Levee Inspections Along the Elizabeth River

Ursino Dam on the Elizabeth River in Union County, New Jersey is one of the sites Princeton Hydro inspected for flood control, ensuring the system is providing the level of protection it was designed to deliver.

By Brendon Achey, Princeton Hydro’s Lead Geologist; Soils Laboratory Manager; Project Manager

Located 20 miles southwest of New York City, the City of Elizabeth, New Jersey, is situated along the Elizabeth River. For the city’s 125,000 residents, living along the river has many benefits, but the benefits are not without flood risk. In order to manage the risk associated with potential flooding, a series of levees and floodwalls were installed along the banks of the Elizabeth River. A levee is an embankment that is constructed to prevent overflow from a river. They are a crucial element for protecting cities from disastrous flooding, and as such they require periodic inspections to ensure that all components are functioning properly.

Princeton Hydro was contracted by the U.S. Army Corps of Engineers, New York District (USACE NYD) to perform rigorous flood control project inspections (i.e., “Periodic Inspections”) for the four levee systems located along the Elizabeth River.  For this project, our team inspected over 17,000 linear feet of levee embankment and 2,500 linear feet of floodwall.

Levee systems are comprised of components which collectively provide flood risk management to a defined area. These components can include levees, structural floodwalls, closure gates, pumping stations, culverts, and interior drainage works. These components are interconnected and collectively ensure the protection of development and/or infrastructure that is situated within a floodplain. Failure of just one critical component within a system could constitute an overall system failure. During Hurricane Katrina, for example, dozens of levees were destroyed, leaving the Louisiana coast with billions of dollars in damage and over one thousand lives lost.

Periodic inspections are necessary in order to ensure a levee system will perform as expected. They are also needed to identify deficiencies in the levee, or areas that need monitoring or immediate repair. Critically important maintenance activities include continuously assessing the integrity of the levee system to identify changes over time, collecting information to help inform decisions about future actions, and providing the public with information about the levees on which they rely.

Levee Inspection Process

Periodic inspections are extremely comprehensive and include three key steps: data collection, field inspection, and development of a final report.

Data Collection

Prior to conducting field inspections, Princeton Hydro’s engineers evaluated the Elizabeth River levee system’s documented design criteria. This evaluation was conducted to assess the ability of each feature and the overall system to function as authorized, and also to identify any potential need to update the system design. Princeton Hydro teamed with HDR to carry out the inspections. A comprehensive review of existing data on operation and maintenance, previous inspections, emergency action plans, and flood fighting records was also performed.

Field Inspection

The Princeton Hydro field inspection team consisted of geotechnical, water resource, mechanical, structural, and electrical engineers. Detailed inspections were performed on each segment of each levee system.  This included the detailed inspection and documentation of over 17,000 linear feet of levee embankment, over 2,500 linear feet of floodwall, four pumping stations, 29 interior drainage structures, five closure gates, and various other encroachments and facilities. Princeton Hydro identified, evaluated, and rated the state of each of these system elements. As part of this field inspection task, Princeton Hydro utilized a state-of-the-art tablet and GIS technology in order to field-locate inspection points and record item ratings. This digital collection of data helps expedite data processing and ensures higher levels of accuracy.

Development of Final Report

Princeton Hydro prepared a Periodic Inspection Report for each of the four levee systems inspected, which included the results of the design document review, methods and results of the field inspection, a summary of areas/items of concern, a preliminary engineering assessment of causes of distress or abnormal conditions, and recommendations for remedial actions to address identified concerns. Final report development included briefing the USACE Levee Safety Officer (LSO) on our inspection findings, assigned ratings, and recommendations.

Levee inspections are vital to the longevity of levee systems and the safety of the communities they protect. By providing the municipalities with detailed inspection reports, effective repair and management programs can be designed and implemented efficiently. This helps to ensure the levee systems are providing the level of protection that they were designed to deliver.

Princeton Hydro’s Geoscience and Water Resource Engineering teams perform levee and dam inspections throughout the Mid-Atlantic and New England Regions. For more info, visit: http://bit.ly/PHEngineering

Brendon Achey provides a wide range of technical skills and services for Princeton Hydro. His responsibilities include: project management, preparation and quality control of technical deliverables, geotechnical investigations and analysis, groundwater hydrology, soil sampling plan design and implementation, and site characterization. He is responsible for managing the daily operations of the AASHTO accredited and USACE validated soil testing laboratory. In addition to laboratory testing and analysis, Brendon is responsible for analyzing results in support of geotechnical and stormwater management design evaluations. This may include bearing capacity and settlement analysis of both shallow and deep foundations, retaining wall design, and recommendations for stormwater management practices.

