Protecting Greenwood Lake’s Water Quality Through Stormwater Management

The summer is upon us and Lakes Appreciation Month is right around the corner, what better time to pay a visit to and learn more about the lakes in your area.

Princeton Hydro conducts work on lakes throughout the Northeast to preserve, protect and improve water quality and ecological health, ensuring that your community lakes can be enjoyed now and into the future. Today, we’re putting the spotlight on Greenwood Lake:

Greenwood Lake, a 7-mile-long interstate lake that straddles the border of New York and New Jersey, is a popular recreation spot for residents and tourists of both states. Considered to be one of the top bass fishing lakes in New Jersey, Greenwood Lake is abundant with largemouth and smallmouth bass, yellow perch, chain pickerel and catfish. The lake is also extensively used by residents for swimming and boating.

For over 35 years, Princeton Hydro’s scientists have worked with New Jersey, local governing municipalities, and the various environmental organizations involved with the protection of Greenwood Lake and its watershed. In the early 2000s, we developed a comprehensive Restoration Plan and a proactive monitoring program that we have used over the years to properly manage the lake and its watershed. The plan was developed for the Greenwood Lake Commission and the Township of West Milford with funding provided through the New Jersey Department of Environmental Protection’s Nonpoint Source 319(h) Program. The Restoration Plan focuses heavily on the implementation of various types of stormwater best management practices (BMPs) to help reduce the influx of sediment and nutrients into the lake. We track the positive effects and benefits achieved through these stormwater projects by conducting both storm-event based and in-lake water quality monitoring.

The goal of the stormwater-based efforts is to ensure the lake’s total phosphorus (TP) load is systematically reduced in accordance with the lake’s established Total Maximum Daily Load (TMDL). The TMDL is a regulatory term in the U.S. Clean Water Act, that identifies the maximum amount of a pollutant (in this case phosphorus) that a waterbody can receive while still meeting water quality standards. Princeton Hydro was instrumental in developing the TMDL for Greenwood Lake. Phosphorus entering the lake from runoff is the primary driver of the lake’s eutrophication. The direct results of eutrophication are increases in the density of aquatic plants and nuisance algae. All this added productivity leads to reduced clarity, reductions in dissolved oxygen concentrations, and a number of other ecological impacts that compromise the quality, aesthetics, and use of the lake.

Last year, Princeton Hydro and the Greenwood Lake Commission, with input from the West Milford Environmental Commission, proposed an updated Watershed Implementation Plan (WIP) for the lake. Approved and funded by the NJ Highlands Council, the updated WIP includes a variety of components that build upon the original Restoration Plan and incorporate newly advanced stormwater management and Nonpoint Source Pollution (NPS) reduction technologies.

Belcher's Creek at Edgecumb and Glencross

The WIP includes in‐lake and stream monitoring; the assessment of the existing stormwater structures installed through grant‐based, watershed activities; and the identification of watershed-based projects that can be completed to support the Lake’s compliance with TMDL TP levels with a specific focus on the stormwater runoff produced by Belcher’s Creek, a major tributary to Greenwood Lake.

The WIP also includes the following nine minimum elements considered necessary by both NJDEP and USEPA for funding eligibility:

  1. Identify causes and sources of pollution
  2. Estimate pollutant loading into the watershed and the expected load reductions
  3. Describe management measures that will achieve load reductions and targeted critical areas
  4. Estimate amounts of technical and financial assistance and the relevant authorities needed to implement the plan
  5. Develop an information/education component
  6. Develop a project schedule
  7. Describe the interim, measurable milestones
  8. Identify indicators to measure progress
  9. Develop a monitoring component

While many of these elements have been indirectly addressed to varying degrees in the original Restoration Plan, in order to maximize Greenwood Lake’s opportunities to obtain State and Federal funding for the design and implementation of watershed control measures, the WIP now explicitly correlates the nine elements to eight specific deliverables, which are as follows:

