UPDATE: NJ’s Dunes at Shoal Harbor Shoreline is Restored

The Dunes at Shoal Harbor, a coastal residential community in Monmouth County, New Jersey, is situated adjacent to both the Raritan Bay and the New York City Ferry channel.  In July 2018, Princeton Hydro was contracted to restore this coastal community that was severely impacted by Hurricane Sandy. Today, we are thrilled to report that the shoreline protection design plans have been fully constructed and the project is complete.

Rendering of the shoreline protection design
September 2020
A rendering of the shoreline protection design by Princeton Hydro. A snapshot of Princeton Hydro's completed work in September 2020.

In order to protect the coastal community from flooding, a revetment had been constructed on the property many years ago. The revetment, however, was significantly undersized and completely failed during Hurricane Sandy. 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.

July 2018
September 2020

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.

The site design and construction plans included:

  • The installation of a 15-foot rock revetment (one foot above the 100-year floodplain elevation) constructed with four-foot diameter boulders;

  • The replacement of 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; and

  • The development of 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 prevent shoreline erosion, protect the community from wave attacks and flooding, and create a stable habitat for native and migratory species.

During the final walkthrough earlier this month, the Princeton Hydro team captured drone footage of the completed project site. Click below to watch the video:

For more images and background information on this project, check out the following photo gallery and read our original blog post from July 2018:

Conservation Spotlight: Dunes at Shoal Harbor Shoreline Protection

For more information about Princeton Hydro’s engineering services, go here.

Client Spotlight: Musconetcong Watershed Association

In this photo, Princeton Hydro team member gathers data on the Hughesville Dam removal, using GPS to check the elevation of the constructed riffle on the beautiful Musconetcong River.

Welcome to the latest edition of our Client Spotlight Blog Series! Each spotlight provides an inside look at our collaboration, teamwork, and accomplishments with a specific client. We value our client relationships and pride ourselves on forming strong ties with organizations that share our values of creating a better future for people and our planet.

Meet the Musconetcong Watershed Association

The Musconetcong Watershed Association (MWA) is an independent, non-profit organization dedicated to protecting and improving the quality of the Musconetcong River and its watershed, including its natural and cultural resources. Members of the organization are part of a network of individuals, families, and companies that care about the Musconetcong River and its watershed, and are dedicated to improving the watershed resources through public education and awareness programs, river water quality monitoring, promotion of sustainable land management practices, and community involvement.

Princeton Hydro has been working with MWA in the areas of river restoration, dam removal, and engineering consulting since 2003. To develop this Client Spotlight, we collaborated with MWA’s Executive Director Cindy Joerger and Communications Coordinator Karen Doerfer:

Q: What makes MWA unique?

A: As a watershed association, we focus on a specific place. This includes the Musconetcong River, a National Wild and Scenic River, as well as the area’s cultural, historical, recreational, and natural resources. We take a watershed focus, seeking to monitor the river and upstream areas to ensure it maintains good water quality.

Q: What does MWA value?

A: MWA values community. Our membership is mostly grassroots, including residents, riverfront landowners, farmers, and local businesses. We value the long-term community of people who have helped form the organization, improve the river, and protect the scenic and historic resources that make our watershed unique.

Q: How long has MWA been working with Princeton Hydro?

Dam removal project partners and community members pose with Sally Jewell at the Hughesville Dam removal event on Sept. 8, 2016. Photo Credit: USFWS.

Project partners pose with Sally Jewell at the Hughesville Dam removal event in 2016. Photo Credit: USFWS.

A: Princeton Hydro has helped MWA with dam removal projects since the very first one, the Gruendyke Mill Dam, which was an obsolete dam on the border of Hackettstown and Mount Olive. Since then, Princeton Hydro has helped with four other dam removal projects and is currently assisting in the removal and restoration of the Beatty’s Mill Dam in Hackettstown, providing engineering plans and project management support.

The dam removals in the lower Musconetcong River have created a free-flowing passage to the Delaware River, and the removal of the Hughesville Dam welcomed the return of American shad less than a year after its removal.

Q: What types of services have Princeton Hydro provided to your organization?

A: Princeton Hydro has provided MWA with dam removal services on the Musconetcong River, most notably, the removal of Hughesville Dam, which brought Secretary of the Interior, Sally Jewell, out for its notching. Princeton Hydro has also helped us with the engineering and design for the Musconetcong Island Park Project, which involves the demolition of a building in a Historic District and the replacement of new, safer stairs.

