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.

 

Winter Events Spotlight: Environmental Conferences & Classes

Over the coming months, Princeton Hydro is teaching courses and presenting at a variety of conferences that explore topics ranging from wetland restoration to cyanotoxins to dam removal:

 

January 2019 – May 2019: Temple University Wetland Ecology Course

Our Vice President Mark Gallagher, along with Founding Principal and Consultant Dr. Steve Souza, is teaching an applied wetland ecology graduate course at Temple University. The 17-week spring semester course, which includes weekly lectures as well as field trips, will provide students with an opportunity to study real-world examples of wetland and riparian restoration and the integration of wetland ecology and restoration design within the context of green infrastructure.

Students will gain an increased understanding of the ecological functions of wetland and riparian ecosystems; be introduced to the principles of applied ecology as related to wetland and riparian ecosystem restoration; learn about the application of wetland ecology in landscape restoration and enhancement projects; get hands-on experience with how to use green infrastructure techniques in urban and suburban settings to control and abate stormwater impacts; and learn about related state and federal rules and regulations.

LEARN MORE

 

January 2019 – May 2019: Delaware Valley University Watershed Management Course

Beginning January 22, Dr. Fred Lubnow, our Director of Aquatic Programs, is teaching a spring semester “Watershed Management” course at Delaware Valley University. Through hands-on laboratory exercises and engaging lectures, the course provides participants with the foundational skills needed to understand the concepts and terminology of hydrologic processes and watersheds. The concepts and processes include evapotranspiration, soil water, infiltration, runoff, and stream flow. Students will also develop skills in environmental awareness, ecological awareness, and land stewardship, which will help them understand the key processes involved in managing watershed resources sustainably.

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January 27-30, 2019: Delaware Estuary Science and Environmental Summit, Cape May, NJ

Every two years, the Partnership for the Delaware Estuary holds a summit that focuses on developing practical solutions to challenges facing our tidal Delaware River and Bay. This year, the theme is Estuary 2029: Saving Our System Through Collaboration. Our Communications Strategist, Dana Patterson, is presenting “Strategic Science Communication & Stakeholder Engagement in the Delaware Estuary” during the Strategic Science Communication Session on Monday, January 28th. 

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March 6-7, 2019: Pennsylvania Lake Management Society’s 29th Annual Conference

This two-day conference covers a wide range of topics such as invasive aquatic plant identification and eradication, harmful algal blooms (HABS), case studies of publicly funded projects and stewardship programs, management or remediation techniques, habitat or fishery improvement, and chemical application techniques. Core and category credits are available for professional chemical applicators for many of the presentations.  We’re proud to sponsor this conference year after year.  Dr. Fred Lubnow, Princeton Hydro’s Director of Aquatic Programs, is giving a presentation about utilizing a watershed implementation plan to address both the external and internal phosphorus loads for Lake Carey, Pennsylvania.  Come visit our booth and say hello to our Aquatics team members. BONUS: Every full conference registration also includes one free year of PALMS membership.

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March 9, 2019: Watershed Congress Along the Schuylkill River

Hosted by the Delaware Riverkeeper Network, this conference is a highly anticipated event for people in the Schuylkill Watershed and beyond interested in understanding, protecting, and restoring their local streams and watersheds. Princeton Hydro is a proud sponsor and exhibitor of this conference. Come check out an hour-long, dynamic session on “Using Values-Driven Communication Strategies To Engage Your Watershed,” hosted by our Communications Strategist, Dana Patterson.

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March 22, 2019: The Pennsylvania Water Works Association’s Northeast District Spring Meeting

The PA-AWWA Northeast District and the Water Works Operators’ Association of Pennsylvania Eastern Section are hosting a Spring 2019 Meeting, which will cover a range of technical topics related to water resource management. Dr. Fred Lubnow is teaching a three-hour course on the monitoring and management of cyanotoxins in sources of raw water.

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Also, Coming Up This Spring:
April 12, 2019: New Jersey Land Conservation Rally

Conservation Innovations in a Changing World is the theme this year for the 23rd Annual NJ Land Conservation Rally. We’re excited to sponsor this one-day educational conference about preserving open space and farmland in New Jersey. Start your morning off with a dynamic marketing session, “Nonprofit Storytelling A-Z: How to Transform Passive Clickers into Action Takers,” hosted by Princeton Hydro’s Communications Strategist, Dana Patterson and National Audubon Society‘s Mid-Level Giving Manager, Lindsay McNamara.  Check out a great afternoon session with our Aquatics Director, Dr. Fred Lubnow, and Senior Aquatic Scientist, Dr. Dr. Jack Szczepanski, who will offer tips on, “The Monitoring and Management of Cyanotoxins in Recreational Lakes and Managing Your Lake’s Fisheries.” And, don’t forget to say “hello” to all of our staff at our exhibitor booth during the conference.