  1. Conduct a detailed in‐lake and watershed‐based water quality monitoring program and compare the data to that collected in 2004 and 2005 to document changes or shifts in water quality.
  2. Meet with the Township of West Milford, Passaic County and other stakeholders to
    inventory recently completed BMPs and other watershed management measures.
  3. Conduct a field‐based evaluation of the stormwater project completed since the original 319‐grant funded Restoration Plan.
  4. Conduct site assessments to identify other potential stormwater/watershed BMP projects.
  5. Conduct a field assessment of the Belchers Creek Corridor to identify potential Nonpoint Source Pollution Reduction Projects.
  6. Assemble the WIP with all the 9 elements fully satisfied.
  7. Schedule and implement stakeholder and public meetings to evaluate project status.
  8. Submit of final version of WIP to the NJDEP and present the findings and recommendations to the public.

This project was initiated in September 2018 and is projected for completion by September 2019. The Greenwood Lake Commission, serves as the inter‐State steward of the Greenwood Lake watershed, and is working closely with Princeton Hydro and the watershed stakeholders (Township of West Milford, Passaic County and others), to ensure the WIP is a holistic document.

Stay tuned for more Greenwood Lake updates as the WIP progresses. For more information about Princeton Hydro’s lake management projects and capabilities, or to discuss your project needs and goals, please contact us.

Some of the photos utilized in this blog are from The Village of Greenwood Lake.

June 5: Restoration Ecology Course at Rutgers University

Join us on Wednesday, June 5 for a One-Day Environmental Training Course

Rutgers Office of Continuing Professional Education is offering a one-day class that explores the utilization of mitigation and sustainable design techniques to reduce stormwater impacts and increase storm resiliency.

The course, designed for ecologists, engineers, planners, and landscape architects involved in the recovery of impacted river, lake, riparian, wetland, and coastal environments, draws heavily upon real-world examples of restoration ecology in practice. This interactive course focuses specifically on the multi-disciplined recovery of degraded, damaged, or impaired ecosystems.

Dr. Stephen Souza, a founding principal of Princeton Hydro and owner of Clean Waters Consulting, LLC, is the main instructor and course coordinator. The course curriculum includes lessons from Dr. Souza and a number of experts from the Princeton Hydro team, including:

  • “River Restoration – Large Scale Dam Removal” lead by President Geoffrey Goll, P.E.
  • “Restoration of Tidal Ecosystems – The Creation of the Bayonne Golf Club” lead by Vice President Mark Gallagher
  • “Green Infrastructure and Coastal Resiliency” lead by Senior Project Manager & Environmental Scientist Christiana Pollack, GISP, CFM
  • “Does Green Infrastructure Mitigate Flooding?” lead by Dr. Souza

Course instruction will also be provided by John Miller, P.E., CFM, CSM, FEMA Mitigation Liaison; Nathaniel Burns, Langan Engineering Project Landscape Architect; and Capt. Al Modjeski, American Littoral Society Habitat Restoration Program Director.

In addition to 0.7 Rutgers CEUs, the course also awards participants with professional credits, including:

  • Landscape Architecture Continuing Education System (LA CES): 7.25 hours
  • NY Landscape Architects: 10.5 hours CL; 10 hours EA
  • NJ Public Health Continuing Education Contact Hours: 7.5
  • NJ Licensed Water & Wastewater Operators: 7 TCHs
  • NJ Certified Public Works Managers (CPWM): 5 Technical, 2 Government
  • NJ Licensed Professional Engineers: 6 Continuing Professional Competency (CPC) credits
  • NY Professional Engineers: 7 hours
  • NJ Licensed Site Remediation Professionals (LSRP): 6.5 Technical CEC’s

The course will be held on Wednesday, June 5 2019 from 8:30AM to 5:00PM at the Rutgers Continuing Education Center at the Atrium in Somerset, NJ. Register on or before May 22 to take advantage of a discounted early registration fee. Pre-registration is required. Continental breakfast and buffet lunch are provided at no additional cost.

Princeton Hydro is proud to partner with Rutgers Office of Continuing Professional Education and take part in this valuable continuing professional education course. We hope to see you there!

