About phadmin

Princeton Hydro was formed in 1998 with the specific mission of providing integrated ecological and engineering consulting services. Offering expertise in aquatic and terrestrial ecology, water resources engineering, and geotechnical investigations, our staff provides a full suite of environmental services. Our team has the skill sets necessary to conduct highly comprehensive assessments; develop and design appropriate, sustainable solutions; and successfully bring those solutions to fruition. As such, our ecological investigations are backed by detailed engineering analyses, and our engineering solutions fully account for the ecological and environmental attributes and features of the project site. We take great pride in our reputation with both clients and regulators for producing high-quality projects over a wide variety of service areas; doing so requires a highly skilled team committed to keeping abreast with current research, technology and regulations. Our capabilities are reflected in our award-winning projects that consistently produce real-world, cost-effective solutions for even the most complex environmental problems.

Five Ways to Participate in Lakes Appreciation Month

#LakesAppreciation Month is a great time of year to enjoy your community lakes and help protect them. 

Lakes Appreciation Month was started by North American Lake Management Society (NALMS) to help bring attention to the countless benefits that lakes provide, to raise awareness of the many challenges facing our waterways, and encourage people to get involved in protecting these precious resources.  Unfortunately, the natural beauties that provide clean drinking water and wildlife habitat are at risk. Chemical pollutants, hydrocarbons, stormwater runoff, invasive aquatic species, and climate change are just a few of the the serious threats facing freshwater habitats.  So what can you do to to help?

We’ve put together five tips to help you celebrate Lakes Appreciation Month and get involved in protecting your favorite lakes:

1. Join the “Secchi Dip-In” contest: The “Secchi Dip-In” is an annual citizen science event where lake-goers and associations across North America use a simple Secchi disk to monitor the transparency or turbidity of their local waterway.  This year, Princeton Hydro is offering “Secchi Dip-In” participants a chance to win a $100 Amazon gift card and a one-year membership to NALMSEntry details here.

2. Organize a cleanup event: You can easily organize a lake clean-up in your community! Volunteer cleanups are a great way to get neighbors together around a good cause, raise awareness about the importance of protecting water quality, and make a positive impact on your community waterways. Organizing a volunteer event is a lot easier than you may think. Check out these tips for how to get started.

3. Get involved with your local lake: You can help support your favorite lake by joining a lake or watershed association. As an organized, collective group, lake associations work toward identifying and implementing strategies to protect water quality and ecological integrity. Lake associations monitor the condition of the lake, develop lake management plans, provide education about how to protect the lake, work with the government entities to improve fish habitat, and much more.

4. Monitor and report algae blooms: With the BloomWatch App, you can help the U.S. Environmental Protection Agency understand where and when potential harmful algae blooms (HABs) occur. HABs have the potential to produce toxins that can have serious negative impacts on the health of humans, pets, and our ecosystems. Learn more and download the app.

5. Get outside and enjoy: Whether you enjoy swimming, relaxing on the shoreline, canoeing, or fishing, there are countless ways you can get outside and enjoy your community lakes. Encourage others to appreciate their local waterbodies by taking photos of your lake adventures and sharing them on social media using the hashtag: #LakesAppreciation.

 

Go here to learn more about NALMS and get more ideas on how to celebrate your local lakes. If you’re interested in learning more about Princeton Hydro’s broad range of award-winning lake and pond management services, please contact us. 

Celebrating the Columbia Dam Removal

A view of the Columbia Dam at the beginning of the removal process.

On a bright, sunny day in Warren County, Princeton Hydro celebrated the Columbia Dam Removal Project with New Jersey Department of Environmental Protection (NJDEP) Commissioner Catherine McCabe, The New Jersey Nature Conservancy (event organizer), American Rivers, U.S. Fish and Wildlife Service (USFWS), NJDEP Division of Fish and Wildlife Service, RiverLogic Solutions, and SumCo Eco-Contracting.

Beth Styler-Barry, River Restoration Manager, New Jersey Nature Conservancy

Overlooking the soon-to-be removed, century-old, hydroelectric Columbia Dam, key stakeholders, including Princeton Hydro’s President Geoffrey Goll, P.E. and New Jersey Nature Conservancy’s Director Barbara Brummer, remarked on the success of the project, collaborative team efforts, and future benefits to the Paulins Kill habitat.

