Study Data Leads to Healthier Wreck Pond Ecosystem

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.

During the time of the progression of study by the USACE, the American Littoral Society and the towns of Spring Lake and Sea Girt were also progressing their own restoration effort and completed the implementation of an additional culvert to the Atlantic Ocean.  The American Littoral Society was able to utilize the data, analysis, and modeling results developed by the USACE to ensure the additional culvert would increase tidal flushing and look to future restoration projects within Wreck Pond.

American Littoral Society

 

To learn more about our geotechnical engineering services, click here.

Urban Wetland Restoration to Yield Flood Protection for Bloomfield Residents

As part of the Third River Floodplain Wetland Enhancement Project,
a disturbed, flood-prone industrial site will be converted into a thriving public park.

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.

To read more about our wetland restoration work, go here: http://bit.ly/PHwetland

 

Wetland Restoration Project Wins “Land Ethics” Award of Merit

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.

Photo courtesy of Barbara Storms, Bowman’s Hill Wildflower Preserve.

In addition to the Award of Merit, Bowman’s Hill Wildflower Preserve’s honored Dr. Marion Kyde with the 2019 Land Ethics Director’s Award and Doylestown Township Environmental Advisory Council with the 2019 Land Ethics Award. Congratulations to all of the winners!

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.

Read more about the Pin Oak Forest Restoration project:

Innovative and Effective Approach to Wetland Restoration

To learn more about Princeton Hydro’s wetland restoration services and recent projects, visit us here: http://bit.ly/PHwetland

 

Conservation Spotlight: Reducing Flood Risk and Restoring Wetlands in Jamaica Bay

Located in Queens, New York on the northern shore of Jamaica Bay, Spring Creek South contains approximately 237 acres of undeveloped land, including wetlands and 2.4 miles of coastline. The site is bounded by the Howard Beach residential neighborhood in Queens, a commercial area along Cross Bay Boulevard, the Belt Parkway, and Jamaica Bay. The northwest section of Spring Creek South is part of the National Park Service’s Gateway National Recreation Area, and is largely comprised of small patches of degraded tidal marsh and disturbed and degraded upland ecosystems.

On October 29, 2012, Hurricane Sandy drove a catastrophic storm surge into the New Jersey and New York coastlines. Spring Creek South and the surrounding community of Howard Beach experienced record flooding and damage to property and critical infrastructure. Storm tides caused damage and erosion along the shoreline and in the salt marsh area, degrading important habitat and leaving the site vulnerable to invasive species.

Hurricane Sandy Aftermath at Howard Beach, taken 10/30/2012 by Pam Andrade

The New York State Division of Homeland Security and Emergency Services (NYSDHSES) was awarded funding from FEMA’s Hazard Mitigation Grant Program to restore Spring Creek South. The U.S. Army Corps of Engineers (USACE) New York District, serving as project administrator, contracted Princeton Hydro to provide ecosystem restoration services. The goal of the project is to reduce future flood risk exposure while also protecting, restoring, and improving the quality and function of ecological systems; improving stormwater management and water quality; and enhancing the park’s visitor experience.

To achieve this goal, the project team is using an integrated approach that involves utilizing green infrastructure to create a natural barrier for the community and reduce the risks of coastal storms. Project activities include berm construction and the restoration of tidal marsh, creation of freshwater wetland forest, and creation of maritime shrub, forest, and grassland habitats, as well as stabilization of the existing shoreline.

On December 31, 2018, we completed Phase One of the project, which entails engineering design and preliminary permitting. More specifically, we’ve provided conceptual planning; analysis of subsurface soils for geotechnical properties and hazardous waste; coastal and freshwater wetland delineations; biological benchmarking analysis; and the development of sea level rise curves and two-dimensional hydrologic and hydraulic coastal modeling. As part of the hydrology study, we analyzed what the site could be expected to look like in 50 years due to climate changes and sea level rise. Our engineering design was also brought to 65% completion.

We also obtained permits, prepared the Environmental Assessment (EA), and oversaw the National Environmental Policy Act (NEPA) process. The EA received a “Finding of No Significant Impact” (FONSI) from FEMA, which means the environmental analysis and interagency review concluded that the project has no significant impacts on the quality of the environment.

Due to the complex nature of this project and its location, we are coordinating with a variety of different entities, including the local Howard Beach Community Board, the FAA (proximity to JFK International Airport), Port Authority, USACE, NOAA Fisheries, USFWS, USEPA, NYSDEC, NYC DEP, the National Park Service, HDR Engineering and WSP Engineering.