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.

Stay tuned for Part Two of this blog series in which we will explore flood risk-reduction strategies that include both traditional engineering and natural systems solutions. For more information about Princeton Hydro’s flood management services, go here: http://bit.ly/PHfloodplain.

 

November Events Spotlight: Conferences Throughout the Country

Princeton Hydro is participating in a variety of conferences taking place throughout the country that address topics ranging from lake management to green infrastructure resiliency:

October 30 – November 2: North American Lake Management Society (NALMS) Conference

NALMS is hosting its 38th International Symposium in Cincinnati Ohio, titled “Now Trending: Innovations in Lake Management.” This year’s symposium includes a robust exhibit hall, a variety of field trips, and a wide array of presentations on topics ranging from the latest in monitoring technologies to combating invasive species to nutrient and water quality management and more. Princeton Hydro’s Dr. Fred Lubnow, Director of Aquatic Programs, and Dr. Stephen Souza, Founder, both of whom have been members of NALMS since its inception, are presenting and exhibiting during the conference.

LEARN MORE

 

October 31 – November 2: Society for American Military Engineers (SAME) Small Business Conference (SBC)

SAME gives leaders from the A/E/C, environmental, and facility management industries the opportunity to come together with federal agencies in order to showcase best practices and highlight future opportunities for small businesses to work in the federal market. Princeton Hydro is proud to be attending the 2018 SAME SBC Conference, which is being held in New Orleans and co-locating with the Department of Veteran’s Affairs’ National Veterans Small Business Engagement. The program consists of networking events, small business exhibits, a variety of speakers and much more.

LEARN MORE & REGISTER

 

November 2: The 2nd Annual New Jersey Watershed Conference

We are a proud sponsor of this year’s New Jersey Watershed Conference, which is an educational event that aims to advance knowledge and communications on issues related to water quality and quantity across the state. The agenda features a variety of presentations from local experts on watershed management, stormwater, green infrastructure, and the problems and solutions related to the health of our watersheds. Princeton Hydro is exhibiting & our Marketing Coordinator, Kelsey Mattison, is leading a workshop on “How Social Media can be a Champion for your Watershed.”

LEARN MORE & REGISTER

 

November 4 – 8: 2018 American Water Resources Association Conference

The AWRA’s 53rd Annual Water Resources Conference is being held in Baltimore, MD. Community, conversations and connections are highlights of every AWRA conference and the 2018 conference will provide plenty of opportunities for all three, including an exhibitor hall, networking events, and variety of presentations and technical sessions. Princeton Hydro’s Christiana Pollack, GISP, CFM is giving a presentation on flood assessment and mitigation. 

LEARN MORE & REGISTER

 

November 8 – 10: Engineers Without Borders (EWB) USA Conference

The EWB, a nonprofit humanitarian organization that partners with developing communities worldwide in order to improve their quality of life, is hosting its USA National Conference in San Francisco.  The ​annual ​conference ​will ​address ​the ​theme ​“Engineers Unlock Potential.” ​Experts, ​practitioners, ​decision-makers, ​young ​professionals ​and ​students ​from ​a ​range ​of ​sectors ​will come together to network, exchange ideas, foster new thinking and develop solutions to the world’s most pressing infrastructure ​challenges. Princeton Hydro Staff Engineer Natalie Rodrigues, EIT, CPESC-IT, a EWB member, is attending the conference and presentation. Her session, titled “So You Think You Might Like to be an EWB Regional Officer or State Representative, ” is designed for those interested in taking the next step beyond Chapter or Project participation at EWB-USA, as well as for current Regional Steering Committee members who want to “amp up” their game.

LEARN MORE & REGISTER

 

November 13: Society for American Military Engineers (SAME) Philadelphia Resiliency Symposium

SAME Philadelphia is hosting an all day symposium featuring experts on infrastructure resiliency in the face of extreme storms, flooding and other natural disasters. Presentation topics include, Flood Hazard Risk and Climate Change Effects for Bulk Oil Storage Facilities; Post-Storm Infrastructure Improvements and Stream Restoration; and Resilience Risk Analysis and Engineering. Princeton Hydro President Geoffrey Goll, P.E. is giving a presentation titled, “Enhancing Coastal Habitat & Increasing Resiliency through Beneficial Reuse of Dredged Material in New Jersey.” We hope to see you there!

