New Video Celebrates 50th Anniversary of Wild & Scenic Rivers Act


Communities across the nation are preparing to celebrate the 50th anniversary of the Wild and Scenic Rivers Act. This landmark legislation passed by Congress in October 1968 safeguards the free-flowing character of rivers by precluding them from being dammed, while allowing the public to enjoy them. It encourages river management and promotes public participation in protecting streams.

As part of the celebration, the National Park Service released a new video highlighting a handful of ‘Wild and Scenic’ designated rivers in the Northeast – the Farmington, Sudbury, Assabet, Concord, and Musconetcong Rivers – along with the organizations and community volunteers who work together to protect and care for these rivers.

Princeton Hydro is proud to work with two of the river stewards featured in the video: Musconetcong Watershed Association (MWA) and Farmington River Watershed Association (FRWA).

The Musconetcong River:

Designated ‘Wild and Scenic’ in 2006, the Musconetcong River is a 45.7-mile-long tributary of the Delaware River in northwestern New Jersey.

Princeton Hydro has been working with MWA in the areas of river restoration, dam removal, and engineering consulting since 2003 when the efforts to remove the Gruendyke Mill Dam in Hackettstown, NJ began. To date, Princeton Hydro has worked with MWA to remove five dams on the Musconetcong River, the most recent being the Hughesville Dam.

As noted in the video, the removal of these dams, especially the Hughesville dam, was a major milestone in restoring migratory fish passage along the Musconetcong. Only a year after the completion of the dam removal, American shad returned to the “Musky” for the first time in 250 years.

“The direction the river is moving bodes well for its recovery,” said Princeton Hydro President Geoff Goll, P.E., who was interviewed in the 50th anniversary video. “This multidisciplinary approach using ecology and engineering, paired with a dynamic stakeholder partnership, lead to a successful river restoration, where native fish populations returned within a year. ”

The Farmington River:

The Upper Farmington River, designated as ‘Wild and Scenic’ in 1994, stretches 14-miles through Connecticut starting above Riverton through the New Hardford/Canton town line. The river is important for outdoor recreation and provides critical habitat for countless wildlife.

Credit: FWRA.orgBack in 2012, Princeton Hydro worked with the FRWA and its project partners to remove the Spoonville Dam. Built in 1899 on the site of a natural 25-foot drop in the riverbed, the dam was originally a hydropower facility. The hurricanes and flood of 1955 breached the dam, opening a 45-foot gap and scattering massive dam fragments in the riverbed downstream. The remnant of the main dam persisted for decades as a 128-foot long, 25-foot high obstacle in the channel. The river poured through the breach in a steep chute that stopped American shad from proceeding further upstream to spawn.

The project was completed, from initial site investigation through engineering assessment and final design, in just six months. The dam removal helped to restore historic fish migrations in the Farmington River (including the American shad) and increase recreation opportunities.

Wild & Scenic Rivers Act:

Credit: NPS.govAs of December 2014 (the last designation), the National ‘Wild and Scenic’ System protects 12,734 miles of 208 rivers in 40 states and the Commonwealth of Puerto Rico; this is a little more than one-quarter of 1% of the nation’s rivers. By comparison, more than 75,000 large dams across the country have modified at least 600,000 miles, or about 17%, of American rivers.

In honor of the 50th anniversary of the Act and in an effort to designate many more miles of river as ‘Wild and Scenic,’ four federal agencies and four nonprofit groups are coordinating nationwide events and outreach. Managing agencies are the Bureau of Land ManagementFish and Wildlife ServiceForest Service, and National Park Service, along with American RiversAmerican WhitewaterRiver Network and River Management Society. Go here for more info:


Welcome to the second installment of Princeton Hydro’s multi-part blog series about aquatic organism passage.

What you’ll learn:

  • How does promoting aquatic organism passage benefit ecosystems as a whole?
  • How can others, including people, benefit from aquatic organism passage?
  • How has Princeton Hydro supported it?

Photo by Princeton Hydro Founder Steve Souza

Fostering Ecological Balance in Food Webs

A major consequence of poorly designed culverts published in the NRCS' "Federal Stream Corridor Restoration Handbook"is the destabilization of food webs. Sufficient predators and prey must exist to maintain a balanced food web. For example, freshwater mussels (Unionidae) are a common snack among fish. A mussel’s life cycle involves using certain fish as a host for their larvae until these microscopic juveniles mature into their adult forms and drop off. During this period, the host fish will travel, effectively transporting a future food source with it.

