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.
We are thrilled to announce the newest addition to our fleet: The Marsh Master® 2MX-KC-FH! This multi-functional, eco-friendly, and fully amphibious machine is specifically designed to work in wetland environments with minimal disruption to the delicate ecosystem.
One of the Marsh Master®'s primary roles is combating invasive and nuisance plant species, including the notorious non-native Phragmites australis, also known as Common Reed. Utilizing its innovative leveling and cutting mechanisms, this powerhouse of a machine efficiently knocks down and chops up sprayed or winter-weakened vegetation. Equipped with two powerful rotary blades, it effortlessly cuts through dense underbrush and tall marsh grasses, effectively controlling invasive weeds and problematic plant growth.
"We are committed to offering more non-chemical alternatives for aquatic invasive species control. The Marsh Master® 2MX-KC-FH is the second marsh buggy in our fleet," said Geoffrey M. Goll, President of Princeton Hydro. "This model is larger and more powerful, allowing us to cover more ground in a shorter period of time. Adding this machine to our fleet is an important investment in achieving our firm's environmental stewardship goals."
What sets the Marsh Master® apart is its versatility and low environmental impact. With its lightweight construction and advanced weight distribution system, it exerts low ground pressure and boasts high floating capacity. This allows the Marsh Master® to operate seamlessly on water, in deep or shallow depths, and on dry land without disturbing sensitive environments like nature preserves, wetlands, and canal banks. Its highly maneuverable design ensures easy passage through narrow channels and around hazards, making it the ideal choice for a wide range of applications.
But the Marsh Master® is not just a one-trick pony. With a wide array of tools and accessories, it can perform a variety of functions, from weed cutting and harvesting to debris removal to excavation to soil sampling.
During a recent project in Middlesex County, we put the Marsh Master® to the test to clear an area overrun with Phragmites australis. These invasive weeds not only create dense thickets unsuitable for native fauna but also outcompete local vegetation, leading to a decrease in plant diversity. Thanks to the Marsh Master®'s efficient cutting and rolling capabilities, we were able to expose the marsh plain and get it ready for planting of native vegetation in the Spring. This is just one example of how the Marsh Master is making a tangible difference in restoring delicate ecosystems.
Through a combination of prevention, early detection, eradication, restoration, research and outreach, we can protect our native landscapes and reduce the spread of invasive species. Learn more about our invasive species removal and restoration services.
A wetland is a unique ecosystem that is permanently or seasonally saturated by water, including swamps, marshes, bogs, vernal pools, and similar areas. They provide water quality improvement, flood protection, shoreline erosion control, food for humans and animals, and critical habitat for thousands of species of aquatic and terrestrial plants, aquatic organisms, and wildlife.
Princeton Hydro is regionally recognized for its capabilities in the restoration of freshwater and saltwater wetland ecosystems. Our ecologists also regularly conduct wetland delineations. A wetland delineation, a requirement of most permitting efforts, is the field work conducted to determine the boundary between the upper limit of a wetland and the lower limit of an upland thus identifying the approximate extent and location of wetlands on a requested site.
For this edition of our “A Day in the Life” blog series, we join Environmental Scientist Ivy Babson and Regulatory Compliance & Wildlife Surveys Project Manager Emily Bjorhus, PWS out in the field for a wetland delineation.
Most commonly, wetlands are delineated based on the Routine Onsite Determination Method set forth in the Federal Manual Identifying and Delineating Jurisdictional Wetlands (FICWD 1989) with supplemental information provided by the applicable United States Army Corps of Engineers’ (USACE) regional supplement manual.
USACE’s “three-parameter” approach defines an area as a wetland if it exhibits, under normal circumstances, all the following characteristics:
Ivy and Emily begin by coordinating with the client to ensure they’ve been granted site access approval.
They then perform a comprehensive desktop analysis of the project site, identifying existing features like wetlands, open waters (streams, lakes), and potential hydric soils. This involves utilizing resources like USFWS's National Wetland Inventory Mapper, the U.S. Geological Survey's SSURGO Soils Survey, and, for New Jersey-based delineations, NJDEP's GeoWeb. The desktop review also allows Ivy and Emily to assemble the proper safety gear and create a Model Health & Safety Plan (HASP). A HASP must always be prepared before the field work begins.
It's always important to make a plan for the project. If we are delineating a large property, it might take several days to traverse, and each day, the weather might be different. So planning ahead, but also being prepared for unexpected changes, will make the day go that much smoother. And, as part of the HASP, we must identify important points of contact and know where the closest hospital is in case of a serious emergency. So, reviewing this information and planning ahead prior to heading into the field is a very important step in the process.