 

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

 

NJ SPOTLIGHT OP/ED Addresses the Creation of Stormwater Utilities in New Jersey

NJ Spotlight recently published an Op/Ed piece co-authored by Association of New Jersey Environmental Commissions (ANJEC) Board of Trustees members John A. Thonet, P.E., P.P., and Dr. Stephen J. Souza, PhD.

The piece asserts the position that New Jersey needs stormwater utilities to provide a sustained source of local funding in order to improve and maintain stormwater infrastructure in communities throughout the state.

We’ve included an excerpt from the Op/Ed below:

NJ SPOTLIGHT OP-ED: NEW UTILITIES WOULD HELP NEW JERSEY FIGHT FLOODING AND POLLUTION

2018 will be one of the wettest years on record for the Garden State, and all that rain has resulted in frequent flooding, millions of dollars in damages, gridlocked traffic, impacted drinking water and polluted waterways.

The problem is daunting, but there is a solution. For decades, the state has provided comprehensive planning and regulations aimed at protecting the public from the flooding impacts of improperly and inadequately managed stormwater. These efforts have helped but failed to address all the social, economic and environmental impacts associated with stormwater runoff. Today, rather than continuing to use conventional “collect, detain and discharge” approaches to controlling runoff, the use of “green infrastructure” is proving to be a better alternative. It’s focused on reducing runoff at its source, through recharge, reuse and evapotranspiration, rather than just treating it as a “waste” or “nuisance” to get rid of as quickly as possible.

Green infrastructure measures include porous pavement, green roofs, rain barrels, rain gardens, bioretention basins and other techniques designed to capture rainwater and allow it to soak into the ground instead of concentrating and discharging it downstream. Additionally, the “green infrastructure” approach is far more attractive and provides ecological and community benefits that can’t be achieved with standard detention basins.

So, what’s the hold-up? The answer is the absence of a sustained source of local funding to implement and maintain new stormwater infrastructure, including green infrastructure, as well as to retrofit, upgrade or replace failing existing stormwater management facilities…

Click Here to Read the Complete Op/Ed

 

About the Op/Ed Authors: 

John A. Thonet, P.E., P.P., is the president of Thonet Associates, Inc, an environmental, planning and engineering consulting firm based in Pittstown, NJ.

Dr. Stephen J. Souza, PhD is the owner of Clean Waters Consulting, LLC, a water resource consulting firm based in Ringoes, NJ that provides consulting services to Princeton Hydro, of which Steve is one of the founding principals.

Part Two: Reducing Flood Risk in Moodna Creek Watershed

Photo of Moodna Creek taken from the Forge Hill Road bridge, New Windsor Post Hurricane Irene (Courtesy of Daniel Case via Wikimedia Commons)

This two-part blog series showcases our work in the Moodna Creek Watershed in order to explore common methodologies used to estimate flood risk, develop a flood management strategy, and reduce flooding.

Welcome to Part Two: Flood Risk Reduction and Stormwater Management in the Moodna Creek Watershed

As we laid out in Part One of this blog series, the Moodna Creek Watershed, which covers 180 square miles of eastern Orange County, New York, has seen population growth in recent years and has experienced significant flooding from extreme weather events like Hurricane Irene, Tropical Storm Lee, and Hurricane Sandy. Reports indicate that the Moodna Creek Watershed’s flood risk will likely increase as time passes.

Understanding the existing and anticipated conditions for flooding within a watershed is a critical step to reducing risk. Our analysis revealed that flood risk in the Lower Moodna is predominantly driven by high-velocity flows that cause erosion, scouring, and damage to in-stream structures. The second cause of risk is back-flooding due to naturally formed and man-made constrictions within the channel. Other factors that have influenced flood risk within the watershed, include development within the floodplain and poor stormwater management.