LEARN MORE & REGISTER

 

November 16: NJ Chapter American Water Resources Association (NJ-AWRA) Future Risk Symposium

As the frequency and intensity of storm events changes, how should watershed managers, engineers, and planners make informed decisions for the future? NJ-AWRA’s 2018 Future Risk Symposium, held at Duke Farms in Hillsborough, NJ, will focus on Future Flooding in Riverine Systems with presentations on climate trends, modeling, and planning that can be used in NJ to prepare for future flood events in New Jersey’s riverine systems. Princeton Hydro’s Christiana Pollack, GISP, CFM is giving a presentation on flood assessment, and the concepts and methods used to estimate flood risk for existing conditions and the year 2050.

LEARN MORE & REGISTER

 

STAY TUNED FOR MORE EVENT SPOTLIGHTS!

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

Employee Spotlight: Meet Our New Team Members

We’re excited to welcome two new staff members and seven new part-time staff & interns to our team who are spread throughout our Ringoes, Sicklerville, and Glastonbury offices.

 

Full-Time Staff Members:
Kelsey Mattison, Marketing Coordinator

Kelsey 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, she has developed expertise in social media management, content writing, storytelling, and interdisciplinary thinking. Kelsey believes that effective communication needs to be multi-faceted, which is reflected in the diversity of her experience. She served as Photography Editor of St. Lawrence University’s newspaper, worked in digital media for the environmental outreach program of St. Lawrence University,  produced stories for Northern New York’s public radio station, and developed feature content for St. Lawrence County’s Chamber of Commerce. 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. In her free time, Kelsey enjoys dancing of all sorts, going on long walks with her camera, and spending time with friends and family in nature.

Christine Worthington, Accounting Assistant

Christine is a detailed-oriented Accounting Assistant who has over 15 years of experience working in office administration for local businesses. She loves vacationing in Jamaica with her husband and spending time with her two sons & three grandchildren. In her free time, she listens to country music and visits new cities like Nashville.

 

Part-time Staff, Field Assistants & Interns:
Heidi Golden, PhD, Aquatic Ecologist

Heidi is an aquatic ecologist and evolutionary biologist with a strong background in fish monitoring, aquatic habitat assessment, population and community ecology, and population genetics and genomics. She holds a PhD in Ecology and Evolutionary Biology and a Master of Science in Forestry and Wildlife Biology. In addition to her ecology expertise, Heidi has experience in GIS analysis, R statistical programing, scientific writing, permitting, and a wide range of field and laboratory techniques. Prior to joining Princeton Hydro, Heidi worked as a postdoctoral researcher with The Woods Hole Research Center, The Marine Biological Laboratory, and The University of Connecticut, where she continues to serve as adjunct faculty to the Department of Ecology and Evolutionary Biology. She investigated ecological and evolutionary responses of fish populations to rapid environmental change. Her professional experience also includes coordinating field expeditions in remote locations of the Alaskan Arctic, tagging and tracking thousands of fish through remote PIT-tag antenna arrays, using environmental DNA to monitor fish presence and movement, and developing experiments to assess ecosystem responses to change. She enjoys raising ducks, swimming in cold rivers, hiking, kayaking, camping, and family.

Andrew Greenlaw, Water Resources Intern

Andrew Greenlaw is in his fourth year at the University of Connecticut, majoring in Civil Engineering with a minor in Environmental Engineering. Before studying engineering he taught at a Marine science summer camp in Groton, CT, off of the Long Island Sound. He joined Princeton Hydro with the hope of combining his biological sciences experience with his academic engineering knowledge. He enjoys hiking, fishing, and just about any outdoor sport.

Ryan Lindsay, Water Resources Intern

Ryan is a double major at Rowan University focusing in both Civil & Environmental Engineering and Computer Science, and is currently finishing his final semester. He’s worked on various engineering clinic projects ranging from developing a pavement analysis program for Rhode Island DOT to a feasibility study to assist those with disabilities. His current project is to develop a home security/monitoring system with an accompanying mobile application. In the future, Ryan hopes to develop civil engineering applications for use by design engineers, and hopes that with his unique skillset he can make future engineers’ jobs easier and more efficient. Ryan enjoys playing baseball, listening to music, hiking and hanging out with friends and family.

Nick Niezgoda, Aquatics Field Assistant

Nick graduated in 2017 from Western State Colorado University with a B.S. in Biology. He lived and worked at Rocky Mountain Biological Laboratory studying defense genotypes of B.stricta under Duke University’s Tom Mitchell-Olds Lab in 2016 and 2018. At RMBL, He also assisted in trapping and banding of Mountain White-Crowned Sparrows. He enjoys cycling, hiking, and birding!