NJ Nature Conservancy’s River Restoration Manager, Beth Styler-Barry thanked project funders including NJDEP’s Office of Natural Resource Restoration, USFWS’s Fish Passage Program, National Fish and Wildlife Foundation’s Bring Back The Natives program, Natural Resources Conservation Service’s Regional Conservation Partnership Program, New Jersey Corporate Wetlands Restoration Partnership, Leavens Foundation, Tom’s of Maine, and Nature Conservancy members and donors.

“We made a commitment early-on to a 10-year monitoring and measurement plan. The removal of Columbia Dam is an opportunity to gain new knowledge and generate data that builds the case for this type of restoration. We’ll be looking at everything from mussels to temperature to geomorphological changes to increasing our targeted efficiencies. We’re also going to use images taken from repeated drone flyovers to look closely at changes in topography,” said Styler-Barry.

NJDEP Commissioner Catherine McCabe with NJ Division of Fish & Wildlife and NJDEP officials.

NJDEP Commissioner Catherine McCabe added, “The Columbia Dam is ranked in the top 5% of the nearly 14,000 dams that were assessed for priority. It will give us one of the most bangs for our buck in terms of fish and native species that we’ll be able to bring back up here.” She added, “This is exactly what Natural Resources Damages funds should be used for, and we are thrilled to see it come to fruition.”

Geoffrey Goll, P.E., President, Princeton Hydro

Back in the day, this dam structure was a marvel of engineering. Because concrete was very expensive during the time of construction, a patented, innovative “ransom hollow” design was used, which means it has a hollow center with series of doorways underneath the dam, explained Geoffrey Goll, P.E., President of Princeton Hydro. However, sustainability and climate change are very important issues today and must be taken into consideration for the life-cycle of a dam.

“Removal is a logical step in the history of this dam. Dam removals are the most impactful restorations. They provide the most ecological uplift and improvement for rivers,” Goll stated.

For Princeton Hydro, this project involved every discipline we have in the firm: civil engineering, fishery biology, wetland science, hydraulics, geotechnical engineering, and regulatory work. We were contracted by American Rivers to investigate, design, and permit for the removal of this dam for the New Jersey Nature Conservancy. Our team of engineers and ecologists studied the feasibility of removal by collecting sediment samples, performed bioassay tests, and conducted a hydraulic analysis of upstream and downstream conditions. Currently, we are providing construction administration services during the removal process. This project is a great example of our ability to complete multi-disciplinary projects in-house.

Project partners ready for the first hammer with the celebratory dynamite and sledge hammers.

At the end of the press conference, project partners celebrated the anticipation of the “first hammer” in the near future with an imitation dynamite siren and plastic sledge hammers. It was truly a keystone moment for everyone involved in this project.

The remnant dam downstream has already been removed and the main dam is due to be removed very soon. Check out our previous story with a series of photos documenting this first-step in the overall dam removal process: bit.ly/ColumbiaDamRemoval. Stay tuned for photos during the main dam removal process too.

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 fish passage and dam removal engineering services, visitbit.ly/DamBarrier.

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.

How’s the Fishing? Tips for Managing Your Lake’s Fishery

The fishery of a lake is an intrinsic, incredibly dynamic element of a lake system, and managing a lake’s fishery can be a very complex endeavor. There is actually a lot more to it than simply stocking game fish. Although there is no “one way” in fisheries management, there are key guidelines that can be followed to maximize the recreational potential of your lake’s fishery and increase the success of your fishery management and stocking efforts. Over the past two decades, Princeton Hydro has been working with lake, pond, and reservoir managers to help them to align water quality, fishery, and ecological goals.

Princeton Hydro’s Founder, Dr. Steve Souza, recently gave a presentation on fisheries management at the Spring Meeting of the New Jersey Coalition of Lake Associations (NJCOLA). We’ve compiled a few essential elements from his presentation and have made the complete presentation available for free download.

Let’s dive in!

Benefits of a Healthy Fishery

Recreational fishing is an outdoor activity that can be enjoyed by people of all ages. When children are introduced to fishing, it helps cultivate a connection to the environment, thereby promoting outdoor activity and environmental stewardship among today’s youth.

Anglers have always served as important advocates for the conservation of natural resources. The sale of fishing licenses financially supports wildlife habitat conservation and enhancement as well as the protection and improvement of water quality. This increases the ecological services and functions of lakes and adds to their societal and recreational benefits.