While wetland delineations can be conducted any time of the year, they are best conducted during the “growing season” when soil temperatures are above the biologic zero and vegetation is easily identifiable by leaves, inflorescence, or other unique identifying characteristics that would otherwise be difficult to identify during the winter months.
Ivy and Emily begin by locating known (mapped) wetland or waterbody features and writing a list of all plants observed on-site. They maintain the plant list throughout the day.
If, during the desktop review, they find a mapped wetland or stream, they walk there first to determine if wetlands are actually present. Even if a wetland is mapped on a database, it may not actually exist for various reasons. On the flip side, even if a site is not mapped as containing wetlands, the site could very well contain them. As such, the wetland delineation determines exactly what is on-site and supplements the desktop review.
As mentioned above, a wetland delineation considers three determining factors: 1) vegetation, 2) soils, and 3) hydrology. While on site, Ivy and Emily must identify hydrophytic vegetation, take soil borings, and look for wetland hydrology to identify whether a wetland is present or not.
Wetlands are dominated by hydrophytes which are plants that can grow in water or on a substrate that is at least periodically deficient in oxygen because of excessive water content and depleted soil oxygen levels.
The USACE and NJDEP definition of hydrophytes is based on the USFWS classification system. In general, any plant species that is found growing in wetlands more than 50% of the time is considered a hydrophyte. These plants include those classified by the USFWS as “facultative," “facultative wetland," or “obligate."
As a wetland delineator, it is important to possess strong plant identification skills and an eye for recognizing various ecological plant communities, which are groups of plants that share a common environment and environmental requirements. They are often defined by dominant plant species.
Once Ivy and Emily identify the hydrophytic plant community, they determine what type of ecological community they are in (e.g., freshwater forested wetland, estuarine scrub-shrub wetland, or freshwater tidal emergent marsh). Today, they are in a freshwater forested wetland, which means Ivy and Emily must now assess each stratum of the forested wetland by writing down the species and associated percent species cover.
To accurately describe the vegetation at each sampling point, we collect data on each horizontal strata or layer. Vegetative strata for which dominants are determined include (1) tree (> 5.0 inches diameter at breast height (DBH) and 20 feet or taller); (2) sapling (0.4 to <5.0 inches DBH and <20 feet tall); (3) shrub (usually 3 to 20 feet tall including multi-stemmed, bushy shrubs); (4) woody vine; and (5) herb (herbaceous plants including graminoids, forbs, ferns, fern allies, herbaceous vines, and tree seedlings). They repeat this process for each representative wetland.
Next, Ivy and Emily look for the upland plant community that is directly upslope of the wetland and make note of the proximity to the wetland, repeating the same vegetation documentation process.
Ivy and Emily must determine whether the soils within the hydrophytic plant community are hydric. Hydric soils are defined as soils that are saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions in the upper part. Hydric soil indicators are features in the soil that predominantly form by biogeochemical processes in a saturated and anaerobic environment and result in the accumulation of loss of iron, manganese, sulfur, or carbon compounds.
Emily uses a soil auger to collect a sample of the first 6 - 12 inches of soil where the most significant parts of a hydric soil would be occurring.
Once Ivy and Emily identify that the soil is indeed hydric, Ivy uses her Munsell soil color book to determine the value of the soil and each hydric soil indicator.
They also document additional characteristics of each soil layer: Is it loam, silty loam, sand, sandy loam, silt, muck, clay, clayey loam, etc.? What is the percentage of rocks, plant roots, or other organic matter in each layer? What is the percentage of redoximorphic features of each layer and are they faint or prominent?
Each layer of the soil profile, which is typically documented to a depth of at least 18 inches, is sectioned out and thoroughly described.
The identification of positive indicators of wetland hydrology includes direct observation of indicator groups, such as the observation of surface water or saturated soils, evidence of recent inundation, evidence of current or recent soil saturation, and evidence from other site conditions or data. Each group contains several indicators, which are classified into categories known as “primary” or “secondary” indicators.
To positively identify the area as being a wetland, at least one primary wetland indicator (from any group) or at least two secondary wetland indicators (from any group) must be present.
Additionally, for an area to be designated as a wetland, the area must have the presence of water for a week or more during the growing season. Areas with wetland hydrology characteristics are those where the presence of water has an overriding influence on characteristics of vegetation and soils due to anaerobic and reducing conditions, respectively.
