish passage and dam removal engineering services, click here. To learn more about Wildlands Conservancy, click here.
For episode three of Stroud Water Research Center's 2022 Science Seminar Series, Michael Hartshorne, Director of Aquatics at Princeton Hydro (and former Stroud Center intern), gave a presentation about the ecological status of the Schuylkill River and shared the story of a yearlong community science project that included a volunteer survey and scientific water quality assessment. Stroud Center's Science Seminar lecture series, which provides an opportunity for the public to learn more about the issues that matter to them, has been running for over a decade. It also gives the public access to some of the world’s leading freshwater scientists and educators and the chance to learn how watershed science and education are tackling water-related challenges.
As described in Michael's presentation, the project, which included four phases, was implemented through a partnership between the Schuylkill River Greenways, Berks Nature, Bartram’s Garden, The Schuylkill Center for Environmental Education, Stroud Center, and Princeton Hydro.
First, to understand local perceptions of the river, investigators conducted a community survey of more than 300 residents from Berks, Chester, Montgomery, and Philadelphia counties. Despite a majority of respondents reporting that they care about the river, many also reported concerns about trash and litter and whether the river is clean and safe enough for activities like swimming and fishing. This insight was used to drive the priorities for the in-depth water quality monitoring assessment and inspired the launch of a new Community Science trash monitoring program.
In June, the group launched an interactive ArcGIS StoryMap webpage that reveals the local perceptions of the Schuylkill River and aims to connect residents and communities with the Schuylkill River and encourage engagement with this special resource.
In October 2021, the largest stream restoration in Maryland was completed. Over 7 miles (41,000 linear feet) of Tinkers Creek and its tributaries were stabilized and restored.
The project was designed by Princeton Hydro for GV-Petro, a partnership between GreenVest and Petro Design Build Group. Working with Prince George’s County Department of the Environment and coordinating with the Maryland-National Capital Parks and Planning Commission, this full-delivery project was designed to meet the County’s Watershed Implementation Plan total maximum daily load (TMDL) requirements and its National Pollutant Discharge Elimination System Municipal Separate Storm Sewer System (MS4) Discharge Permit conditions.
Today, we are thrilled to report that the once highly urbanized watershed is flourishing and teeming with life:
We used nature-based design and bioengineering techniques like riparian zone planting and live staking to prevent erosion and restore wildlife habitat.
10,985 native trees and shrubs were planted in the riparian area, and 10,910 trees were planted as live stakes along the streambank.
For more information about the project visit GreenVest's website and check out our blog:
Welcome to the latest edition of our Client Spotlight series, which provides an inside look at our collaboration, teamwork, and accomplishments with a specific client.
Today, we’re shining the spotlight on the Seatuck Environmental Association. Seatuck Environmental Association is a 501c3 nonprofit based in Islip, New York. They work on wildlife conservation and nature education across Long Island. The organization advocates for wildlife and advancing conservation projects, engages community scientists in wildlife research, and offers environmental education opportunities for Long Islanders of all ages.
For this Client Spotlight, we spoke with Seatuck’s Conservation Policy Advocate Emily Hall via zoom:
Particularly in our conservation work, we really try to stay niche. We specifically focus on restoring and protecting Long Island’s wildlife and environment. We advocate for wildlife, advance restoration projects, conduct surveys, educate public officials, host workshops, lead coalitions and pursue a host of other approaches to promote wildlife conservation and habitat restoration.
Seatuck is really unique because we're one of the only environmental organizations that works island-wide and isn’t part of a national organization. This really gives us the opportunity to stay focused on Long Island’s wildlife and environment, and dive into a lot of different wildlife protection efforts as well as habitat restoration projects. We also offer nature-based education programs all the way from pre-k to professional teacher training.
We’ve been working with Princeton Hydro since 2018. Seatuck was awarded the NYSDEC Division of Marine Resources Grant for Tributary Restoration and Resiliency to design a fish passage at the dam intersecting Mill Pond and Bellmore Creek. We contracted Princeton Hydro to design the fish passage options. Read more about the project here:
As an organization, it’s very important for us to collaborate with the community on projects and initiatives, and to understand the perspectives of all the different stakeholders involved. For the Bellmore Creek Fish Passage Project, we brought together environmental organizations, community members and the dam owners. We began by holding in-person meetings and site visits in order to provide education around the site’s history and the project goals, and give everyone a chance to hear each other’s feedback in real-time. Then COVID forced us to go virtual so we hosted a community webinar and developed an online survey. We collected a lot of valuable feedback that we were able to bring back to the dam owners to help them make the best decision possible.
Meeting with all the different stakeholders and talking to them about the project is probably one of my most rewarding parts of the project. Educating people on why these diadromous fish are important and helping them understand the different benefits of a fish passage is very important to me and incredibly rewarding.
Princeton Hydro has been a fantastic partner through the Bellmore Creek Project. We look forward to working with Princeton Hydro in the future and supporting our efforts to look at different fish passage projects, potentially dam removals, and related alternative assessments. For Bellmore Creek, Princeton Hydro provided valuable insights as to the different types of fish passage options and helped to identify the best option for our community. We’ll hopefully continue this partnership and work together to restore the ecological health of more coastal rivers and streams.
Thanks to Seatuck Environmental Association and Emily Hall for being a great project partner and participating in this Client Spotlight. To learn more about Seatuck, visit their website.
Click here to read a previous edition of our Client Spotlight blog series, which features Medford Lakes Colony in New Jersey:
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