A healthy fishery can have significant positive impacts on water quality. In a balanced, healthy fishery the ratio of forage and game fish affects the entire food web, helping to maintain the proper balance of zooplankton and phytoplankton. The “top down” ecological control associated with a balanced fishery minimizes algae blooms, sustains good water clarity and stable water quality. However, when the fishery is out of balance, the water quality and overall ecological health of the lake often suffers.

Before You Stock, Know Your Lake and Start with a Baseline

Before you do any fish stocking, it’s best to conduct a fishery survey. A fishery survey provides the vital data needed to design a stocking and management plan.

A balanced lake fishery is dependent on good water quality, ample habitat, and the correct ratio of predator and prey fish species. A properly designed and implemented fishery survey generates the data needed to quantify the overall composition of the existing fish community (predator vs. prey), the make-up of the forage (food) base, and the density and robustness of the lake’s top piscivores (prized game fish).

The resulting data helps identify if your fishery is balanced, which fish to stock, and how many of each species to introduce. It will also provide the benchmarks needed to solidify your management goals and, later on, help determine if the goals are being met. To stay on track, we recommend that a comprehensive fishery survey be conducted once every three years. Be sure to use the correct types and combination of “active” and “passive” sampling gear and thoroughly sample both the open water and nearshore areas of the lake.

The survey should include the collection and analysis of water quality data, and the mapping of available habitat. Water column water quality “profiles” provide vital information pertaining to the lake’s thermal and dissolved oxygen properties; key factors for a healthy, vibrant fishery. Here are some basic water quality guidelines:

  • Dissolved oxygen: ≥ 4 mg/L with 6-7 mg/L being ideal
  • For warm water fishery: Uniform temperatures at all depth (minimal or no thermal stratification)
  • For cold water fishery: Deep water temperature of 15 C, and dissolved oxygen ≥ 5 mg/L
  • pH: 6 to 8
  • Clarity: ≥ 3 feet (1 meter) Secchi disc transparency
  • Total Phosphorus: < 0.05 mg/L
  • Chlorophyll a: < 20 µg/L

Water quality sampling should also include an assessment of the lake’s zooplankton and phytoplankton communities, the base of your lake’s food web.

Floating Wetland Island

During the survey, take the time to quantify and map the distribution of existing forage, spawning, and refuge habitat. Lack of adequate habitat can significantly impede the fishery’s sustainability. This begins with the bathymetric mapping of the lake, which is basically an underwater survey of the bottom of the lake. This mapping shows where and how much shallow water versus open water habitat exists.  It can also help identify the location and distribution of important habitat types, such as shoals, rock piles, sandy open areas and natural structures (tree falls and snags). The data also helps determine where to create and introduce habitat, which can be in the form of brush piles, floating wetland islands, and other types of features that increase the spawning, recruitment, and foraging success of the fishery.

Stocking Your Lake

Once the fishery survey is completed, habitat is mapped and water quality analyzed, stocking can begin. In order to determine the specific stocking levels and rates that are right for your waterbody, here are some factors to consider:

  • Ensure your stocking efforts create or augment the correct ratio of predator (game) and prey (forage) fish.

  • Stock cautiously, focusing on a simple composition of predator and prey species. For most warm water lakes, largemouth bass should serve as the top predator and fathead minnow should be the primary prey.

  • Avoid problem fish, such as golden shiner, alewife and brown/black bullhead. Although these fish are often promoted as suitable forage species, they can be easily get overstocked and cause major disruptions of the fishery and to the degradation of water quality.

Go here for a more in-depth look at how to properly stock your fishery.

In Summary

A healthy sustainable fishery isn’t only a function of the types and amounts of fish stocked in a lake; it is directly a function of water quality, the availability and quality of spawning, foraging and refuge habitat, the ratio of forage to predator fish, and the overall composition and balance of the food web.

Begin with a fishery survey; the resulting data enables a correctly planned and implemented stocking program. Conduct routine surveys to assess the status of the fishery and the success of the program. Also, annual water quality testing provides the information needed to make wise pro-active fishery management decisions. It will also provide insights into the lake’s environmental conditions to ensure they are supportive of a healthy, productive and sustainable recreational fishery.

Learn More

If you’re interested in learning more about Princeton Hydro’s fisheries management or lake management services, please contact us.