We value Princeton Hydro’s expertise in environmental permitting, hydrology, and fisheries, as we have utilized this expertise to review development proposals and conduct fish surveys.

Q: Do you have a favorite or most memorable project we’ve worked on together?

A: The Hughesville Dam removal saw many successes and a few challenges we had to overcome as a team. After the initial removal and restoration, we worked together on another streambank restoration project to further stabilize the streambank near the dam removal site. This dam removal restored over 5 miles of free-flowing river to the Delaware River and will help lay the groundwork for the Warren Glen Dam removal, which is the largest dam on the Musconetcong River.

Hughesville Dam Removal on the Musconetcong River

Bringing fish back to native spawning grounds always makes us feel good! After Superstorm Sandy, millions of dollars were spent to remove dams from coastal waters and since then, species like American Shad, Eastern Brook Trout, and River Herring are making a comeback in our fresh water bodies. We had the pleasure of working on two of the projects mentioned: the removal of the Hughesville Dam on the Musconetcong River (video below) and Wreck Pond in Spring Lake, NJ. Full story: http://bit.ly/2SFtaEb

Posted by Princeton Hydro on Monday, December 10, 2018

 

Q: What are some exciting things your organization is working on right now?

Photo from Princeton Hydro led volunteer clean-up effort on the Musconetcong River in 2018. The team picked-up garbage along the road and riverbank, and pulled trash from the riverbed.

Photo from a Princeton Hydro-led volunteer cleanup effort on the Musconetcong River in 2018.

A: MWA is still working to restore the Asbury Mill, which we plan to use as an educational and eco-tourism hub for the community, as well as a much-needed office space for our growing staff.

We’ve also received some exciting new grants that will help us continue to involve the community in efforts to protect and improve water quality. Our “Push Back the Lawn” campaign will allow us to reach out to small landowners and educate them on the importance of riparian buffers.

This year has also brought some challenges for our organization, but we are excited to be picking up our River Cleanup again this fall. Normally, we conduct a watershed-wide cleanup in April, but due to COVID-19, we had to push it back. However, families and small groups are glad to be able to get out and give back by picking up trash that has collected with increasing staycations and small trips.

Q: What drives you to want to go to work every day?

A: Working for such a small organization, it is easier and more gratifying to see the impact it’s making. Our staff gets to see a lot of projects from start to finish, so it’s rewarding to be able to have your stamp on something you watched grow from its inception to conclusion.

Q: How can Princeton Hydro support you/your organization in the future?

A: In the upper watershed, we are hoping that Princeton Hydro, in concert with others, can continue to help guide improvements to the water quality of Lake Hopatcong. The lake acts as our headwaters and is the largest in New Jersey. Last year, it suffered a serious issue with Harmful Algal Blooms.

We are also looking forward to the Beatty’s Mill Dam removal project, where we will remove a remnant dam and reduce streambank erosion. We hope this will roll into another similar project at Newburgh, which should improve water quality and fish habitat and decrease flooding severity in the Hackettstown area.

Delaware River Watershed Forum participants tour dam removal sites along the Musconetcong River.

Delaware River Watershed Forum participants tour dam removal sites along the Musconetcong River in 2019.

Click below to read the previous edition of our Client Spotlight blog series, which features the Lake Hopatcong Foundation:

Client Spotlight: Lake Hopatcong Foundation

Employee Spotlight: Meet Our Two New Team Members

We’re excited to announce the expansion of our growing business with the addition of two new team members who have experience and qualifications in water resource management.

Meet the new team members:

Robert costello, water resource engineer

Robert is a passionately curious water resources engineer who is determined to use his knowledge and experience to provide the best possible outcomes for our clients in every one of his projects. Robert received his degree from the University of Delaware, with a major in Environmental Engineering and a Minor in Civil Engineering. While in school, he was involved heavily in the research conducted at the University’s Water Science and Policy department. After schooling was finished, he used his degree to work on various engineering projects including subsurface geotechnical investigations, hydrologic and hydraulic modeling of water conveyance systems, stormwater BMP design, as well as the complete design, modeling, and supervision of Green Infrastructure Systems.