Today, Emily and Ivy observe a depression (secondary) along with a few inches of standing water (primary), water-stained leaves (primary), frogs hopping around (primary), and moss trim lines on the tree trunks (secondary). All signs point to a forested wetland; however, there is more to consider.
Ivy and Emily’s soil boring assessment showed that the soils within the top 12 inches of the soil surface were saturated (primary) and bright orange streaks were visible along the plant roots, which they documented as oxidized rhizospheres along living roots (primary). Because they identified more than one primary and two secondary wetland indicators, they can confidently delineate the wetland.
Now that Ivy and Emily established that a wetland is present, they must find the boundary of the upland. They are now looking for the absence of hydrophytic vegetation, hydric soils, and positive indicators of wetland hydrology as well as the dominance of upland ecological plant communities. The same analysis and documentation process they completed for the wetland area is also required for the upland area.
Once they locate the boundary, they flag the wetland line, labeling the flagging with the wetland nomenclature and either hanging it or pinning it into the ground.
While the description sounds relatively simple, finding the boundary between a wetland and upland can be tricky and time consuming. For example, there may be some hydrophytic vegetation growing within an upland and there may be one secondary positive indicator of wetland hydrology, but hydric soils are missing. To positively classify an area as a wetland, a slam dunk on all three parameters is required.
Ivy and Emily must also delineate waterbodies concurrent with wetlands. Waterbodies may include, but are not limited to, streams, rivers, lakes, and ponds. To delineate a waterbody, they hang labeled flagging along the waterbody’s top of bank or its ordinary high water mark. Throughout this process, they take pictures to document the existing waterbody conditions.
Once the wetland delineation is complete, Ivy and Emily draw out a field sketch that depicts the approximate extent and location of the wetland and waterbody boundaries with their respective nomenclature.
Depending on the project scope, the field sketch is either submitted to a Professional Licensed Surveyor who will then visit the site to survey each wetland and waterbody flag, or Ivy and Emily will return to the site to survey each flag with a survey-grade GPS. Once the survey is complete, Ivy and Emily will conduct a final review of the plans to ensure accuracy.
If requested, they will also prepare a wetland delineation report, which outlines the delineation method, findings, results, and thorough description of each wetland and its soils, hydrology, and vegetation.
“Wetland delineations aren’t for the faint of heart,” said Ivy. “At the end of the day, you might emerge from a dense stand of Phragmites garnering strange looks from passersby with muck smeared on your face, sticks and leaves poking out of your hair, a belly full of mosquitos that you might have accidentally swallowed, and fingernails stuffed with dirt. However, there isn’t any other type of field that I would rather be in. As a wetland delineator, I can access environments that most people would steer clear of and, as a result, I get to see things that I wouldn’t get to see anywhere else. I get to improve my plant identification skills and expand my knowledge of how wetlands function as an ecosystem.”
Emily Bjorhus is a Project Manager that specializes in environmental regulatory compliance, ecological services and wildlife surveys. She leads federal, state and local environmental permitting processes, NEPA compliance and documentation, Endangered Species Act Section 7 consultations, and Clean Water Act Section 404(b)1 analyses. Mrs. Bjorhus is a certified Professional Wetland Scientist.
As an Environmental Scientist, Ivy Babson regularly conducts wetland delineations and monitoring, flora/fauna surveys, water quality sampling, fishery surveys, permitting, and regulatory compliance for a series of projects. She earned her Wetland Delineation Certification from Rutgers University. Ivy graduated from the University of Vermont in 2019 with a B.S. in Environmental Science with a concentration in Ecological Design, and minor in Geospatial Technologies.
Over 40 years ago, Mercer County purchased 279 acres of flood-prone land along Miry Run as part of a restoration and flood mitigation initiative. Mercer County’s Master Plan, approved in 2020, goes above and beyond the original vision, proposing considerable improvements to the area, including 34 acres of reforestation, 64 acres of new meadows, 19 acres of vernal pools, and 7.9 miles of walking trails. Mercer County Park Commission contracted Princeton Hydro and Simone Collins Landscape Architecture to develop the plan.
Today, we are thrilled to announce that the Miry Run Ponds Master Plan was awarded the 2021 Landscape Architectural Chapter Award from the New Jersey Chapter American Society of Landscape Architects (NJASLA).