Click here to download a full copy of Dr. Souza’s presentation, titled “How’s the Fishing? Maximizing the Recreational Potential of Your Lake’s Fishery,” which he recently presented at the NJCOLA Spring Meeting. The presentation provides an in-depth set of guidelines for fishery management, covering topics like data collection methods, habitat creation and enhancement, maximizing habitat quality, and details on various stocking species to consider for your lake.

NJCOLA unites lake communities throughout New Jersey through education and by formulating legislation favorable to the protection and enhancement of the State’s lake resources. NJCOLA meetings, held on a regular basis in the spring and fall, educate members on various topics and issues affecting lake communities ranging from legal to environmental.

The Spring NJCOLA meeting was well attended with over 60 participants representing lakes throughout New Jersey, including a number of lakes that are managed by Princeton Hydro – Lake Mohawk, Lake Hopatcong, White Meadow Lake, Lake Swanannona, Kehmah Lake, Culver Lake and Swartswood Lake.

To learn more about Princeton Hydro’s Pond and Lake services, including water quality sampling, bathymetric surveying, floating wetland islands, and fisheries, visit: http://bit.ly/pondlake 

 

CONTEST ALERT: Celebrate #LakesAppreciation Month and Win $100

How healthy is your lake? July is Lakes Appreciation Month and we’re celebrating with a contest! To raise awareness about water quality, we’re encouraging people who enjoy lakes to participate in a “Secchi Dip-In” for a chance to win a $100 Amazon gift card and a one-year membership to the North American Lake Management Association (NALMS).

What is the “Secchi Dip-In”?

The “Secchi Dip-In” is an annual citizen science event created by NALMS in 1994. It was developed in order to involve lake-goers and associations across North America in using a simple Secchi disk to monitor the transparency or turbidity of their local waterway.

This data collected is evaluated on a regional scale by NALMS and helps lake managers further understand the water quality of lakes in their region. Since 1994, more than 10,000 trained volunteers have generated 42,000 transparency records, giving a glimpse of lake water transparency at sites across North America and the world, according to NALMS.

How do I collect a Secchi sample?
  1. What is a Secchi disk and what data is collected with it?
    The typical Secchi disk used in lakes is an 8-inch disk with alternating black and white quadrants. It’s lowered into the water until the observer can no longer see it. The depth of disappearance, called the Secchi depth, is a measure of the transparency of the water. The disk is named in honor of Father Pietro Angelo Secchi, astronomer and scientific advisor to the Pope, who tested this new instrument in the Mediterranean Sea on April 20, 1865.
  2. Where can I get a Secchi disk?
    Secchi disks are a low-cost investment and a great tool to have for measuring water quality. You can purchase a Secchi disk on Amazon or other online marketplaces for $20-$30. Alternatively, you can always ask a friend or your local lake manager to borrow one. Some people even make their own!
  3. How do I take a measurement? How many times do I do it?
    A measurement is taken by lowering the disk on the sunny side of the boat. To eliminate sun glare, an underwater viewer (viewscope) can also be used if so desired. Allow sufficient time (preferably 2 minutes) when looking at the disk near its vanishing point for the eyes to adapt completely to the prevailing luminance level. Record the depth at which the disk disappears. Slowly raise the disk and record the depth of reappearance. The “Secchi depth” is the average depth of disappearance and reappearance. For further accuracy, several people can each record several Secchi depths. Then, all of the depths can be averaged into one single reading. Please note: the water depth should be at least 50% greater than the Secchi depth so that the disk is viewed against the water background, not bottom-reflected light.
  4. What’s the best time of day to collect a sample?  
    The best time of day to collect a sample is when the sun is at its highest point in the sky, generally around midday. Most volunteers generally collect data between the hours of 10:00 AM and 2:00 PM.
  5. What do the results mean?
    The Secchi disk measures transparency, which serves as an indicator of changing water quality. Transparency decreases as the amount of particles in the water— such as algae and sediment—increases.

Check out this “How to Secchi Dip” video created by Princeton Hydro Senior Limnologist Michael Hartshorne:

How to Enter the Contest:

One lucky winner will be randomly selected on August 1, 2018.  The selected winner will receive a $100 gift card to Amazon and a one-year membership to NALMS. We’ll reach out to you via social media to collect your email and address for prize distribution. If the winner does not respond within 5 working days with the appropriate information, we will select another winner at random. Good luck, everyone!