Outside of work, Robert is an avid outdoor enthusiast. He enjoys kayaking, hiking, and skiing in the Adirondacks during the winter.

Mark Herrmann, PE, CFM, Senior Project Manager, Green Infrastructure & Stormwater Management

Mark is a Civil Engineer and Certified Floodplain Manager with extensive experience in both the public and private sectors. His areas of expertise include stormwater management, hydrologic and hydraulic studies, sustainable design, utility design, and land development. Mark has served as a lead engineer, project manager, and construction manager for a variety of large-scale and small-scale residential land development projects, transportation improvement projects, and utility infrastructure projects. He is passionate about protecting our water supply and our environment and enjoys working on complex, challenging projects that benefit our natural resources.

With four kids at home, Mark does not have much free time. If he does catch a break from the action, you can find him with his head in a book, sitting behind a chessboard, or gazing at the stars and planets through his telescope.

The Ecogeomorphic Evolution of Louisana’s Wax Lake Delta

By Brittany Smith, Environmental Scientist at Princeton Hydro 

As a graduate student in the geology program at the University of Texas at Austin, I worked on a study that used remote sensing to explore links between coastal geomorphology and ecology at the Wax Lake Delta in Louisiana. In this blog, I provide a snapshot of my research, which was recently published in the journal Remote Sensing.

 

What is the Wax Lake Delta?

The Wax Lake Delta is a small, young river delta in Louisiana that began growing in the 1940s after the construction of the Wax Lake Outlet. In 1941 the U.S. Army Corps of Engineers dug the Wax Lake Outlet from the Atchafalaya River – it extended out to the coastline and was designed to reduce the severity of floods in nearby Morgan City.

Image by NASA/Jesse Allen: While the Mississippi River Delta has been washing into the Gulf of Mexico and receding just to the west the Wax Lake and Atchafalaya River deltas (pictured above) are growing. Satellite imagery shows how the deltas have grown between 1984 (left) and 2014 (right).

This outlet provided a constant flow of water to be diverted from the river before reaching the banks of Morgan City, which had experienced several devastating floods. Approximately 40 percent of the Atchafalaya’s discharge gets channeled through the Wax Lake Outlet, which has the capacity to carry a maximum of 440,000 cubic feet per second.

Following the creation of the Wax Lake Outlet, the turbulent flow of water began to carry sediment down the outlet, which deposited at the mouth of the outlet and, over time, caused an underwater delta to grow. In just over 40 years, the Wax Lake Delta grew from nothing to an area twice the size of Manhattan. Research shows that it receives 34 million tons of sediment per year. Today, it spans roughly 7 miles out into the Gulf of Mexico and provides valuable habitat for a variety of animals.

 

The Why Behind the Research

Many coastal areas have been retreating or drowning as a result of subsidence and decreased sediment availability due to upstream dams and levees. According to the Population Reference Bureau, “Today, approximately 3 billion people — about half of the world’s population — live within 200 kilometers of a coastline. By 2025, that figure is likely to double.”

This population is increasingly vulnerable to flooding and erosion due to sea level rise and storms, especially in coastal Louisiana, where land loss is prevalent due to subsidence and decreased sediment supply.

The Wax Lake Delta is one of the few places in coastal Louisiana that is building rather than losing land, so is seen as an example of processes that could be applied elsewhere on the Gulf Coast to mitigate subsidence and restore coastal wetlands. Additionally, it is an ideal study site because it is relatively small, young enough that it has a good historic record, and has been largely unaltered by human activities.

This image depicts the study area: (a) The Wax Lake Delta (WLD, red square) is located at the terminus of the Wax Lake Outlet (blue line), which diverts water from the Atchafalaya River (purple line) in the U.S. state of Louisiana. The Atchafalaya is a distributary channel for the Mississippi (green line) and Red (red line) Rivers. (b) Image of WLD from 28-Sep-2010 by Landsat [88], for water level y = 0.35 m (NAVD88) at Camp Island gage (yellow dot) [93]. (c) Image of WLD from 24-Apr-2011 by Landsat [88], for water level y = 0.67 m (NAVD88) at Camp Island gage. WLD Pintail Island test case area outlined in white.

 

The Research in a Nutshell

Elevation is a very important variable in coastal ecosystems, as it controls how frequently a site is flooded. This in turn controls how frequently sediment can be delivered or removed from the site, and also what type of vegetation will grow there.