Emily McGuckin, Aquatics Field Assistant

Emily is a recent graduate from Stockton University, with a BS in marine biology, and a minor in environmental science. She just finished up an internship with the American Littoral Society at Sandy Hook, where she helped manage the fish tagging program and educating others on the importance of maintaining an accurate fisheries database. She has experience in both freshwater and marine ecosystem management and is excited to continue learning about ecological restoration and management.  She is very interested in ecosystem resilience, specifically climate change and how it affects estuaries and estuarine organisms. Emily is hoping to attend graduate school in the near future to further her studies in marine science.

Pat Rose, Aquatics Field Assistant

Pat got interested in aquatics 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, TN as part of a Water Quality Team. While in Tennessee, he 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. The year, through AmeriCorps, he also worked with government organizations performing biological sampling and erosion monitoring in local streams. Pat is set to graduate from SUNY Oneonta with a M.S. in Lake Management in December. 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.

 

Dam Removal Underway in Watertown, Connecticut

Deconstruction of the Heminway Pond Dam, Watertown, CT on July 16, 2018.

As dams age and decay, they can become public safety hazards, presenting a failure risk and flooding danger. According to American Rivers, “more than 90,000 dams in the country are no longer serving the purpose that they were built to provide decades or centuries ago.” Dam removal has increasingly become the best option for property owners who can no longer afford the rising cost of maintenance and repair work required to maintain these complex structures.

Dams can also cause environmental issues such as blocking the movement of fish and other aquatic species, inundating river habitat, impairing water quality, and altering the flow necessary to sustain river life. Removing nonfunctional, outdated dams can bring a river back to its natural state and significantly increase biodiversity for the surrounding watershed.

A view from the site of the Heminway Pond Dam removal on July 19, 2018.

Currently, work is underway in Watertown, Connecticut to remove the Heminway Pond Dam, which restricts fish passage in Steele Brook, creates a pond with increased water temperatures and high bacterial levels due to high geese populations, and encourages deposition of iron precipitate in the stream channel just downstream of the dam.

Princeton Hydro designed the engineering plans, managed permitting and is now overseeing construction for the removal project. The removal of the Heminway Pond Dam is identified as an integral component in addressing water quality impairment between the dam and Echo Lake Road.

CT DEEP recently published this piece encapsulating the Heminway Pond Dam removal project:

REMOVAL OF HEMINWAY POND DAM ON STEELE BROOK IN WATERTOWN UNDERWAY

Upstream at rock-filled breach in Heminway Pond Dam and shallow, dewatered impoundment on Steele Brook in Watertown (7-18-18)

After almost 15 years of discussion and planning with the Town of Watertown and other partners, removal of Heminway Pond Dam on Steele Brook in Watertown finally got underway in early July.  Though no longer functional, the dam and pond were originally constructed to supply water for a former thread/string mill.  The Town acquired the dam and pond from the Siemon Company, the most recent owner, in 2007 with an eye towards removing the dam, restoring the river and converting the dewatered impoundment area into a passive recreation area, including an extension of the Steele Brook Greenway.  With these goals in mind, the Town approached CT DEEP for help with removal of the dam.

As it turns out, CT DEEP, has also had a strong interest in seeing this dam removed.  It is anticipated that dam removal will improve the hydrology in this section of Steele Brook and eliminate a water quality impairment which manifests itself during hot weather and low flow conditions, as an orange-colored plume of water (due to iron precipitate) immediately downstream of the dam that impacts aquatic life.  Dam removal would also benefit fisheries by restoring stream connectivity and habitat.

Working towards these mutual goals, CT DEEP was able to provide federal CWA 319 nonpoint source grant funding to USDA NRCS to develop a watershed-based plan for Steele Brook to address nonpoint source impairments that includes a dam removal feasibility analysis for Heminway Pond Dam.  Based on the recommendations in this plan, CT DEEP subsequently provided additional 319 grant funds to the Town of Watertown to hire a consultant to develop a dam removal design package, and assist with permitting and preparation.

With the Town of Watertown as a strong and vested partner, CT DEEP is now helping this project over the finish line by providing a combination of 319 and SEP funds to accomplish the actual dam removal and restoration of Steele Brook.  Dayton Construction Company is performing the construction and Princeton Hydro is the consultant overseeing the project on behalf of the Town.  The Northwest Conservation District is also assisting with the project.  It is anticipated that the majority of the work will be completed by this Fall.  U.S. EPA, ACOE and CT DEEP have all played active roles with regard to permitting the project.