In the presence of habitat fragmentation, the isolation of these symbiotic relationships can be devastating. Some mussel species rely on a small circle of fish species as their hosts, and conversely, some fish species rely on specific mussel species as their food. If a fish species is separated from its mussel partner, food shortages owing to a declining adult mussel population can occur.

Widespread Benefits to Flora, Fauna, and People

A shift in the 1980s recognized the importance of redesigning road-stream crossings for several reasons, including restoring aquatic organism passage and maintaining flood resiliency. Replacing culverts with larger structures that better facilitate the movement of both water and aquatic organisms benefit all species. Roads constructed over streams allow people to travel across natural landscapes while culverts that are fish-friendly convey water at a rate similar to the surrounding landscape, reducing scour in stream beds.

A man fly fishes as his dog sits by his side at Ken Lockwood Gorge, Hunterdon County. Photo from State of New Jersey website.

Fish, as well as semi-terrestrial organisms like crabs and salamanders, can take advantage of more natural stream environments and complete their migrations. Anglers appreciate healthy, plentiful fish populations nearly as much as the fish themselves. Recreation and economic growth also improve when streams regain the aquatic biological communities once lost through habitat fragmentation. According to USFWS, for every dollar spent on restoration through the Partners for Fish and Wildlife Program and Coastal Program Restoration Project, states gain $1.90 of economic activity. Stream restoration improves fish and wildlife habitat, which directly supports and enhances recreation opportunities for outdoor enthusiasts thus resulting in increased tourism-related spending and job growth.

Aquatic Organism Passage in Action at Princeton Hydro

Princeton Hydro recently completed a project to facilitate aquatic organism passage for river herring in Red Brook in Plymouth, Massachusetts. Read all about it here!

For an introduction to aquatic organism passage, be sure to check out the first post in this multipart-series.


“Aquatic Organism Passage through Bridges and Culverts.” Flow. Vermont Department of Environmental Conservation’s Watershed Management Division, 31 Jan. 2014. Web. 14 Mar. 2017.

Hoffman, R.L., Dunham, J.B., and Hansen, B.P., eds., 2012, Aquatic organism passage at road-stream crossings— Synthesis and guidelines for effectiveness monitoring: U.S. Geological Survey Open-File Report 2012-1090, 64 p.

Jackson, S., 2003. “Design and Construction of Aquatic Organism Passage at Road-Stream Crossings: Ecological Considerations in the Design of River and Stream Crossings.” 20-29 International Conference of Ecology and Transportation, Lake Placid, New York.

Kilgore, Roger T., Bergendahl, Bart S., and Hotchkiss, Rollin H. Publication No. FHWAHIF-11-008 HEC-26. Culvert Design for Aquatic Organism Passage Hydraulic Engineering Circular Number 26. October 2010.

Michigan Natural Features Inventory. Freshwater Mussels of Michigan. Michigan State University, 2005.


Musconetcong Watershed Association Presents Princeton Hydro President with Prestigious “Friend of the River” Award


Musconetcong Watershed Association (MWA) held a dinner to celebrate its 25th anniversary as well as the 150th anniversary of the Asbury Grist Mill, which the MWA is working to restore. The evening included a cocktail hour, a buffet dinner, silent auction, remarks by the MWA President Tish Lascelle and Executive Director Alan Hunt, and a presentation of awards.

The MWA presented Princeton Hydro PresiPhoto by Tish Lascelle, President, Musconetcong Watershed Associationdent Geoff Goll, PE with the “Friend of the River” Award. This award, which has only been given seven times in MWA’s 25 years of service, recognizes individuals who have made a significant and sustainable difference in the Watershed and helped to advance its mission. Recipients of the Award have also demonstrated outstanding leadership through their volunteer efforts or partnerships with MWA.

Geoff was honored to receive the award alongside Paul Kenney of the National Park Service and Richard C. Cotton, a Managing Partner of the Hawk Pointe Golf Club and Asbury Farms Real Estate. Paul was assigned the Musconetcong River in late 2003 and was instrumental in obtaining the Musconetcong River’s Wild and Scenic Designation in 2006. He has continued to be an excellent resource of the National Park Service.  Richard is a founding member of the MWA’s Board of Trustee’s and continues to serve on the Board. He has dedicated his professional life to striking a balance between economic growth with environmental protection.

Geoff has been working with MWA in the areas of river restoration, dam removal, and engineering consulting since 2003, when the efforts to remove the Gruendyke Mill Dam in Hackettstown, NJ began. He has since worked with the Princeton Hydro team to remove five dams on the Musconetcong River, the most recent being the Hughesville Dam

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.