To understand how the Wax Lake Delta is growing, it would be ideal to have an understanding of how the topography has changed over time. Unfortunately, very little elevation data was available for the Wax Lake Delta, so I had to develop an indirect way of getting this information.

Photo Credit: Field and StreamWhat I did have available was a significant amount of Landsat satellite imagery. This was useful to me for two reasons: the delta is extremely flat and low-lying (less than 3 feet above sea level), and the tidal cycle typically fluctuates between 0-3 feet above mean sea level. This means that since each satellite image is taken at a different water level, different parts of the delta are exposed above the water in each picture. Taken together as a group over time, we can start to get a sense of which areas are higher and more likely to be exposed, and which areas are more likely to be flooded, and therefore at a lower elevation.

To do this in a quantitative way, I took all the images taken over a three year period and converted them to binary images, where land was classified as 1, and water classified as 0. I then added the images together, to create a composite image where pixels with higher values corresponded to areas that were exposed more frequently, and pixels with lower values were more frequently flooded.

Using water level data from a USGS gauge station that was installed at the delta in late 2008, I was able to develop a probability distribution of water levels. Taking these together – a probability map of flooding frequency and a probability distribution of water level elevations – I was able to create topographic maps based on the Landsat satellite imagery.

By performing this method over a number of years, patterns emerge about how the delta is evolving over time. The island changes from a relatively amorphous, unorganized shape to a defined outer levee and inner island platform.

Photo Credit: The National Wildlife FederationA deeper knowledge of the delta topography, allows us to look at connections to the delta ecology. We know that elevation controls hydrology and therefore plant growth, but we have also seen situations where plants can in-turn affect elevation by contributing organic matter to the soil, preventing erosion due to the root mat, or trapping sediment with their stems when sediment-laden water flows through.

In the case of salt marshes, previous studies have shown that if there is a feedback between the two, it occurs because a) plants tend to be most productive at a specific elevation and b) plants are in some way contributing to sediment accumulation relative to their productivity.

Photo Credit: USGSFor example, if a plant grows best at an elevation of two feet, it grows really densely at two feet, contributes more organic matter to the soil, bigger roots grow that help increase cohesion and reduce erosion, and the stems are denser and trap more sediment when the area is flooded. These all help increase the elevation of the marsh over time. However, if the elevation starts to get too high, the plant grows less densely, contributes less to the marsh surface, and the elevation will drop back down until the plant is happy again. Over time, the surface of the marsh will start to organize around these ideal elevations, creating a terraced effect with platforms corresponding to different plant types that do particularly well at that elevation.

When we look at how a transect down the center of the delta island has changed over time, we see that it goes from a relatively smooth, straight line, to a stepped system comparable to the models from other studies. When we compare the elevations of these platforms to the vegetation communities at the delta, we find that they correspond positively to high-marsh and low-marsh plants. This suggests that there is feedback occurring between plants and sediment accumulation at the delta.

 

In Conclusion

This research a) developed a new approach for investigating changes in coastal topography using satellite imagery, and b) confirmed that there is likely to be feedbacks between sediment deposition, marsh elevation, and vegetation growth. These feedbacks should be considered in any coastal wetland restoration and land building efforts.

 

Brittany Smith is an Environmental Scientist with an extensive background in hydrology and ecology. At Princeton Hydro, she has been involved in a wide variety of projects including stream assessments, wetland water budget modeling, soil field assessments, GIS analysis, permitting, and aquatic ecology. She holds a Master of Science in Geology with an emphasis in hydrology and geomorphology from the University of Texas at Austin, and a Bachelor of Science in Plant Biology from the University of California at Davis. Brittany has strong skills in data analysis and management, as well as experience in a broad range of field and laboratory techniques.

 

Community Science on the Schuylkill River

The nonprofit Schuylkill River Greenways, in partnership with Berks Nature, Bartram’s Garden, The Schuylkill Center for Environmental Education, Stroud Water Research Center, and Princeton Hydro, is kicking off a Water Quality Monitoring Project for the Schuylkill River on World Habitat Day, Monday, October 5, 2020. This project, focused on the main stem of the river from Berks Nature in Reading to Bartram’s Garden in southwest Philadelphia, is aimed to document the current ecological status and health of the river and seeks to engage and educate a diverse set of river users and residents.