 

A view of the first notch during the Heminway Pond Dam removal on July 17, 2018.

Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of dozens of small and large dams in the Northeast. Click here to read about a recent dam removal project the firm completed on the Moosup River. And, to learn more about our dam and barrier engineering services, visit: bit.ly/DamBarrier.

Creative, Timely Solutions Lead to Successful Dam Repair in Medford Lakes

By Kevin Yezdimer, P.E. and Jim Hunt, P.E.

Just 25 miles east of Philadelphia, on the edge of the New Jersey Pinelands region, sits a network of 22 lakes that serve a multitude of recreation purposes for the residents of Medford Lakes. Serving as the guardian to these natural beauties is the Medford Lakes Colony (MLC), a private homeowner association. Homeowners in this community contribute to a “Lake Restoration Fund,” managed by MLC, which is used to maintain the water control structures and monitor the water quality for the bodies of water within the community. This dedicated fund is often used for dredging of the lake beds; repairs and replacement of dams, spillways, and culverts; installation of aerators or fountains to promote long-term benefits to water quality; treatments for weeds and algae; and the maintenance of the coves and beaches.

In mid-April, a concerning blockage developed in Lake Wauwauskashe Dam’s spillway and water was backing up at the upstream outlet structure. The 30-inch wide corrugated metal pipe serves as the dam’s primary (and only) outlet under Wagush Trail, a neighborhood road connecting Lake Wauwauskashe and Lake Mushkodasa. During the attempt to clear the mass of accumulated woody-debris via vacuum truck extraction, a previous repair consisting of a 5’ segment of corrugated plastic pipe had been dislodged and expelled from the downstream end of the spillway. With a compromised dam and flooding in the forecast, MLC acted immediately to handle this emergency dam repair.

Primary Spillway Inlet
Before – Upper portion of the existing corrugated metal pipe was collapsed. After – Pipe was slip-lined and the annulary space was grouted.

 

Given Princeton Hydro’s long-term history of inspecting and maintaining dams and levees in Medford Lakes, MLC contracted our experts to assist. The next day, our team of geotechnical engineers were on-site to investigate the situation. To facilitate the inspection and minimize the stress/pressure on the dam, the upstream and downstream lakes were lowered via an NJDEP Fish and Wildlife Lake Lowering Permit. Additionally, a video inspection of the compromised culvert pipe was conducted. Our geotechnical team observed that the upstream portion of the pipe had collapsed and the structure was experiencing significant seepage (i.e. water flowing through undesirable paths through the dam with the potential for soil piping and stability failure).

Primary Spillway outlet
Before – The existing corrugated metal pipe had corroded and erosion had taken place around the outlet. After – Pipe has been slip-lined and outlet protection (riprap) was installed to stabilize the surrounding soil.

 

With the risk of potential dam failure, Princeton Hydro immediately kicked-off coordination with the NJDEP Bureau of Dam Safety, NJDEP Division of Land Use Regulation, the Pinelands Commission, and the Borough of Medford Lakes. Our licensed engineers promptly developed the repair concept and associated scope of work, detailing our proposed means and methods for the emergency repair.

“We take the potential risk of dam failure very seriously, as safety is one of our core values,” said Kevin Yezdimer, P.E. Director of Geosciences Engineering at Princeton Hydro. “Our geotechnical team prioritized the design, permitting, and implementation of this emergency repair to assure the safety of our client and the community.”

Injection grouting underway (Grout pressure is monitored during placement & the ground surface is monitored for signs of heave).

This included addressing the collapsed pipe; utilizing cementitious injection grouting and compaction grouting to eliminate seepage pathways and stabilize the earthen dam in-place; and provide spillway outfall protection. Through private solicitation, Princeton Hydro selected Compaction Grouting Services, Inc. as the specialty contractor to perform the repair.

A considerable volume of water was required to prepare the grout mixes, and no water sources were available adjacent to the project site. Seeking out solutions, MLC proposed the unique idea of using reclaimed wastewater from the local wastewater treatment plant. Our team confirmed that reuse of the reclaimed wastewater was indeed within the guidelines of the “Technical  Manual for Reclaimed Water for Beneficial Reuse,” and we successfully facilitated approval to use it with NJDEP Division of Water Quality.

Placement of cellular fill into the hollow concrete structure is underway. A lightweight foaming agent was added to the grout mix within the concrete truck. The lightweight grout was then pumped into the structure.