Now, let’s take a closer look at a few of the strategies that we recommended for the Lower Moodna Watershed to address these issues and reduce current and future flood risk:

Stormwater Management

Damage to Butternut Drive caused when Moodna Creek flooded after Hurricane Irene (Courtesy of Daniel Case via Wikimedia Commons)

Stormwater is the runoff or excess water caused by precipitation such as rainwater or snowmelt. In urban areas, it flows over sewer gates which often drain into a lake or river. In natural landscapes, plants absorb and utilize stormwater, with the excess draining into local waterways.  In developed areas, like the Moodna Creek watershed, challenges arise from high volumes of uncontrolled stormwater runoff. The result is more water in streams and rivers in a shorter amount of time, producing higher peak flows and contributing to flooding issues.

Pollutant loading is also a major issue with uncontrolled stormwater runoff. Population growth and development are major contributors to the amount of pollutants in runoff as well as the volume and rate of runoff. Together, they can cause changes in hydrology and water quality that result in habitat loss, increased flooding, decreased aquatic biological diversity, and increased sedimentation and erosion.

To reduce flood hazards within the watershed, stormwater management is a primary focus and critical first step of the Moodna Creek Watershed Management Plan. The recommended stormwater improvement strategies include:

  • Minimizing the amount of impervious area within the watershed for new development, and replacing existing impervious surfaces with planter boxes, rain gardens and porous pavement.
  • Utilizing low-impact design measures like bioretention basins and constructed-wetland systems that mimic the role of natural wetlands by temporarily detaining and filtering stormwater.
  • Ensuring the long-term protection and viability of the watershed’s natural wetlands.

The project team recommended that stormwater management be required for all projects and that building regulations ensure development does not change the quantity, quality, or timing of run-off from any parcel within the watershed. Recommendations also stressed the importance of stormwater management ordinances focusing on future flood risk as well as addressing the existing flooding issues.

Floodplain Storage

Floodplains are the low-lying areas of land where floodwater periodically spreads when a river or stream overtops its banks. The floodplain provides a valuable function by storing floodwaters, buffering the effect of peak runoff, lessening erosion, and capturing nutrient-laden sediment.

Communities, like the Moodna Creek watershed, can reduce flooding by rehabilitating water conveyance channels to slow down the flow, increasing floodplain storage in order to intercept rainwater closer to where it falls, and creating floodplain benches to store flood water conveyed in the channel.  Increasing floodplain storage can be an approach that mimics and enhances the natural functions of the system.

One of the major causes of flooding along the Lower Moodna was the channel’s inability to maintain and hold high volumes of water caused by rain events. During a significant rain event, the Lower Moodna channel tends to swell, and water spills over its banks and into the community causing flooding. One way to resolve this issue is by changing the grading and increasing the size and depth of the floodplain in certain areas to safely store and infiltrate floodwater. The project team identified several additional opportunities to increase floodplain storage throughout the watershed.

One of the primary areas of opportunity was the Storm King Golf Club project site (above). The team analyzed the topography of the golf course to see if directing flow onto the greens would alter the extent and reach of the floodplain thus reducing the potential for flooding along the roadways and properties in the adjacent neighborhoods. Based on LiDAR data, it was estimated that the alteration of 27 acres could increase floodplain storage by 130.5 acre-feet, which is equivalent to approximately 42.5 million gallons per event.

Land Preservation & Critical Environmental Area Designation

For areas where land preservation is not a financially viable option, but the land is undeveloped, prone to flooding, and offers ecological value that would be impacted by development, the project team recommended a potential Critical Environmental Area (CEA) designation. A CEA designation does not protect land in perpetuity from development, but would trigger environmental reviews for proposed development under the NY State Quality Environmental Review Act. And, the designation provides an additional layer of scrutiny on projects to ensure they will not exacerbate flooding within the watershed or result in an unintentional increase in risk to existing properties and infrastructure.

Conserved riparian areas also generate a range of ecosystem services, in addition to the hazard mitigation benefits they provide. Protected forests, wetlands, and grasslands 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.


These are just a few of the flood risk reduction strategies we recommended for the Lower Moodna Creek watershed. For a more in-depth look at the proposed flood mitigation strategies and techniques, download a free copy of our Moodna Creek Watershed and Flood Mitigation Assessment presentation.