Each year, the NJASLA Professional Awards honor the best in landscape architecture in the region. Only one Chapter Award is given annually for exceptional performance in any category, as determined by a unanimous vote of the jury members. This year’s jury was composed of distinguished members from the Oregon ASLA Chapter. There were 19 total projects entered into the 2021 competition.
The gap between the current condition and the huge potential pushed the Mercer County Park Commission to contract Princeton Hydro and Simone Collins Landscape Architecture in 2018 to assess the land area and propose a concept plan to enhance the area and create recreational lake activities.
Beginning in December 2018 and throughout the course of 2019, the project team implemented the necessary measures to fully assess the status of the expansive property. Applying expertise in science-based assessment and evaluations, our aquatic ecologists and environmental scientists performed:
These evaluations were conducted in order to better understand the existing site and area conditions, to assist in the development of the site plan, and for future incorporation into Mercer County’s Draft Master Plan.
In addition, our project team facilitated focus groups with local municipalities, residents, interest groups, and County stakeholders to seek their input and to report the site evaluation findings. In partnership with Mercer County, the team led many public community meetings that served as a platform for discussion about the project and conceptual site designs. The meetings helped to inform the process through collaboration and determine how best to manage the site moving forward in order to meet the needs of the community and future generations.
In November of 2019, a draft master plan was released, followed by a 60-day public comment period. The commission hosted a series of public meetings to solicit input for potential improvements to the park. Having reviewed and considered all comments, the Park Commission’s Steering Committee and team of expert consultants were able to finalize the plan, which focused on environmental stewardship and education paired with passive land and water-based activities.
The Master Plan was then presented to the Park Commission for review and approved in 2020.
The improvement plans comprises:
Of the total Miry Run Ponds land area, only 17 acres, or approximately 7.4 percent of the site, would be disturbed for trails, parking and other park visitor facilities. The site’s valuable natural features will be augmented through the establishment of 34 acres of new forest and 64 acres of native meadow.
The Master Plan serves as a long-term vision for improvements to the property and will be implemented over multiple phases. The construction of major park improvements is projected for 2022-2023.
To view the Final Master Plan, visit the Park Commission’s website. To learn more about the NJASLA and see a complete list of 2021 award winners, go here.
Located in Hamilton Township, New Jersey, Mercer County's John A. Roebling Memorial Park offers residents in the surrounding area a freshwater marsh with river fishing, kayaking, hiking, and wildlife-watching. The park contains the northernmost freshwater tidal marsh on the Delaware River, Abbott Marshland. Since the mid-1990s, many public and private partnerships have developed to help support the preservation of this important and significant marsh.
Our Field Operations Team was recently at the project site assessing present invasive species and re-evaluating access points for our treatment equipment. Check out these photos from their visit!
For more information on this marsh restoration project at John A. Roebling Park, visit our original project blog:
Wreck Pond is a tidal pond located on the coast of the Atlantic Ocean in southern Monmouth County, New Jersey. The 73-acre pond, which was originally connected to the sea by a small and shifting inlet, got its name in the 1800s due to the numerous shipwrecks that occurred at the mouth of the inlet. The Sea Girt Lighthouse was built to prevent such accidents. In the 1930s, the inlet was filled in and an outfall pipe was installed, thus creating Wreck Pond. The outfall pipe allowed limited tidal exchange between Wreck Pond and the Atlantic Ocean.
In the 1960s, Wreck Pond flourished with wildlife and was a popular destination for recreational activities with tourists coming to the area mainly from New York City and western New Jersey. In the early spring, hundreds of river herring would migrate into Wreck Pond, travelling up its tributaries — Wreck Pond Brook, Hurleys Pond Brook and Hannabrand Brook — to spawn. During the summer, the pond was bustling with recreational activities like swimming, fishing, and sailing.
Over time, however, the combination of restricted tidal flow and pollution, attributable to increased development of the watershed, led to a number of environmental issues within the watershed, including impaired water quality, reduced fish populations, and flooding.
Throughout the Wreck Pond watershed, high stream velocities during flood conditions have caused the destabilization and erosion of stream banks, which has resulted in the loss of riparian vegetation and filling of wetlands. Discharge from Wreck Pond during heavy rains conveys nonpoint source pollutants that negatively impact nearby Spring Lake and Sea Girt beaches resulting in beach closings due to elevated bacteria counts. Watershed erosion and sediment transported with stormwater runoff has also contributed to excessive amounts of sedimentation and accumulations of settled sediment, not only within Wreck Pond, but at the outfall pipe as well. This sediment further impeded tidal flushing and the passage of anadromous fish into and out of Wreck Pond.