As the construction effort ramped-up, some complications arose. By design, this unique structure allows water flow over the dam’s weirs and drops 8 to 10 feet vertically before travelling under the roadway through the primary spillway. Above the primary spillway is a concrete structure that spans from the upstream lake to the downstream lake and immediately beneath the local roadway. It was discovered that this 50’ long, 6’ deep, concrete structure was hollow and served as a potential seepage pathway. Princeton Hydro proposed to fill-in the hollow structure with a lightweight cellular fill material in order to cut-off the potential seepage pathways, eliminate the 6’ deep hollow chamber beneath the roadway, and facilitate a long-term repair solution.

Implementation of this strategy was further complicated when a utility markout and a subsequent video inspection of the hollow structure confirmed that a gas line passed through the structure on the downstream side of the roadway. Princeton Hydro coordinated with South Jersey Gas to disconnect the gas line in order to minimize risk during construction and eliminate future complications. The neighborhoods on either side of the dam were fed redundantly, so their service was not interrupted during this process.

Overall, the emergency dam repair solution involved an in-situ soil stabilization of an earthen embankment dam via compaction/injection grouting, slip-lining the primary spillway, stabilization of the downstream outlet, and utilization of reclaimed wastewater as a water source for on-site grout batching. The following was completed by our team and contractors during the course of the emergency construction:

  • Slip-lining of the failed 30-inch pipe using a smooth, slightly smaller in diameter high density polyethylene pipe (HDPE) pipe inside of the existing pipe, providing an equal or greater hydraulic capacity as that existing;

  • Grouting of the annular space between the new and old pipes;

  • Non-woven geotextile fabric and riprap outfall protection were placed around the downstream outlet of the culvert pipe to provide scour protection;

  • Compaction and injection grouting was performed in multiple locations. The compaction grout utilized a “low-slump” mix while the injection grout utilized a much more mobile or fluid mix allowing for filling of existing seepage pathways or soil voids, and;

  • Approximately 44 cubic yards of lightweight cellular-grout backfill was utilized to fill in the hollow concrete structure beneath the roadway completing the emergency repair without the need for complete outlet structure or earthen dam reconstruction.

Lowering New Pipe Into Place

Creative, innovative solutions paired with timely coordination and expertise drove the success of the Lake Wauwauskashe Dam emergency repair.

Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of a dozens of small and large dams in the Northeast. To learn more about our dam and barrier engineering services, visit: bit.ly/DamBarrier.

Kevin M. Yezdimer, P.E., Princeton Hydro’s Geoscience Engineering Director, is a multidisciplinary professional civil engineer who holds degrees in both Geology and Civil Engineering, and has 11 years of progressive and varied work experience as both a design consultant and project owner with Geotechnical & Construction Engineering being his core area of expertise. He has significant experience performing soil and rock core sampling programs, infiltration testing, soils laboratory testing, foundation design (shallow and deep), preparation of construction recommendations,  and overseeing construction review activities (e.g., earthwork, foundations, concrete, masonry, structural steel, roadway, and utility construction).

 

Jim Hunt, P.E., joined Princeton Hydro in 2017 as a Geotechnical Engineer and provides a wide range of engineering services for the firm including: subsurface explorations, bearing capacity and settlement analyses, slope stability analysis, stability analysis of existing structures, preparation of technical deliverables, and cost estimating.

 

 

 

Lithuania Hosts First-ever Dam Removal Workshop Feat. Princeton Hydro Expert

Lithuania Hosts its First-Ever
Dam Removal Workshop

Princeton Hydro’s Laura Wildman Invited to Present

History was recently made in Lithuania with the occurrence of the first-ever dam removal workshop held in the country. Experts throughout the world convened at the Ministry of Environment in Vilnius, the capital of Lithuania, to lead discussions on a variety of topics related to dam removal and river rehabilitation.  They covered the current state of affairs regarding Lithuanian dams and showcased the Dam Removal Europe (DRE) initiative, a new effort aimed at restoring rivers in Europe.

The workshop was the brainchild of Lithuanian environmental activist Karolina Gurjazkaitė. She read about the DRE campaign and was so inspired by the initiative, she contacted DRE representatives about organizing the workshop. Her goals in organizing the first-ever dam removal workshop in Lithuania were to build awareness around the importance of river restoration, call attention to the many outdated, unmaintained, and unnecessary dams throughout Lithuania, and ultimately inspire positive changes in the way of dam removals and river rehabilitation.