Revisit part-one of this blog series, which explores some of the concepts and methods used to estimate flood risk for existing conditions in the year 2050 and develop a flood management strategy.

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

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

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.

 

Barnegat “Clean Water, Beautiful Bay” Project wins Governor’s Environmental Excellence Award

The American Littoral Society was awarded the Governor’s Environmental Excellence Award in the Water Resources category this year for their Clean Water, Beautiful Bay projects in Barnegat Bay.

According to the Barnegat Bay Partnership, over 33% of the Barnegat Bay watershed has been altered to urban land cover. The construction of communities, roads and business has greatly increased the total amount of impervious surfaces in the watershed. With the added impervious cover has come a steady increase in the amount of nutrients, sediment, pathogens and other contaminants transported into the Bay by runoff. This accelerated the degradation of the Bay’s water quality and triggered changes to the Bay’s ecology.

Recognizing the importance of the Barnegat Bay, the American Littoral Society proposed green infrastructure measures to decrease runoff volume and nutrient loading to the bay and its tributaries.  Princeton Hydro was contracted by American Littoral Society to design four projects and provide oversight on the construction of the bioretention basins, rain gardens, porous pavement, etc. The projects were funded by the largest 319 grant ever administered by the NJDEP, totaling around $1 million. The project aimed to:

  1. Improve the water quality of Barnegat Bay by reducing the influx of nitrogen and other pollutants originating from the Long Swamp Creek and Lower Toms River watersheds. And, therefore, improve the water quality of both Long Swamp Creek and Lower Toms River, thus moving them closer to removal from the NJDEP’s 303D list of impaired waters.
  2. Demonstrate that relatively low-cost, stormwater system retrofits are capable of decreasing runoff volume, increasing stormwater recharge, and removing nutrients, and can be effectively implemented in even highly developed watersheds.
  3. Educate the public, elected and appointed officials and public work personnel of the types and benefits of bioretention, biodetention and infiltration stormwater management techniques.

From our team, Dr. Steve Souza and Paul Cooper worked to develop a unique Scoring Matrix for the selection of best management practices for retrofit projects. They have been asked several times to present on the matrix and demonstrate how to beneficially utilize it. In addition to design, Princeton Hydro participated in much of the public outreach for these projects, including giving presentations, leading workshops, and helping high school students plant vegetation around their school.

RWJ Barnabas Community Medical Center Educational Sign

According to NJDEP, the Clean Water, Beautiful Bay projects were successful in reducing flooding in a private residential homeowner community, improving a stormwater basin and public open space area at a hospital, introducing golf course staff and golfers to environmentally friendly golf course management practices, and engaging high school students in planting projects on school property.  The projects demonstrated that green infrastructure construction projects can reduce flooding and water pollution at business, community, school and public recreation locations, and can be publicly accepted and valued for the environmentally protective and restorative benefits they provide to Barnegat Bay.

Last year, the American Littoral Society’s Barnegat Bay Green Infrastructure Project was named “Project of the Year” by The American Society of Civil Engineers Central Jersey Branch.

For more information on Princeton Hydro’s green infrastructure and stormwater management services, please visit: bit.ly/stormwatermgmt 

Understanding and Implementing Green Infrastructure

By Tucker Simmons and Dr. Clay Emerson, PE, CFM

People generally think of green infrastructure as an eco-friendly way to handle stormwater runoff. While many green infrastructure elements are planned and managed specifically for stormwater control, the capabilities and benefits are far reaching. In this piece, we’ll provide an in-depth look at all that green infrastructure encompasses, best practices, and real-world examples of green infrastructure projects in action.

WHAT IS GREEN INFRASTRUCTURE?

Defined as an approach to water management that protects, restores, or mimics the natural water cycle, green infrastructure can be implemented for large scale projects and small scale projects alike.

Unlike conventional, or “gray” infrastructure, green infrastructure uses vegetation, soil, and other natural components to manage stormwater and generate healthier urban environments. Green infrastructure systems mimic natural hydrology to take advantage of interception, evapotranspiration and infiltration of stormwater runoff at its source. Examples include permeable pavers, rain gardens, bioretention basins, rain barrels, and tree boxes.