In 2012, Hurricane Sandy caused wide-spread destruction throughout New Jersey and the entire eastern seaboard. The storm event also caused a major breach of the Wreck Pond watershed’s dune beach system and failure of the outfall pipe. The breach formed a natural inlet next to the outfall pipe, recreating the connection to the Atlantic Ocean that once existed. This was the first time the inlet had been open since the 1930s, and the reopening cast a new light on the benefits of additional flow between the pond and the ocean.
Hurricane Sandy sparked a renewed interest in reducing flooding impacts throughout the watershed, including efforts to restore the water quality and ecology of Wreck Pond. The breach caused by Hurricane Sandy was not stable, and the inlet began to rapidly close due to the deposition of beach sand and the discharge of sediment from Wreck Pond and its watershed.
Princeton Hydro and HDR generated the data used to support the goals of the feasibility study through a USACE-approved model of Wreck Pond that examined the dynamics of Wreck Pond along with the water bodies directly upland, the watershed, and the offshore waters in the immediate vicinity of the ocean outfall. The model was calibrated and verified using available “normalized” tide data. Neighboring Deal Lake, which is also tidally connected to the ocean by a similar outfall pipe, was used as the "reference" waterbody. The Wreck Pond System model evaluated the hydraulic characteristics of Wreck Pond with and without the modified outfall pipe, computed pollutant inputs from the surrounding watershed, and predicted Wreck Pond's water quality and ecological response. The calibrated model was also used to investigate the effects and longevity of dredging and other waterway feature modifications.
As part of the study, Princeton Hydro and HDR completed hazardous, toxic, and radioactive waste (HTRW) and geotechnical investigations of Wreck Pond's sediment to assess potential flood damage reduction and ecological restoration efforts of the waterbody. The investigation included the progression of 10 sediment borings conducted within the main body of Wreck Pond, as well as primary tributaries to the pond. The borings, conducted under the supervision of our geotechnical staff, were progressed through the surgical accumulated sediment, not the underlying parent material. Samples were collected for analysis by Princeton Hydro’s AMRL-accredited (AASHTO Materials Reference Library) and USACE-certified laboratory. In accordance with NJDEP requirements, sediment samples were also forwarded to a subcontracted analytical laboratory for analysis of potential nonpoint source pollutants.
In the geotechnical laboratory, the samples were subjected to geotechnical indexing tests, including grain size, organic content, moisture content, and plasticity/liquid limits. For soil strength parameters, the in-field Standard Penetration Test (SPT), as well as laboratory unconfined compression tests, were performed on a clay sample to provide parameters for slope stability modeling.
The culvert construction and sediment dredging were completed at the end of 2016. Continued restoration efforts, informed and directed by the data developed through Princeton Hydro's feasibility study, are helping to reduce the risk of flooding to surrounding Wreck Pond communities, increase connectivity between the pond and ocean, and improve water quality. The overall result is a healthier, more diverse, and more resilient Wreck Pond ecosystem.
To learn more about our geotechnical engineering services, click here.
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Along the Third River and Spring Brook, two freshwater tributaries of the Passaic River, a disturbed industrial site is being transformed into 4.2 acres of wetlands, restoring the natural floodplain connection, enhancing aquatic habitat, and increasing flood storage capacity for urban stormwater runoff. The groundbreaking ceremony for this important ecological restoration project for Bloomfield Township took place last month.
"The Third River Floodplain Wetland Enhancement Project is a unique, creative solution that will transform a highly-disturbed, flood-prone, former industrial site into a thriving public park allowing for both passive and active recreational activities,” said Mark Gallagher, Vice President of Princeton Hydro. “By removing a little over four acres of upland historic fill in this densely developed area and converting it to a functioning floodplain wetland, the project will restore valuable ecological functions, increase flood storage capacity, and enhance wildlife habitat."
Princeton Hydro is serving as the ecological engineer to Bloomfield Township for the Third River Floodplain Wetland Enhancement Project. Princeton Hydro’s scientists and engineers have assisted in obtaining grants, collected background ecological data through field sampling and surveying, created a water budget, completed all necessary permitting, and designed both the conceptual and final restoration plans. Additionally, Princeton Hydro will be conducting construction oversight during the implementation of this important urban wetland creation project.