“I am very excited, not only about the workshop, but also about the ‘side effects’…already created,” said Karolina. “People are gaining hopes and enthusiasm… This workshop may have really powerful outcomes!”

Karolina gathered a diverse group of workshop attendees, comprised of government officials (including the Vice-Minister of Environment of Lithuania), university professors (primarily specializing in dam safety and hydropower development), local environmental advocates and NGO volunteers, researchers, and students.

Presenters during the workshop included scientists, engineers, communication experts, planners, activists, and Princeton Hydro’s New England Regional Office Director and Fisheries Engineer Laura Wildman, P.E.

Presentations covered a wide variety of topics, including:

  • Policy and current situation in Europe: Pao Fernández Garrido of World Fish Migration Foundation, Spain presented on DRE findings related to policy and the current dam removal situation in Europe.

  • Research: Rachel Bowes from Karlstad University, Sweden spoke about current state of affairs with Swedish dam removal efforts and the research they are currently carrying out.

  • Book presentation: Herman Wanningen of World Fish Migration Foundation, Netherlands presented the new book, From Sea to Source 2.0, which is focused on tackling the challenges of restoring fish migration in rivers around the world and is available for free download.

  • Technical issues: Laura Wildman, PE, who has over 20 years of experience on dam removal, presented on the most important technical aspects when carrying out a barrier demolition.

On day two of the workshop, participants were invited to take part in field visits to five dam sites. Each of the five dams all presented their own unique challenges in terms of the ability to remove them. The site visits provided a deeper look into the challenges that will need to be addressed when forging ahead with a Lithuanian river restoration initiative.

The workshop proved to be instrumental in identifying key challenges and next steps in building a successful country-wide river rehabilitation initiative. One of the key takeaways from the workshop is the need for a more robust understanding of Lithuanian-specific rules and regulations that classify a dam removal project as either viable or not viable.

“Not only has there never been a dam removal workshop held in Lithuania, to date, a dam removal has never been completed in Lithuania, at least none that have been documented and none for environmental restoration reasons,” said Laura. “It’s clear that we still have a lot to explore and discover, but I am so thrilled to have been a part of this workshop. It was a very positive first step in the right direction, and I’m looking forward to watching and helping this initiative flourish.”

To learn more about Princeton Hydro’s dam removal and river restoration initiatives, go here.

 

Employee Spotlight: Meet Our New Team Members

Princeton Hydro is growing!

We’re excited to welcome seven 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
John Eichholz, Financial Strategist & Controller

John has a wealth of experience in financial analysis, strategic planning, business operations, and marketing strategy. As Controller and Financial Strategist for Princeton Hydro, he will oversee all finances and will work directly alongside our executive team to develop business strategies.

John has worked with an array of globally recognized companies, including Dun & Bradstreet, American Express, MasterCard, and Barclays. He specializes in financial forecasting, creating financial models and competitive intelligence reporting to enhance business understanding, developing strategic framework for how to manage initiatives across multiple constituents, and enhancing marketing performance through analysis. John has a BA in Political Science and an MBA in Marketing and Operations Management, both from Columbia University.

John lives in New Hope, PA, with his two children. When not attending swim meets and archery tournaments, John can be found cycling and attending music events throughout the Philadelphia area. Learn more.

Casey Clapsaddle, Hydrologist/Fluvial Geomorphologist

Casey recently joined our team as a full-time Hydrologist/Fluvial Geomorphologist after several years of outside consulting for Princeton Hydro through his company Rivers Unlimited. He has over twenty years of experience in hydrology, hydraulic studies, geomorphology, river restoration design, river stabilization design, habitat improvement and watershed management/restoration. Throughout  his career, he has continually developed bank stabilization, habitat improvement, and river restoration design techniques and construction approaches using natural materials, which provide projects with a more natural looking aesthetic. He strives to make all completed projects enjoyable places for relaxation, recreation and connection with the natural environment. Learn more.

Paul Cooper, Senior Ecologist

We’re excited to welcome Paul back to the Princeton Hydro team! He started in 2003 and took a brief hiatus to care for his daughter. With a focus on aquatic ecology, Paul will utilize his extensive experience to design and implement watershed-scale studies, develop management and restoration plans, and implement various water resource management strategies. Paul specializes in lake ecology with interests in fisheries, macroinvertebrates, aquatic macrophytes, plankton, and watershed and hydrology modeling. When he’s not working, Paul enjoys bird watching and fishing. Learn more.