WHY IS GREEN INFRASTRUCTURE BENEFICIAL?

Green infrastructure provides various benefits, including cleaning and conserving water, reducing flooding, improving public health, providing jobs, beautifying neighborhoods, supporting wildlife and providing economic benefits at both the larger community and individual household level. Let’s take a closer look at some of the primary benefits:

Prevents Flooding: By absorbing and slowing the flow of water, green infrastructure can reduce the burden on storm sewer systems and mitigate localized flooding.

Saves Money: While some green infrastructure designs may require the same or greater initial investment than conventional strategies, green design methods provide a big return in reducing costs over the long-term.

Improves Water Quality: Through natural absorption and filtration processes, green infrastructure significantly reduces stormwater runoff volume, decreases the pollutants and particulates within the stormwater, and improves the quality of the runoff flowing into surrounding water bodies.

Improves Air Quality: Green infrastructure techniques like tree boxes, green roofs and vegetative barriers have long been associated with improving air quality. Urban tree boxes help shade surfaces, effectively putting moisture into the air while reducing greenhouse gases. Trees mitigate heat and air pollution, both cooling and cleaning the air.

Enhances Aesthetics: Many green infrastructure practices utilize native plants and trees to improve runoff absorption and reduce stormwater pollution. This vegetation can provide a sound barrier or privacy screen for properties, and enhances the overall aesthetics of the surrounding environment. 

Increases Property Values: Research shows that property values increase when trees and other vegetation are present in urban areas. Planting trees can increase property values by as much as 15%.

LARGE-SCALE GREEN INFRASTRUCTURE IMPLEMENTATION:

With the use of proper design techniques, green infrastructure can be applied almost anywhere and is especially beneficial in urban areas. In developed environments, unmanaged stormwater creates two major issues: one related to the volume and timing of stormwater runoff (flooding) and the other related to pollutants the water carries. Green Infrastructure in urban environments can recharge groundwater, decrease runoff, improve water quality, and restore aquatic habitats while controlling flooding.

Across the United States, more than 700 cities utilize combined sewer systems (CSS) to collect and convey both sanitary sewage and stormwater to wastewater treatment facilities. During dry weather, all wastewater flows are conveyed to a sewage treatment plant where it receives appropriate treatment before it is discharged to the waterway. However, during heavy rainfall or significant snowmelt, the additional flow exceeds the capacity of the system resulting in a discharge of untreated sewage and stormwater to the waterway; this discharge is referred to as a combined sewer overflow (CSOs). For many cities with CSS, CSOs remain one of the greatest challenges to meeting water quality standards. Green infrastructure practices mimic natural hydrologic processes to reduce the quantity and/or rate of stormwater flows into the CSS.

New Jersey, as part of the 2012 USEPA’s Integrated Municipal Stormwater and Wastewater Planning Approach Framework, utilized green infrastructure as one of the main components in managing its CSS and reducing CSOs. Because of the flexibility of green infrastructure in design performance, it can reduce and mitigate localized flooding and sewer back-ups while also reducing CSOs. An integrated plan that addresses both overflows and flooding can often be more cost-effective than addressing these issues separately. New Jersey, in addition to meeting its CSO reduction goals, is using green infrastructure throughout the sewershed to build resilience to large storm events and improve stormwater management.

Stormwater planters installed by the Philadelphia Water Department

Philadelphia takes advantage of numerous green stormwater infrastructure programs such as Green Streets, Green Schools, and Green Parking. There are a wide variety of green infrastructure practices that Philadelphia is using to decrease stormwater runoff throughout the entire city. After just five years of implementing the Green City, Green Waterplan, Philadelphia has reduced the stormwater pollution entering its waterways by 85%. Using over 1,100 green stormwater tools (i.e. CSO, living landscapes, permeable surfaces, etc.), in just one year, Philadelphia was able to prevent over 1.7 billion gallons of polluted water from entering their rivers and streams.