Phase Two of the project is the construction phase, which is expected to take about two years to complete. A key part of the Spring Creek South construction activities is the restoration of approximately 40 acres of tidal marsh, which is anticipated to improve water quality locally by stabilizing sediment, reducing erosion, and filtering dissolved particulate materials. The project team will restore existing coastline areas and install a salt marsh along the shoreline. Planted with native flora, like Spartina alterniflora, a perennial deciduous grass found in intertidal wetlands, the coastal salt marsh will help to stabilize sediment. Additionally, removing invasive species like Phragmites australis from the area and replacing it with native plant species will increase the ability for native vegetation to colonize the site, improve vegetative diversity, and reduce fire risk in the park.

A forested wetland area and berm will also be created in order to provide the surrounding communities with natural shields and buffers to future storms. The berm, with an elevation of 19 feet (NAVD88), will help to manage the risk of storm surge flooding caused by coastal storms. The forested wetland area will also provide improved stormwater runoff storage, naturally filter stormwater, and, via flap gates, direct its flow toward Jamaica Bay, away from residential and commercial properties.

These measures will help to dissipate wind and wave energy, increase shoreline resilience, improve stormwater management at the site, and create habitat that increases the ecological value and biodiversity at the site, while providing resilience benefits. Restoration activities will benefit vulnerable and rare ecological communities by producing localized environmental enhancements, including improving water quality and creating and restoring habitat. The project also increases opportunities for recreational uses such as wildlife viewing/photography, fishing, and nature study.

Princeton Hydro specializes in the planning, design, permitting, implementing, and maintenance of wetland rehabilitation projects. To learn more about some of our ecosystem restoration and enhancement services, visit: bit.ly/PHwetland.

 

Restoring the Northernmost Freshwater Tidal Marsh on the Delaware River

By Kelsey Mattison, Marketing Coordinator

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.

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

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.

Vice President Mark Gallagher presenting on the project 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!   

View of John A. Roebling Memorial Park from the access road.

For more information about Princeton Hydro’s invasive species removal and wetland restoration services, visit: bit.ly/InvasivesRemoval 

Kelsey Mattison is a recent graduate of St. Lawrence University with a degree in English and environmental studies and a passion for environmental communication. Through her extracurricular work with various nonprofit organizations, Kelsey has developed expertise in content writing, storytelling, verbal communication, social media management, and interdisciplinary thinking. Her responsibilities at Princeton Hydro include social media management, proposal coordination, editorial overview, and other marketing tasks. As a member of the Princeton Hydro team, she aims to further its mission by taking creative approaches to communicating about our shared home: Planet Earth.

Two-Part Blog Series: Flood Assessment, Mitigation & Management

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).

Part One: Flood Assessment & Mitigation Analysis in the Moodna Creek Watershed

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:

Lower Moodna Creek Watershed Flood Assessment & Analysis

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.

Managing Flood Risk

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:

Visual assessment being conducted in flood-prone areas of Moodna Creek Watershed.

  • Assess the facilities, infrastructure, and urban development that are at risk from flooding along the Moodna Creek and its tributaries within the study area.
  • Develop a series of hydrologic and hydraulic models to assess the extent of potential flooding from the 10-year (10%), 100-year (1%),  and 500-year (0.2%) storm recurrence intervals within the study area. The modeling includes flows for these storm events under existing conditions and also hypothetical scenarios with predicted increases in precipitation and population growth.

 

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.

Land Use and Zoning

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. 

Land Preservation

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 and Hydraulics

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:

Part Two: Reducing Flood Risk in Moodna Creek Watershed

For more information about Princeton Hydro’s flood management services, go here: http://bit.ly/PHfloodplain.

 

Mitigation Milestone Reached at Mattawoman Creek Mitigation Site

Photo courtesy of GreenVest

Mattawoman Creek Mitigation Project will Restore and Protect 80+ Acres of Mattawoman Creek, Chesapeake Bay’s Most Productive Tributary

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.

Pictured is the southern restoration area after
sorghum germination, prior to wetland creation
and reestablishment.
A function-based stream assessment was
performed on the degraded channel.

 

Photo courtesy of GreenVestDesign, 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.