The site includes 1,360 feet along the east bank of the Third River and 3,040 feet along the banks of the Spring Brook. These waterways are freshwater tributaries of the Passaic River and share a history of flooding above the site’s 100-year flood plain. The Third River, like many urban streams, tends to be the victim of excessive volume and is subjected to erosion and chronic, uncontrolled flooding. This green infrastructure project will re-establish the natural floodplain wetland and riparian plant communities, which will lead to a species-rich forest community through the removal of invasive species, setting the stage for native plants.
“Over 500 trees and shrubs will be planted in the new wetland with additional trees and shrubs being planted along Lion Gate Drive and in existing woodlands. The selected native plant species all provide important wildlife value such as providing fruit for migratory birds,” Gallagher explained. “We are excited to work with Bloomfield Township to design an urban restoration project that will both enhance the site’s ecological and flood storage value and provide accessibility to the community of Bloomfield.”
It is estimated that Phase One of the project, which includes the wetland construction and plantings, will be completed by September 1, 2019. The maintenance building, concession stand, ball field, etc., will be constructed as part of Phase Two.
“We are very excited to break ground on this exciting project that will have tremendous public benefits, like providing much-needed open space and lowering flood insurance rates for nearby residents and businesses,” said Bloomfield Township Mayor Michael Venezia. “By taking an underutilized parcel of land and turning it into beautiful park and waterfront space to be enjoyed by the public, we are fulfilling our commitment to preserving and enhancing open space. We would not have accomplished this without the efforts of Councilman Nick Joanow, who has advocated for this park for many years, Township Administrator Matthew Watkins, our excellent contractors and environmental experts, and I would like to thank them all. I also want to thank the Department of Environmental Protection and Freshwater Wetlands Mitigation Council for their important grant assistance to help us jump start this complex which will enrich the lives of Bloomfield residents for decades to come.”
NY/NJ Baykeeper has been vital in bringing the project to fruition, having served as an advocate for the project for the last 17 years.
"Lion's Gate natural restoration is a legitimate all-in-one project that uses green infrastructure and smart planning to address the nested set of urban land use challenges, including: stormwater management, flooding, brownfield cleanup, natural habitat restoration, and the need for both more active playing fields and more passive greenfields," said Greg Remaud, Baykeeper and CEO, NY/NJ Baykeeper.
Together, Bloomfield Township, Strauss and Associates, ARH, and Princeton Hydro secured $1.76 million in funding for this project from the New Jersey Freshwater Wetlands Mitigation Council and another several million dollars from NJDEP’s Office of Natural Resource Restoration.
The Pin Oak Forest Conservation Area, located in a heavily developed area of northern Middlesex County, New Jersey, once suffered from wetland and stream channel degradation, habitat fragmentation, decreased biodiversity due to invasive species, and ecological impairment. The site was viewed as one of only a few large-scale freshwater wetland restoration opportunities remaining in this region of New Jersey. Thus, a dynamic partnership between government agencies, NGOs, and private industry, was formed to steward the property back to life and restore its natural function. Today, at Bowman’s Hill Wildflower Preserve's 19th Annual Land Ethics Symposium, Middlesex County and the project team were presented with the "Land Ethics Award of Merit" for its remarkable restoration achievements.
“In just a few years, the landscape at Pin Oak has transformed from a degraded, disconnected wetland to a healthy, high-functioning landscape,” said Mark Gallagher, Vice President of Princeton Hydro. “This restoration project exemplifies how a diverse group of public and private entities can work together to identify opportunities, overcome challenges and achieve tremendous success.”
The Pin Oak restoration team includes Middlesex County Office of Parks and Recreation, Woodbridge Township, Woodbridge River Watch, New Jersey Freshwater Wetlands Mitigation Council, GreenTrust Alliance, GreenVest, and Princeton Hydro.
The Pin Oak Forest Conservation Area is a 97-acre tract of open space that contains a large wetland complex at the headwaters of Woodbridge Creek. In 2017, the award-winning restoration project converted over 30 acres of degraded freshwater wetlands, streams and disturbed uplands dominated by invasive species into a species-rich and highly functional headwater wetland complex. The resulting ecosystem provides valuable habitat for wildlife and a nurturing environment for native plants such as pin oak, swamp white oak, marsh hibiscus, and swamp rose. The restored headwater wetland system provides stormwater management, floodplain storage, enhanced groundwater recharge onsite, and surface water flows to Woodbridge Creek, as well as public hiking trails, all benefiting the town of Woodbridge.
The Land Ethics Award recognizes the creative use of native plants in the landscape, sustainable and regenerative design, and ethical land management and construction practices. The recipient is selected by a jury of professionals in the field of design, preservation and conservation, and the award is presented at the Annual Symposium.