Conditions:

By submitting an entry (Photograph) via Facebook or Twitter to Princeton Hydro’s 2018 #LakesAppreciation Month Contest, you agree to the following: You represent and warrant that:

  • You are the sole and exclusive author and owner of the Photograph submitted and all rights therein; and
  • You have the full and exclusive right, power, and authority to submit the Photograph; and
  • You irrevocably grant Princeton Hydro a non-exclusive, worldwide, royalty-free, perpetual license to use the Photograph in any manner related to the Contest, including all associated use, reproduction, distribution, sublicense, derivative works, and commercial and non-commercial exploitation rights in any and all media now known or hereafter invented, including, but not limited to public relations purposes, posting on social media accounts, and/or for company marketing materials; and
  • No rights in the Photograph have been previously granted to any person, firm, corporation or other entity, or otherwise encumbered such that the prior grant would limit or interfere with the rights granted to Princeton Hydro herein; and
  • No part of your Photograph defames or invades the privacy or publicity rights of any person, living or decreased, or otherwise infringes upon any third party’s copyright, trademark or other personal or property rights.

PHOTOS: Columbia Dam Removal

VIDEO: “Columbia Lake Dam when the water level was 18 inches to 2 feet lower”
Video courtesy of Matt Hencheck

In Northwest New Jersey on the Paulins Kill, an important tributary to the Delaware River, the century-old hydroelectric Columbia Dam is actively being removed. Princeton Hydro was contracted by American Rivers to investigate, design, and apply for permits for the removal of this dam for the New Jersey chapter of The Nature Conservancy. Our team of engineers and ecologists studied the feasibility of removal by collecting sediment samples, performing bioassay tests, and conducting a hydraulic analysis of upstream and downstream conditions. We’re excited to report that the Columbia Dam removal has officially commenced!

The New Jersey Department of Environmental Protection started draining water from Columbia Lake a few weeks ago, which was the first step in removing the dam. Princeton Hydro has subsequently been contracted by The Nature Conservancy to provide construction administration services.  Photos below show the water at lowered levels at the impoundments.

“Dewatering Impoundment” Photo by Princeton Hydro

“An aerial drone snapshot when water levels were down about 5 feet at the upper impoundment” Photo courtesy of the New Jersey Chapter of The Nature Conservancy

Last week, the first hammer hit the wall of a downstream dam remnant, officially starting the removal process.

“The first hammer”  Photo courtesy of Dale Bentz, RiverLogic Solutions

The dam removal process will last a few weeks, as the contractor actively knocks down the thick concrete wall.

“Pressure and time”  Photo courtesy of Dale Bentz, RiverLogic Solutions

“Halfway there”  Photo courtesy of Dale Bentz, RiverLogic Solutions

Once the dam is removed, there is a high probability that populations of American Shad and River Herring will be restored. It may also enhance American Eel migration. As a coldwater fishery, this reach also has significant potential for trout species, as well as Smallmouth Bass.

(Top) Before: Photo of the Columbia Dam before construction. (Bottom) After: Princeton Hydro’s rendering of what the river will look like once the dam is removed.

“It is very exciting to be a part of such a monumental effort for the restoration of the Paulins Kill. This river, once a major migration route for diadromous fish like American Shad, will once again be a nursery for this Delaware River icon,” said Geoffrey Goll, PE, President and co-founder of Princeton Hydro. “The removal of these dams will also restore the functions and values of a riparian corridor and floodplain, eliminate costs to the taxpayer for the maintenance of a dam and lake, and provide additional riverine recreational opportunities. I expect to see the same resilience and positive impact to the Delaware River as the recent barrier removals on another major NJ tributary, the Musconetcong River. It is a win-win for NJ, and with The Nature Conservancy at the helm and expert guidance from American Rivers, it has been an experience of a career.”

This project could not have been possible without the hard work and dedication of the following partner organizations: The Nature Conservancy of New Jersey, American Rivers, U.S. Fish and Wildlife Service, RiverLogic Solutions, NJDEP Division of Fish and Wildlife Service, and SumCo EcoContracting.

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 fish passage and dam removal engineering services, visitbit.ly/DamBarrier.


This video from 2016 features the Nature Conservancy’s New Jersey State Director Barbara Brummer, Ph.D. speaking on the Columbia Dam removal. Video credit: NJ Herald.