Highlights from the Mattawoman Creek Wetland and Stream Mitigation project:
  • 80 acres of land were placed into conservation easement and removed from active row crop production and cattle pasture. The easement, which is held by GreenTrust Alliance, provides permanent protection for all 80 acres.
  • Over 64 acres of wetlands will be restored, created, enhanced or preserved, which will sequester approximately 75 tons of carbon per year.
  • 3,798 linear feet of perennial stream will be restored by re-establishing, historic floodplain access during more frequent storm events, stabilizing hydraulics and geomorphology, and adding aquatic habitat value.
  • Full integration of the wetland and stream restoration elements will occur exponentially, increasing anticipated functions and values in the post construction condition. Functions include: storm damage and flood attenuation, groundwater recharge and discharge, nutrient cycling and sequestration, local water quality improvement, and wildlife habitat enhancements.
  • This project will also create and enhance the forested wetland and stream habitat for the State-listed Threatened Selys’ Sundragon (Helocordulia selysii).
  • As part of the site design, over 28,500 native trees and shrubs will be planted.
  • The Mattawoman Creek Mitigation Site is located within a Tier 3 Biodiversity Conservation Network area. These areas are classified by the Department of Natural Resources as “highly significant for biodiversity conservation” and are priority conservation areas that support critical species and habitats.
  • The project will yield advanced mitigation values: 7.913 in wetland credits and 1,595 in stream credits. These credits are durable and will be available for JBA’s use in order to satisfy permitted impacts associated with planned capital improvement projects.

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

Pin Oak Forest Restoration Project Wins Award for “Excellence in Water Resources Management”

A unique group of partners collaborated to successfully restore wetlands and streams in Woodbridge, New Jersey, garnering a prestigious award from the NJ-AWRA.

Degraded freshwater wetlands, uplands, and channelized streams have been transformed into thriving habitat teeming with wildlife at the Pin Oak Forest Conservation Area in Woodbridge, New Jersey. A dynamic partnership between government agencies, NGOs, and private industry, was formed to restore the natural function and steward the property back to life. On September 28, the New Jersey Section – American Water Resources Association (NJ-AWRA) presented the project team with the “Excellence in Water Resources Management” Award at their 14th Annual Water New Year’s Eve Celebration.

“The AWRA is an organization with a solid vision around comprehensive water resource management – a vision that more agencies should be emulating,” said Kirk Mantay, Director of Operations at GreenTrust Alliance. “We are grateful to be recognized for having achieved this vision at Pin Oak Forest, and are excited to see our model replicated in more water resource projects throughout New Jersey.”

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. The site hosts a network of trails that are accessible to the community and are actively used by residents for recreation. Recognizing the need to provide high-quality habitat on public lands that are preserved indefinitely, partners designed a restoration project to benefit both wildlife and the community.

In 2017, the 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 including the state-threatened Black-crowned Night-heron and Red-headed Woodpecker. Biodiversity was also increased through invasive species management, which allowed establishment of 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.

Photo courtesy of Mark Gallagher.

Public and private partnerships were and continue to be critical to the success of this project. The diverse partnership 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.

“It is amazing to witness the transformation of a degraded, disconnected wetland to a healthy, high-functioning landscape in just a few years,” said Mark Gallagher, Vice President of Princeton Hydro. “The Pin Oak Forest restoration project is an excellent model for showcasing a successful approach to the enhancement of public lands through a dynamic multidisciplinary, multi-stakeholder partnership.”

AWRA’s Excellence in Water Resources Management Award highlights water infrastructure projects that demonstrate an innovative and effective approach to water resources management. Projects must leverage unique partnerships among multiple stakeholders, ideally including public/private partnerships. The projects must also embody the mission of the AWRA to advance multidisciplinary water resources education, management and research. The Pin Oak Forest Project excelled in these areas, resulting in the successful nomination of the project to receive the award.

Read more about the Pin Oak Forest Restoration project:

Innovative and Effective Approach to Wetland Restoration

To learn more about Princeton Hydro’s wetland restoration services and recent projects, visit us here: http://bit.ly/PHwetland

 

Innovative and Effective Approach to Wetland Restoration

The Pin Oak Forest Conservation Area is a 97-acre tract of open space that contains an extremely valuable wetland complex at the headwaters of Woodbridge Creek. The site is located in a heavily developed landscape of northern Middlesex County and is surrounded by industrial, commercial, and residential development. As such, the area 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 highly developed region of New Jersey.