Established in 1934, Bowman’s Hill Wildflower Preserve is a 134-acre nature preserve, botanical garden, and accredited museum working to inspire the appreciation and use of native plants by serving as a sanctuary and educational resource for conservation and stewardship. For more information, visit www.bhwp.org.
Tidal marshes, like the 3,000-acre Abbott Marshlands, contain valuable habitat for many rare species like River Otter, American eel, Bald Eagle, and many species of wading birds. Unfortunately, the Abbott Marshland has experienced a significant amount of loss and degradation, partially due to the introduction of the invasive Phragmites australis, or, Common Reed.
Phragmites australis is a species of grass that has a non-native invasive form that creates extensive strands in shallow water or on damp ground. The reed tends to colonize disturbed wetlands and then spreads very rapidly, outcompeting desirable native plant species. Once it is established, it forms a monoculture with a dense mat and does not allow any opportunity for native plants to compete. This impairs the natural functioning of the marsh ecosystem by altering its elevations and tidal reach which impacts plant and animal communities. Over the last century, there has been a dramatic increase in the spread of Phragmites australis, partly due to development impacts that resulted in disturbances to wetlands.
For the Mercer County, Princeton Hydro put together a plan to reduce and control the Phragmites australis, in order to increase biodiversity, to improve recreational opportunities, and to improve visitor experience at the park. This stewardship project will replace the Phragmites australis with native species with a goal to reduce its ability to recolonize the marsh. In September, our Vice President Mark Gallagher and Senior Project Manager Kelly Klein presented our plan to the public at the Tulpehaking Nature Center.
Princeton Hydro conducted a Floristic Quality Assessment to identify invasive areas and performed hydrologic monitoring to understand tidal stage elevations. Phase 1 of the restoration process occurred this fall and included herbicide applications to eradicate the Phragmites australis. The herbicide used, Imazapyr, is USEPA and NJDEP approved and our field operation crew applied it using our amphibious vehicle called a Marsh Master. For harder to reach areas, we used our airboat.
According to a USDA report, Imazapyr has been extensively studied, and when properly applied, it has no impact to water quality, aquatic animal life, birds, or mammals, including humans. It works by preventing plants from producing a necessary enzyme called acetolactate synthase.
The goal of this wetland restoration project is to enhance plant diversity, wildlife habitat, and water quality in John A. Roebling Memorial Park. In late spring of 2019, we will revisit the site to continue spraying the Phragmites australis. By Spring of 2020, we expect to see native species dominating the landscape from the newly exposed native seed bank with minimal Phragmites australis. Stay tuned for more photos from the field when our Field Crew returns to the site for Phase II in early Spring!
In this two part blog series, we showcase our work in the Moodna Creek Watershed in order to explore some of the concepts and methods used to estimate flood risk for existing conditions and the year 2050 and develop a flood management strategy (Part One), and traditional engineering and natural systems solutions used to manage and reduce flood risk (Part Two).
The greater Moodna Creek watershed covers 180 square miles of eastern Orange County, NY. The watershed includes 22 municipalities and hundreds of streams before joining the Hudson River. This region has seen tremendous growth in recent years with the expansion of regional transit networks and critical infrastructure.
The Moodna Creek watershed can be split into two sub-basins — the Upper Moodna Creek and the Lower Moodna Creek. In the span of 15 months, Hurricane Irene, Tropical Storm Lee, and Hurricane Sandy each have caused significant flooding throughout the Moodna Creek watershed, damaging public facilities, roadways, and private properties. Both sub-basin communities have noted a concern about increased flood risk as more development occurs.
As global temperatures rise, climate models are predicting more intense rainfall events. And, the flood risk for communities along waterways — like the Moodna Creek watershed — will likely increase as time passes. In order to understand existing and future risk from flood events in this flood-prone area, a flood risk management strategy needed to be developed. The strategy uses a cost-benefit analysis to review the feasibility of each measure and the overall impact in reducing flood risks.
With funds provided from a 2016 grant program sponsored by the New England Interstate Waters Pollution Control Commission (NEIWPCC) and the New York State Department of Environmental Conservation's (NYCDEC) Hudson River Estuary Program (HEP), Princeton Hydro along with a variety of project partners completed a flood assessment and flood mitigation analysis specific to the Lower Moodna Creek watershed.