New York City is using a green infrastructure program, led by its Department of Environmental Protection, that utilizes multiple green infrastructure practices to promote the natural movement of water while preventing polluted stormwater runoff from entering sewer systems and surrounding waterbodies. While attaining this goal, the green infrastructure also provides improvements in water and air quality, as well as improves the aesthetics of the streets and neighborhoods. According to the NYC Green Infrastructure Plan, “By 2030, we estimate that New Yorkers will receive between $139 million and $418 million in additional benefits such as reduced energy bills, increased property values, and improved health.”

SMALL-SCALE GREEN INFRASTRUCTURE IMPLEMENTATION:

Green infrastructure techniques are extremely beneficial on every scale. Residential homes and neighborhoods can benefit from the implementation of green infrastructure in more ways than many people realize. There are a wide variety of green infrastructure projects that can be completed with a relatively small time and financial investment. Many of us at Princeton Hydro have incorporated green infrastructure practices into our homes and properties. Here’s a look at some of those projects in action:

Dr. Steve Souza, a founding principal of Princeton Hydro, installed rain gardens throughout his property utilizing native, drought-resistant, pollinator-attracting plants. The rain gardens are designed to capture and infiltrate rainwater runoff from the roof, driveway, patio and lawn.

Princeton Hydro’s President Geoffrey Goll, P.E. built an infiltration trench in his backyard. An infiltration trench is a type of best management practice (BMP) that is used to manage stormwater runoff, prevent flooding and downstream erosion, and improve water quality in adjacent waterways. 

And, in the front yard, Geoffrey installed a variety of wildflower plantings.

MUNICIPAL TOOLKIT

An interactive website toolkit was recently launched by New Jersey Future to help municipalities across the state incorporate green infrastructure projects into their communities. For this project, Princeton Hydro’s engineers and scientists provided real-world examples integrating green infrastructure into development in order to bring to light the benefits and importance of investing in green infrastructure at the local level. The New Jersey Green Infrastructure Municipal Toolkit provides expert information on planning, implementing, and sustaining green infrastructure to manage stormwater. This toolkit acts as a one-stop resource for community leaders who want to sustainably manage stormwater, reduce localized flooding, and improve water quality.

GET STARTED

Since its inception, Princeton Hydro has been a leader in innovative, cost-effective, and environmentally sound stormwater management systems. Long before the term “green infrastructure” was part of the design community’s lexicon, the firm’s engineers were integrating stormwater management with natural systems to fulfill such diverse objectives as flood control, water quality protection, and pollutant reduction. Princeton Hydro has developed regional nonpoint source pollutant budgets for over 100 waterways. The preparation of stormwater management plans and design of stormwater management systems for pollutant reduction is an integral part of many of the firm’s projects.

Interested in working with us on your next Green Infrastructure project? Contact us here.


Tucker Simmons, Water Resources Intern

Tucker is a Civil and Environmental Engineering major at Rowan University focusing on Water Resources Engineering. He is the President and player of the Rowan University Men’s DII Ice Hockey Team. His Junior Clinic experience includes the study of Bio-Cemented sand and the Remote Sensing of Landfill Fires. In the future, Tucker hopes to work on creating a more sustainable environment. Tucker enjoys playing ice hockey, being with friends and family, and exercising.

 

Clay Emerson, Senior Project Manager

Clay’s areas of expertise include hydrologic and hydraulic analysis, stormwater management and infiltration, nonpoint source (NPS) pollution, watershed modeling, groundwater hydrology/modeling, and water quality and quantity monitoring at both the individual site and watershed scales. His educational and work experience includes a substantial amount of crossover between engineering and environmental science applications. He has specific expertise in the field of stormwater infiltration and has conducted extensive research on the NPS pollution control and water quantity control performance of stormwater BMPs. He regularly disseminates his monitoring results through numerous peer-reviewed journal publications, magazine articles, and presentations.

 

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.