Jake Dittes, EIT, Water Resources Engineer

Jake is a passionate engineer whose personal interests align well with his professional interests to restore habitat and natural functions of aquatic systems. As a Water Resources Engineer for Princeton Hydro, Jake assists in hydrologic and hydraulic modeling, project design, drafting and construction management on ecological restoration projects. Before joining the team, Jake worked in the energy sector to support energy efficiency by evaluating the efficiency portfolios of utility companies. Jake graduated as an Engineer from Harvey Mudd College, where he was highly involved in campus sustainability projects. Outside the office, Jake loves to be outdoors doing all types of fun activities. Learn more.

Angela Pelle, Water Resources Engineer

As a Water Resources Engineer, Angela has joined the team to work on a variety of restoration projects. Before coming to Princeton Hydro, she received her M.S. in Environmental Engineering at the University of Alabama, where she performed graduate research with the USDA. She studied land surface management on water budgets in agricultural regions of Tennessee, and quantitative impact of weather modification on streamflow in the North Platte River in Wyoming. Outside of the office, Angela enjoys Crossfit, playing tennis, and hiking with her dog, Albus. Learn more.

Casey Schrading, Staff Engineer

Casey joins the team as a staff engineer with a focus in water resources engineering. A graduate from Virginia Tech in 2018 with a degree in Biological Systems Engineering, Casey has experience in ecological restoration, flood management, water quality analysis, and best management practices. His experience also includes construction oversight for dam removal and restoration projects, and design, technical writing, and drafting for a variety of water resources engineering projects. In his free time, Casey enjoys hiking, skiing, and camping. Learn more.

Mike Tucci, Senior Project Manager, Engineering

Mike works as a Senior Project Manager and uses his strong background in water resource engineering and project management to contribute to the Engineering Practice area. He enjoys working in multi-discipline team environments and facilitating common sense thinking to solve complex problems. Prior to joining Princeton Hydro, Mike worked in a similar role as a consulting engineer and project manager supporting complex environmental and engineering projects in various business sectors. Mike lives in Bucks County, PA with his family. Away from the office when not exploring the outdoors on foot, bike or watercraft, he enjoys spending time in the kitchen. Learn more.

 

Conservation Spotlight: Dunes at Shoal Harbor Shoreline Protection

Hurricane Sandy was the largest storm to ever originate in the Atlantic ocean. It badly damaged several countries in the Caribbean, caused over $50 billion in damages along the Eastern Seaboard, and left dozens dead. While hurricanes are a natural part of our climate system, research shows that intense hurricane activity has been on the rise in the North Atlantic since the 1970s. This trend is likely to be exacerbated by sea level rise and growing populations along coastlines. Natural coastal habitats — like wetlands and dunes — have proven to shield people from storms and sea-level rise, and have protected coastal communities from hundreds of millions of dollars in damage.

The Dunes at Shoal Harbor, a residential community in Monmouth County, New Jersey, is situated adjacent to both the Raritan Bay and the New York City Ferry channel. The site, previously utilized for industrial purposes, consisted of a partially demolished docking/berthing facility. A significantly undersized 6” diameter, 8-foot long stone revetment was also constructed on the property.

During Hurricane Sandy, the revetment failed and the community was subjected to direct wave attack and flooding. Homes were damaged, beach access was impaired, and the existing site-wide stormwater management basin and outfall was completely destroyed.

Princeton Hydro performed a wave attack analysis commensurate with a category three hurricane event, and used that data to complete a site design for shoreline protection. Consistent with the analysis, the site design includes the installation of a 15-foot rock revetment (one foot above the 100-year floodplain elevation) constructed with four-foot diameter boulders. The project also consists of replacing a failed elevated timber walkway with a concrete slab-on-grade walkway, restoring portions of the existing bulkhead, clearing invasive plants, and the complete restoration of the failed stormwater basin and outlet.

A rendering of the “Dunes at Shoal Harbor” shoreline protection design by Princeton Hydro.

The plan incorporates natural barriers to reduce the impacts of storm surges and protect the coastal community, including planting stabilizing coastal vegetation to prevent erosion and installing fencing along the dune to facilitate natural dune growth.

These measures will discourage future erosion of the shoreline, protect the residential community from future wave attacks and flooding, and create a stable habitat for native and migratory species.  The project is currently in the permitting phase, and will move to construction when all permits are obtained from local, state, and federal agencies.

This project is an great example of Princeton Hydro’s ability to coordinate multi-disciplinary projects in-house. Our Water Resources Engineering, Geosciences Engineering, and Natural Resources teams have collaborated efficiently to analyze, design, and permit this shoreline protection project. For more information on our engineering services, go here.