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April 12, 2019: Environmental Business Council of New England Meeting

Princeton Hydro recently joined as a business member of the Environmental Business Council (EBC) of New England, a nonprofit organization dedicated to enhancing business and job growth of both established and emerging environmental and energy businesses. EBC provides member companies with an array of programs, activities, and information to enable them to stay on the cutting edge of environmental and energy technologies, management and regulatory developments. At this EPC meeting, our Director of our New England office, Laura Wildman, PE, and Fluvial Geomorphologist, Paul Woodworth, are hosting a workshop for members on “Dam Removal and Sediment Management.”

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STAY TUNED FOR MORE EVENT SPOTLIGHTS!

Employee Spotlight: Meet Our New Team Members

We’re excited to welcome four new members to our team. The addition of this group of talented individuals strengthens our commitment to delivering great service that exceeds our clients’ expectations.

Meet Our New Team Members
Miranda Lepek, EIT, Water Resource Engineer

Miranda is a civil engineer with expertise in grading and stormwater design, CAD drafting, environmental sampling, and construction oversight. Prior to Princeton Hydro, she worked for a small site development firm in Michigan where she developed her drafting skills and facilitated multiple aspects of private and commercial land development projects.

Miranda holds a B.S. in Civil Engineering from the University of Michigan – Ann Arbor. While on study abroad, she contributed to the one of the longest-running native amphibian field studies in New Zealand. In other previous experiences, she worked on major projects including the investigation phases of a Superfund site cleanup in Duluth, MN and a comprehensive sampling operation over 40 miles of the Hudson River near Albany, NY. In her free time, Miranda enjoys hiking, foraging, cooking and art.

Sumantha Prasad, PE, ENV SP, Water Resource Engineer

Sumantha is a Water Resource Engineer with a B.S. in Bioenvironmental Engineering from Rutgers University and a M.S. in Environmental Engineering and Science from Johns Hopkins University. She worked in Maryland for seven years focusing on ecological restoration projects, including stream restoration, wetland creation and enhancement, and stormwater management, and she worked for 3 years with a primary focus on highway hydrology and hydraulics.

In her spare time, she enjoys being a Toastmaster and serves as the Treasurer to a 501(c)3 organization dedicated to creating inclusive housing communities for adults with disabilities. She also enjoys telling terrible puns unapologetically.

Pat Rose, Environmental Scientist

Pat’s interest in aquatics began during a summer course studying at Lake Atitlán, Guatemala as an undergraduate at SUNY Oneonta. After graduation, he spent a year volunteering with AmeriCorps in Knoxville, Tennessee as part of a Water Quality Team. While in Tennessee, Pat spent the majority of his time educating high school students on how to protect and improve local waterways and watersheds as part of the Adopt-A-Watershed program. During his year with AmeriCorps, Pat worked with government organizations to perform biological sampling and erosion monitoring in local streams.

Pat graduated from SUNY Oneonta with a M.S. in Lake Management in December 2018. During his time in graduate school, he created an interim lake management plan for a small reservoir in New York that has had cyanobacterial blooms over the past few years. Pat spent this past summer completing a co-op with an aquatic plant management company in the Pacific Northwest, working primarily with invasive Eurasian and hybrid watermilfoil populations.

Duncan Simpson, Senior Environmental Scientist

For nearly a decade, Duncan has served as an Environmental Scientist/Planner in the Mid-Atlantic Region. His experience includes a wide range of natural resource studies, documentation, and permitting at both the project and program level. He has special expertise in wetlands; Waters of the US delineations; and permitting for stormwater management facilities, stream restoration, and TMDL program projects. He has conducted forest stand delineations; rare, threatened and endangered species consultations; mitigation monitoring; and National Environmental Policy Act (NEPA) documentation.

Duncan holds an M.S in Biology from Towson University and a B.S. in Environmental Science with a Wildlife and Fisheries Conservation Minor from the University of Massachusetts. During his graduate studies, he researched amphibian species found in Delmarva Bays and testing models that predict their presence based on abiotic habitat characteristics. He also served as a student member of the Northeast Partners in Amphibian and Reptile Conservation (NEPARC) steering committee. Duncan is a Professional Wetland Scientist and member of the Society of Wetland Scientists. In his spare time, he enjoys hiking with his dog and learning how to fly fish.

 

Our D.C. Regional Office is Moving!

New year, new office! Next week, our D.C. Regional office is moving from its current location in Annapolis, Maryland to a new office space just 14 miles away in Bowie, Maryland. We are excited for a change of scenery and the opportunity to grow our space. 

“We are very excited to relocate our office to Bowie, Maryland. This move will continue to increase our presence in Maryland, provide centralized access to our clients, and create new opportunities for the DC/Baltimore region,” said Princeton Hydro President, Geoffrey Goll, PE.

The new space is located between Annapolis, MD and Washington DC, only a 15-minute drive to both cities. This new spot will help us further strengthen our relationships in Washington, DC and with Prince George’s County.

Our new address is 4201 Northview Drive, Suite 314, Bowie, MD 20716.