“An important aspect of our mission is to connect communities to the Schuylkill River through recreational and educational activities,” said Tim Fenchel, Deputy Director of Schuylkill River Greenways. “To fully achieve the river’s potential, we must help the public understand the current health status and what they can do to continue to improve its quality for this generation and generations to come.”

In order to monitor the presence and/or distribution of litter along the Schuylkill River, the team is launching a campaign to recruit “Community Scientists” to conduct 5-minute Visual Monitoring Assessments. Using their mobile device, these volunteers can simply record the trash accumulation or dumping points along a 100-foot section of the Schuylkill River via a user-friendly form accessed via a cell phone: bit.ly/litterform.

“Trash is important to address when talking about the health of a waterway because it’s often the most visually obvious form of pollution. Bacterial and chemical pollution are generally less directly observable, but when we see trash, it instantly informs our impression of a body of water,” said Chloe Wang, River Programs Coordinator at Bartram’s Garden. “And, it can point to larger problems. For example, near Bartram’s Garden, a lot of trash washes into the river from combined sewer overflows, which also introduce harmful bacteria into the water. It will be interesting to see how the presence of trash differs along various stretches of the Schuylkill.”

The Community Scientist visual assessments require no formal training and are meant to be a simple effort that any resident can complete. We’ve developed an assessment survey, which can be accessed and submitted via a smartphone or tablet by opening the link in the phone/tablet’s browser.

“This is an opportunity for anyone with an interest in the Schuylkill River to spend time on the river and provide valuable feedback on the conditions of the river,” said David Bressler, Project Facilitator at Stroud Water Research Center. “Schuylkill River Greenways and its partners in this project are looking for motivated and dependable individuals to help them learn about the Schuylkill River and move in positive directions toward making the river more accessible to the community. Support from volunteers is very important and is greatly appreciated.”

The goal is to document critical areas of trash accumulation or dumping points in order to guide management efforts to better deal with this pollution. In addition to the multiple-choice questions to rank trash levels and quantities, this platform asks volunteers to submit a photo of the area and collects the GPS location. By utilizing this user-friendly platform, the data collected under this effort will be summarized and visualized by the project team.

“This project is an important study that we can use to connect people back to the river and show that the Schuylkill River is a place to be enjoyed by the entire community surrounding it and beyond,” said Michael Griffith, Education & Watershed Specialist at Berks Nature.

In 1985 the United Nations designated the first Monday of October every year as World Habitat Day. The idea is to reflect on the state of our towns and cities and the basic right of all to adequate shelter and to remind the world of its collective responsibility for the future of the human habitat. By understanding and improving water quality in the Schuylkill River, we are creating a place that enables community members to access public green and open spaces. This effort also supports UN Sustainable Development Goal 11, which aims for resilient, inclusive, safe, diverse cities by 2030.

In addition to the Community Scientist visual assessments, the stakeholder team is conducting water quality sampling and monitoring over the next year at four locations along the main stem of the Schuylkill River. This scientific documentation of critical water quality parameters will be performed by the stakeholder group’s employees and long term volunteers, who are trained in data collection and scientific methods. We will collect data on bacterial concentrations in the river using a combination of 3-M Petrifilm kits and laboratory-based analytical measures. In addition, in-situ temperature, oxygen, pH, and turbidity data will be collected utilizing Mayfly dataloggers.

“Our research shows that residents care about the river, but are not confident whether it is clean or safe to use for recreational activity. So we’ve designed a volunteer survey and scientific water quality assessment to document the ecological health of the Schuylkill River,” said Michael Hartshorne, Aquatic Resources Project Manager at Princeton Hydro. “By studying bacterial inputs and identifying hotspots for trash, we can communicate the status of the river, provide recommendations on areas of improvement, and ultimately, change the current public perception of the river.”

For the water quality monitoring, Princeton Hydro scientists will provide training to the partner nonprofit organizations’ staff and review the methods and protocols to assure the highest level of quality. This long-term data collection effort is slated to begin this month and continue for approximately one year. The results of this assessment will allow us to determine potential hotspots related to nutrient and bacteria inputs and to understand the overall ecological health of the Schuylkill River.

Overall, through this effort, the stakeholder team hopes to connect residents and communities with the Schuylkill River and to encourage engagement with this special resource.