Dam Removal on the Moosup River

Moosup River

The Moosup River is a beautiful 30-mile-long, trout river flowing through Connecticut and Rhode Island, eventually emptying into the Quinebaug River.

Several dams, most originally built in the 1800s or early 1900s, impeded the river’s natural flow, impaired habitat, fragmented the river system, and prevented fish from swimming upstream to their native spawning grounds.

In 2013, American Rivers, CTDEEP Fisheries, and Natural Resources Conservation Service began collaborating on the removal of multiple dams and remnant dams as part of a larger project to restore connectivity to the Moosup River in the Town of Plainfield. Princeton Hydro and RiverLogic Solutions were contracted to provide design-build and permitting services.

As part of this larger multi-year effort, five dams are planned for removal from the Moosup River. The most downstream barrier, the Hale Factory Dam was removed in 2014. The remnants of the toppled Griswold Rubber Dam were removed in 2015. In 2017, the removal of Brunswick Mill Dam #1 was completed. And, two more dams, downstream of New Brunswick Mill Dam #1, are currently under consideration for removal. When fully completed, the Moosup River Dam Removal Project will reconnect fish habitats along 6.9 miles of the Moosup River.

 

Hale Factory Dam

The Hale Factory Dam was constructed of a boulder core capped in a one-foot-thick concrete layer. The dam was partially breached as the concrete cap had deteriorated severely over the years, allowing flow to pass between boulders and allowing the normal pool elevation to drop substantially from its former design height.

The resource delineation conducted on site identified a vernal pool with an 18 inch culvert outlet that discharged 90 feet upstream of the dam. To preserve this ecological resource on the site, the vernal pool was not disturbed during the dam removal.

Princeton Hydro provided a field assessment, sediment characterization and analysis, final design and permit application package for the full removal of the Hale Factory Dam. Full removal of the dam entailed demolition and removal of the concrete, and re-use of the natural cobbles and boulders from the dam to create in-stream habitat features. Once completed, the river and its boulders appeared as if placed by nature itself, with the former dam’s presence indicated only by the age-old lichen covered field stone walls leading up to the banks.

 

Griswold Rubber Dam

The Griswold Rubber Dam was in a gravel-cobble reach of the river approximately 80 feet wide in the Village of Moosup and was adjacent to the 1992 expansion of the Griswold Rubber factory.  At one time, the dam stood approximately 10 feet high and 150 feet long. The dam was constructed of a large segmented concrete slab that had since toppled over and was lying nearly flat on the river bed in multiple sections. The dam structure, having failed, served no useful purpose. Despite being toppled, the dam still presented a deterrent to the effective movement of aquatic organisms at normal to low flows and was therefore worthy of complete removal to restore river connectivity.

Princeton Hydro conducted an initial field investigation with RiverLogic Solutions to gain insights regarding the construction approach. Princeton Hydro then followed-up with a more detailed assessment of river bed sediment, geomorphic conditions, the likely riverine response, construction access, and other design related issues that were incorporated into design plans and permit applications. The restoration design Princeton Hydro developed aimed to remove the partial barrier to fish passage with as little disturbance to surrounding infrastructure and resources as possible.

 

Brunswick Mill Dam #1

This dilapidated timber crib dam stood approximately 4-feet high and spanned the channel at approximately 130 feet. The timbers ranged from 1.5 to 2.5 feet in diameter and over 20 feet in length; 50 were integrated into the dam. The timber crib was filled with gravel and other debris, and the gravel substrate extended 50 feet upstream. The original dam was significantly higher, but the timber crib spillway deteriorated and gradually collapsed over time and only a portion of the structure remained.

For this project, Princeton Hydro completed sediment investigation, sampling and analysis; hydrologic and hydraulic analysis; and provided design and engineering for full removal of the dam. Princeton Hydro contracted with an archeologist / industrial historian, and together closely observed the dam deconstruction to observe and record how the timber crib had been assembled. Multiple types of iron pins and wooden pegs revealed how the dam had been repaired over the years – findings, old maps, and photos were incorporated into a historical report filed with the state historic preservation office. Princeton Hydro coordinated to have the old timbers salvaged for eventual re-use. Removing the Brunswick Mill Dam #1 was a continuation of the large scale Moosup River restoration effort and paved the way for the potential removal of two more dams downstream in the coming years.