 

Deal Lake Commission Wins Award For “Lake Management Success”

NALMS President Dr. Frank Browne with Princeton Hydro Co-Founder Dr. Stephen Souza accepting the “Lake Management Success Stories” award on behalf of the Deal Lake Commission.

The Deal Lake Commission’s success in the management and restoration of Deal Lake garners a prestigious award from the North American Lake Management Society

 

The North American Lake Management Society (NALMS) awarded the Deal Lake Commission (DLC) with its “2018 Lake Management Success Stories” award. The award, which was presented at the NALMS 38th International Symposium, is given annually to recognize and honor an individual or group that has made significant lake/reservoir management accomplishments.

The DLC has overseen the management and restoration of Deal Lake and its watershed since 1974. Consisting of appointees from the seven municipalities abutting the lake, the DLC’s mission is to provide leadership, guidance and resources to preserve and restore Deal Lake and its tributaries as a healthy and stable ecosystem. A true challenge in an urban environment.

“It has been both a pleasure and an honor to work with the Deal Lake Commission for the past 35 years,” said Dr. Stephen Souza, Princeton Hydro Co-Founder. “They have shown great resolve to tackle some serious problems affecting the lake and its watershed, serving as a great example for other organizations involved in the restoration of urban lakes.”

Deal Lake is New Jersey’s largest coastal lake, encompassing 162 acres. The lake is surrounded by a 4,400-acre highly urbanized watershed, with the majority of development dating back to the 1960s-1980s. As a result, stormwater management, particularly with respect to water quality and volume management can be especially challenging. The DLC has embraced the numerous challenges, and has worked diligently over the years to correct these issues.

Restored shoreline at the Asbury Park Boat Launch in Deal LakeAt the forefront, the DLC has been managing the primary cause of the lake’s eutrophication: stormwater runoff from the surrounding watershed. In 2014, with funding provided through the NJDEP’s 319(h) program, the DLC implemented a number of demonstration projects, specifically the construction of three bioretention basins, the installation of a large manufactured treatment device, the vegetative stabilization of over 500 feet of heavily eroded sections of the shoreline, and the construction of a rain garden at the Deal Lake boat launch.

Collectively these projects were shown to eliminate localized flooding, decrease floatable loading, and reduce nutrient, sediment and pathogen inputs to the lake. These and other projects implemented by the DLC over the years show that despite Deal Lake being located in a highly urbanized watershed, it is possible to implement cost-effective green infrastructure and stormwater retrofit solutions.

Deal Lake recently won another very competitive 319 (h) program for $735,000 for MTDs, tree boxes, and Green infrastructure improvements to Deal Lake, Sunset Lake and Wesley Lake.

The NALMS award nomination application, which was submitted by Dr. Souza, listed a number of additional achievements of the DLC, including:

  • Educating the community, including school children, to increase awareness and appreciation for the natural environment of the lake;
  • Sponsoring and conducting public engaged spring and fall cleanups, which annually result in the removal of 1,000s of pounds of refuse and debris from the lake;
  • Helping homeowners and public groups recognize and mindfully solve problems related to water quality, siltation, and lake restoration;
  • Serving as the liaison between lakeside communities, County agencies, and the NJDEP;
  • Microbial source tracking investigations with Monmouth University and pathogen source identification work with Clean Ocean Action to decrease E. coli loading;
  • Carp removal, invasive species management, and goose control initiatives;
  • Working with State legislators to implement stricter stormwater controls to reduce pollutant loading, increase storm resiliency, and improve recreational fishing;
  • Participating in the NALMS Secchi Dip In; and
  • Proactively suggesting and supporting community-based, practical ideas to improve the overall environmental quality of the lake and its enjoyment by boaters, anglers, hikers, residents and visitors.

For more information on the Deal Lake Commission, visit DealLake.org.

The successful, long-term improvement of a lake or pond requires a proactive management approach that addresses the beyond simply reacting to weed and algae growth and other symptoms of eutrophication. Our staff can design and implement holistic, ecologically-sound solutions for the most difficult weed and algae challenges. Visit our website to learn more about Princeton Hydro’s lake management services: http://bit.ly/pondlake.