Recognizing the unique qualities and great potential for rehabilitating and enhancing ecological function on this county-owned parkland, a dynamic partnership between government agencies, NGOs, and private industry, was formed to restore the natural function of the wetlands complex, transform the Pin Oak Forest site into thriving habitat teeming with wildlife, and steward this property back to life. The team designed a restoration plan that converted 28.94 acres of degraded freshwater wetlands, 0.33 acres of disturbed uplands dominated by invasive species, and 1,018 linear feet of degraded or channelized streams into a species-rich and highly functional headwater wetland complex.

BEFORE
View of stream restoration area upon commencement of excavation activities. View of containerized plant material staged prior to installation.

 

We used an innovative approach to restore the hydraulic connection of the stream channel with its floodplain in order to support wetland enhancement. Additionally, to further enhance wetlands with hydrologic uplift, the team incorporated microtopography techniques, which creates a variable surface that increases groundwater infiltration and niches that support multiple habitat communities. This resulted in a spectrum of wetland and stream habitats, including the establishment of a functional system of floodplain forest, scrub shrub, emergent wetlands and open water. Biodiversity was also increased through invasive species management, which opened the door for establishing key native flora such as red maple, pin oak, swamp white oak, and swamp rose. The restored headwater wetland system also provides stormwater quality management, floodplain storage, enhanced groundwater recharge onsite, and surface water flows to Woodbridge Creek.

Completed in 2017, the integrated complex of various wetland and upland communities continues to provide high quality habitat for a wide variety of wildlife species including the state-threatened Black-crowned Night heron and Red-headed Woodpecker. The work done at the site significantly enhanced ecological function, providing high-quality habitat on indefinitely-preserved public lands that offer countless benefits to both wildlife and the community.

AFTER
Post-restoration in 2018, looking Northeast. View of wetland enhancement approximately 2 months after completion of seeding and planting activities.

 

Public and private partnerships were and continue to be critical to the success of this project. The diverse partnership 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 partners joined together as stakeholders to identify long term restoration and stewardship goals for Pin Oak Forest Preserve, and nearly four years later, the partners all remain involved in various aspects of managing the property and this project itself, ranging from fiscal oversight by New Jersey Freshwater Wetland Mitigation Council and GreenTrust Alliance, to permit and landowner access coordination performed by Woodbridge Township and Middlesex County, or the ongoing stewardship, maintenance, and monitoring of the project and the larger park, being conducted by being conducted by GreenTrust Alliance, GreenVest, and NJ Department of Environmental Protection.

This project was funded through the New Jersey Freshwater Wetland In-Lieu Fee program. In 2014, GreenTrust Alliance, GreenVest, and Princeton Hydro secured $3.8 million dollars of funding on behalf of the Middlesex County Parks Department to restore three wetland sites, which included Pin Oak Forest.

The Pin Oak Forest project is a great model for showcasing a successful approach to the enhancement of public lands through a dynamic multidisciplinary, multi-stakeholder partnership. And, because of proper planning and design, it has become a thriving wildlife oasis tucked in the middle of a densely-populated suburban landscape.

Princeton Hydro specializes in the planning, design, permitting, implementing, and maintenance of wetland rehabilitation projects. To learn more about our wetland restoration, creation, and enhancement services, visit: bit.ly/PHwetland

Teaching NYC High Schoolers About Wetlands

Ms. Hannah Goldstein and her Environmental Science students at Franklin Delano Roosevelt High School in Brooklyn, NY welcomed Emily Bjorhus, Princeton Hydro Environmental Scientist, to be a guest speaker on the topic of wetlands. The students, 10th, 11th, and 12th graders, learned what defines a wetland, how wetlands function, and why wetland ecosystems are important to our communities. Emily also taught the students how to identify wetlands in the field.

The presentation also involved hands-on instruction, which included a trip outside to the school courtyard where students learned how to collect soil samples using an auger and how to determine if hydric soils are present. To identify surrounding trees, students used a dichotomous key, a tool that allows users to make a series of choices based on characteristics such as leaf and fruit shape. Using the skills and information they learned, Emily helped each classroom determine whether a wetland was present. As it turns out, the courtyard in the middle of Franklin Delano Roosevelt High School does not contain a wetland!

“Science is such an important subject matter for kids to be learning for a variety of reasons. Environmental science education in particular encourages thought patterns, which get kids engaged in real-world environmental protection activities,”  said Emily. “I really enjoyed working with Ms. Goldstein and her students. I hope my presentation inspires the students to learn more about wetlands and become ambassadors of wetland conservation.”

To learn more about Princeton Hydro’s tidal and freshwater wetland services, visit: bit.ly/PHwetland