“When a dam is breached and taken out, the tangible results are very quickly noticeable,” said Paul Woodworth, Princeton Hydro Fluvial Geomorphologist. “The return of migratory fish is a very strong indicator of the ecological benefits of dam removal – sometimes after a removal you can see fish immediately swimming upstream. Removing dams also improves safety in nearby communities, reestablishes the natural flow of sediment, improves water quality, provides new recreation opportunities, and restores habitats for fish and wildlife.”

Click here to read more about Princeton Hydro’s engineering services for the restoration and removal of dams.

EMPLOYEE SPOTLIGHT: Meet the Interns

This summer, Princeton Hydro is hosting five interns, each of whom are passionate about protecting water quality and preserving our natural resources. From June to August, our interns will gain professional work experience in a variety of subject areas, ranging from stormwater management to dam restoration to ecological design to lake management and much more. They are assisting on a variety of projects, getting real-world practice in their areas of study, and working with a Princeton Hydro mentor who is helping them gain a deeper understanding of the business of environmental and engineering consulting and setting them up for career success.

 

Meet Our Interns:

 

Ivy Babson, Environmental Science Intern

Ivy is a rising senior from University of Vermont, majoring in Environmental Science with a concentration in Ecological Design, and minor in Geospatial Technologies. In the future, she hopes to implement ecological design in urban areas and create a sustainable environment that would allow future generations to care for and interact with a healthy earth.

Ivy will work alongside Senior Aquatics Scientist Dr. Jack Szczepanski and the Princeton Hydro Aquatics team on projects related to lake and pond management, including fisheries management, data collection and analysis, and water quality monitoring. Recently, Ivy assisted Aquatic Ecologist Jesse Smith in completing an electrofishing survey in a Northern New Jersey river.

Learn more about Ivy.

 

Marissa Ciocco, Geotechnical Intern

Marissa is entering her fourth year at Rowan University where she is a Civil and Environmental Engineering major with a Bantivoglio Honors Concentration. In the future, Marissa hopes to work towards creating a greener and safer environment.

During her internship, Marissa will be mentored by Jim Hunt P.E., Geotechnical Engineer, who has already engaged Marissa in a few construction oversight projects, including a culvert restoration effort in Medford Lakes, NJ and observing geotechnical borings in Evesham, NJ.

Learn more about Marissa.

 

Will Kelleher, Environmental Science Intern

Will is a rising junior at the University of Vermont, studying Environmental Science with a concentration in Water Resources. His current career interests are focused around wetlands restoration and water chemistry. He recently spent two weeks studying water management and sustainable technology in the Netherlands and in the past has helped with biological and chemical stream monitoring with Raritan Headwaters Association.

Mentored by Senior Aquatics Scientist Dr. Jack Szczepanski, Will’s area of focus will be lake and pond management. He’ll spend most of his time in the field alongside members of the Aquatics Team collecting water quality data and mapping aquatic plants, learning about aquatic habitat creation, and implementing various invasive aquatic weed control efforts.

Learn more about Will.

 

Veronica Moditz, Water Resources Intern

We are thrilled to welcome back Veronica, who interned with us last year, and is in her final year at Stevens Institute of Technology, pursuing a Bachelor Degree in Environmental Engineering and a Master Degree in Sustainability Management. She is currently the secretary for Steven’s Environmental Engineering Professional Society chapter. In the future, she hopes to work on more sustainable approach to engineering problems.

Veronica will work alongside Project Engineer and Construction Specialist Amy McNamara, EIT, and Mary L. Paist-Goldman, P.E., Director of Engineering Services, on a variety of environmental engineering projects. Most recently, she assisted with a construction oversight and stormwater management project in Morris County, NJ.

Learn more about Veronica.

 

Tucker Simmons, Water Resources Engineer

Tucker is a Civil and Environmental Engineering major at Rowan University focusing on Water Resources Engineering. His Junior Clinic experience includes the study of Bio-Cemented sand and the Remote Sensing of Landfill Fires. In the future, Tucker hopes to work on creating a more sustainable environment.

Throughout his internship, Tucker will be mentored by Dr. Clay Emerson, P.E. CFM, Senior Water Resources Engineer, and will work on projects related to stormwater management, hydrologic and hydraulic analysis, and various aspects of environmental restoration. He recently assisted with a sink hole inspection in Tredyffrin Township, PA and mapped the water depths of a lake in Bucks County, PA.

Learn more about Tucker.

 

Stay tuned for updates on what our interns are working on!