Let’s take a closer look at our work with the Lower Moodna Creek watershed, and explore some of the methods used to estimate flood risk and develop a flood management strategy:
The primary Lower Moodna Creek project goals were to assess flood vulnerabilities and propose flood mitigation solutions that consider both traditional engineering strategies and natural systems solution approaches (land preservation, wetland/forest restoration, green infrastructure and green water management). The project team focused on ways to use the natural environment to reduce risk. Instead of strictly focusing on just Moonda Creek, the team took a holistic approach which included all areas that drain into the river too. These analyses were incorporated into a Flood Assessment Master Plan and Flood Mitigation Plan, which will serve as a road map to reducing flooding issues within the watershed.
The first step in managing flood risk is to understand what type of exposure the communities face. The Moodna Creek project modeled flooding within the watershed during normal rain events, extreme rain events, and future rain events with two primary goals in mind:
The project team used these models and data to propose and evaluate a series of design measures that help reduce and mitigate existing and anticipated flood risk within the study area. Where possible, the proposed solutions prioritized approaches that protect and/or mirror natural flood protection mechanisms within the watershed such as floodplain re-connection and wetland establishment. In addition to flood protection, the project components also provide water quality protection, aesthetics and recreation, pollutant reduction, and wildlife habitat creation.
Zoning is a powerful tool that determines a region’s exposure to hazards and risk. Zoning determines which uses are permitted, or encouraged, to be built in moderate and high-risk areas. It also prevents certain uses, such as critical facilities, from being built in those areas. Zoning is also a determinant of a region’s character and identity.
In the Lower Moodna Creek watershed, a large majority (82%) of land is zoned for residential use. However, in the flood-prone areas, there is a higher ratio of areas zoned for non-residential uses (commercial, industrial) than in areas that are zoned for potential future development. Specifically, within the 10-year storm recurrence floodplain, 30% of the land is zoned for industrial use. This is likely because several facilities, such as wastewater treatment plants and mills, require access to the river and were strategically developed to be within immediate proximity of waterfront access. The Lower Moodna zoning analysis demonstrated a general preference within watershed to limit residential use of flood-prone areas.
Preserving land allows for natural stormwater management, as well as limits the exposure of development, and minimizes sources of erosion within the watershed. Preserved land also maintains the hydrologic and ecologic function of the land by allowing rainwater to be absorbed or retained where it falls and thus minimizing run-off. If the land within the floodplain is preserved, it will never be developed, and therefore the risk — a calculation of rate exposure and the value of the potential damage — is eliminated. Therefore, land preservation, both within the floodplains and in upland areas, is the best way to minimize flood damage.
Conserved riparian areas also generate a range of ecosystem services, in addition to the hazard mitigation benefits they provide. Protected forests, grasslands, and wetlands along rivers and streams can improve water quality, provide habitat to many species, and offer a wide range of recreational opportunities. Given the co-benefits that protected lands provide, there is growing interest in floodplain conservation as a flood damage reduction strategy.
Within the mapped Lower Moodna floodplains, our assessment determined that there appears to be a slight priority for preserving land most at-risk for flooding. This is likely a consequence of prioritizing land that is closest to riparian areas and preserving wetland areas, which are the most likely to experience flooding. Within the floodplains for the 10-year storm, approximately 22.7% is preserved. For the 100-year storm, approximately 21.2% of the land is preserved. Within the 500-year storm, this number drops slightly to 20.3%. These numbers are so close in part because the difference between the 10-year, 100-year, and 500-year floodplains are small in many areas of the watershed.
Hydrology is the scientific study of the waters of the earth, with a particular focus on how rainfall and evaporation affect the flow of water in streams and storm drains. Hydraulics is the engineering analysis of the flow of water in channels, pipelines, and other hydraulic structures. Hydrology and hydraulics analyses are a key part of flood management.
As part of this flood assessment, Princeton Hydro created a series of hydrologic and hydraulic (H&H) models to assess the extent of potential flooding from the 10-year, 100-year, and 500-year storm recurrence intervals within the Lower Moodna. The modeling, which included flows for these storm events under existing conditions and future conditions based on predicted increases in precipitation and population growth, makes it easier to assess what new areas are most impacted in the future.
These are just a few of the assessments we conducted to analyze the ways in which flooding within the watershed may be affected by changes in land use, precipitation, and mitigation efforts. The flood models we developed informed our recommendations and proposed flood mitigation solutions for reducing and mitigating existing and anticipated flood risk.
Check out Part Two of this blog series in which we explore flood risk-reduction strategies that include both traditional engineering and natural systems solutions:
For more information about Princeton Hydro's flood management services, go here.
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