 

 

 

A Scientist’s Journey to the Antarctic: A Princeton Hydro Blog Series

This two-part blog series takes us on an adventure to the southernmost continent and explores how changes to Antarctica’s ecosystem have worldwide impacts.

Welcome to Part Two: The Continent of Science

Antarctica, the most remote and inaccessible continent in the world, is also, on average, the coldest, windiest and driest continent. Quick Fact: Antarctica is actually a desert! Additionally, with an average elevation of about 7,200 feet above sea level, it is also the world’s highest continent.

There are no native people in Antarctica, but scientists from all over the world visit the continent to conduct research. During the summer, approximately 4,000 scientists visit “the continent of science” to carry out research in a wide range of physical and biological sciences – from the vastness of space to the minutest scale of microorganisms. The research conducted here has helped to highlight global problems, including climate change.

Tourists also visit Antarctica during the summer to enjoy the spectacular scenery and abundant wildlife. In Part One of our two-part blog series, we take you on an Antarctic journey through Sophie Breitbart’s experience aboard the National Geographic Explorer ship. Sophie saw a variety of wildlife during her 10-day educational excursion, including Crabeater and Leopard seals, gentoo and Chinstrap Penguins, Humpback and Killer whales, migrating Red Knots, and more.

Polar tours like the National Geographic Lindblad Expedition help to raise climate change awareness and create lifelong wildlife ambassadors, and the profits from responsibly managed tourism help to fund critical scientific expeditions to the Antarctic.

Just last year, a research mission conducted by the National Oceanic and Atmospheric Administration discovered that sea ice cover in the Antarctic is near record lows – 18.2%, or 520,000 square miles, below the 1981-2010 average. That is the second lowest sea ice report since record-keeping began in 1979, with the first being recorded in 2016. Smaller ice shelves in the Antarctic Peninsula are currently retreating, breaking up into vast fields of icebergs, likely due to rising temperature and surface melting.

Snow and ice make up more than 95% of Antarctica’s surface terrain. The continental ice sheet contains approximately seven million cubic miles of ice, representing about 90% of the world’s total ice. The average thickness is about 1.5 miles. To understand its extent, if Antarctica’s ice were to melt today, global sea levels could rise 150 – 200 feet. It’s massive.

Climate change impacts are already being documented in Antarctica. The Antarctic Peninsula’s glaciers have been warming faster than the rest of the continent. As the snow and ice decrease, the land cover increases and absorbs more heat, which in turn increases the rate of warming. In 2017, a study published in Current Biology found that over last 50 years, temperatures have been rising, and therefore have caused a steady growth of moss on the continent.  So, scientists are now predicting that, “terrestrial ecosystems will alter rapidly under future warming, leading to major changes in the biology and landscape of this iconic region—an Antarctic greening to parallel well-established observations in the Arctic.”  And, another study by researcher Bill Fraser has reported that Adélie Penguin populations have decreased from 32,000 breeding pairs to 11,000 in 30 years because of the changes in temperature.

Changes to the global sea ice cover reported by NOAA not only carry major implications for the continent of Antarctica, but for the entire world. 97% of actively publishing climate scientists agree that earth’s climate is warming, and the evidence that the Arctic’s ice caps are melting at an accelerated rate due to climate change is blaring. And, more than 62% of Americans say they are at least “somewhat worried” about global warming. Yet, not many people are taking daily actions to slow global climate change.

We must make every effort we can to limit our own carbon footprint and mitigate climate change. It has been said that there are most likely no greater ambassadors for Antarctica than the tourists who have been there and return home to share information about the need for its protection.

When Sophie returned from her trip, she said “I became an environmental scientist because I have a passion to conserve biodiversity. Being immersed in this wild place and experiencing firsthand the magnificent yet fragile Antarctic landscape acts as a reminder of why it’s so important to do this work. Those memories inspire me to keep at it.”

To learn more about Antarctica and what scientists with World Wildlife Fund are doing to protect it, go here. If you have any questions for Sophie about her journey, please email us or comment below.

 

Sophie Breitbart worked for Princeton Hydro from March 2016 until May 2018, first as an intern and then as a staff scientist. She is now pursuing her PhD in Ecology and Evolutionary Biology at the University of Toronto, where she will study how urban development affects the ecology and evolution of interactions between the plant common milkweed, its herbivores, and pollinators.