During the anniversary dinner, participants also got a sneak peek of a new video from the National Park Service that is set for public release in 2018. The video celebrates the upcoming 50th anniversary of the Federal Wild and Scenic Rivers Act, under which the Musconetcong River is protected, and explores the importance of free-flowing rivers and why Americans treasure them. Representing Princeton Hydro at the awards dinner were Vice President Mark Gallagher, his wife Jennifer, Geoff and his wife Amy, and Director of Engineering Services Mary Paist-Goldman, PE.












Princeton Hydro Dam Removal Work Featured at Brazilian Workshop

As Brazil is in the midst of a dam-building boom, scientists and engineers gathered at a workshop in Brazil to discuss, “Dam Removal & Optimizing Hydro Locations to Benefit Species Diversity in Brazil.”

Laura Wildman, P.E., Water Resources and Fisheries Engineer and Director of Princeton Hydro’s New England Regional Office, was invited to speak at the workshop. Her presentation focused on why we remove dams in the U.S. (the key drivers), how we analyze them for removal, and what we are learning through a wide diversity of completed case studies.

“It was fascinating to discuss a topic, such as the removal of dams, right as Brazil is focusing on building more hydro capacity,” said Laura. “Hopefully it is a sign that the hydro industry in Brazil, along with all the great Brazilian fisheries researchers, are quite forward thinking and are determined to maintain their country’s rich species diversity while also enhancing their energy options.”

The workshop, hosted by CEMIG and held at UFMG, involved many universities, including our workshop host Paulo Pompeu from UFLA, Dr. Paul Kemp from University of Southhampton, Dr. Jesse O’Hanley of Kent Business School, and many others.

The gathering inspired a lot of interesting dialogue around dam removal, optimizing locations for new hydro facilities, and how to best sustain connectivity and species diversity. Laura’s presentation entitled “Dam removal in the United States” along with the other conference presentations will be available on the CEMIG website soon or check back here on the Princeton Hydro blog for presentation links.

Aquatic Organism Passage: A Princeton Hydro Blog Series

Introducing part one of a multi-part blog series about aquatic organism passage
What you’ll learn:
  • What is aquatic organism passage?
  • Why is it important?
  • How does Princeton Hydro support it?

This photo from NYS DEC demonstrates a well-designed stream crossing.

Since the US government began allotting funds for building roads in U.S. national forests in the late 1920s, hundreds of thousands of culverts were built across the country. Culverts, or drainage structures that convey water underneath a barrier such as a road or railroad, were originally built with the intention of moving water quickly and efficiently. While this goal was met, many migratory fish and other aquatic organisms could not overcome the culverts’ high-velocity flows, sending them away from their migratory destinations. If the culvert was perched, or elevated above the water surface, it would require the migratory aquatic animals to both leap upwards and fight the unnaturally fast stream current to continue their journeys. Additionally, turbulence, low flows, and debris challenged the movement of aquatic organisms.

Thus, the goal of aquatic organism passage (AOP) is to maintain connectivity by allowing aquatic organisms to migrate upstream or downstream under roads. AOP “has a profound influence on the movement, distribution and abundance of populations of aquatic species in rivers and streams”. These aforementioned species include “fish, aquatic reptiles and amphibians, and the insects that live in the stream bed and are the food source for fish”.

This photo from NYS DEC demonstrates a poorly-designed stream crossing.

A poorly designed culvert can harm fish populations in multiple ways. If sturgeon aren’t able to surpass it, habitat fragmentation prevails. And so, a once-connected habitat for thousands of sturgeon breaks into isolated areas where a few hundred now live. When the population was in the thousands, a disease that wiped out 80% of the population would still leave a viable number of individuals left to survive and mate; a population of a few hundred will be severely hurt by such an event. In sum, habitat fragmentation raises the risk of local extinction (extirpation) as well as extinction in general.

The splintering of a large population into several smaller ones can also leave species more vulnerable to invasive species. Generally, the greater the biodiversity harbored in a population, the stronger its response will be against a disturbance. A dwindling community of a few hundred herring will likely succumb to an invasive who preys on it while a larger, more robust community of a few thousand herring has a greater chance of containing some individuals who can outcompete the invasive.

Aquatic Organism Passage in Action at Princeton Hydro

Princeton Hydro recently teamed up with Trout Unlimited to reconnect streams within a prized central-Pennsylvanian trout fishery.  Our team enabled aquatic organism passage by replacing two culverts in Pennsylvania’s Cross Fork Creek. Read about it here!


“Aquatic Organism Passage through Bridges and Culverts.” Flow. Vermont Department of Environmental Conservation’s Watershed Management Division, 31 Jan. 2014. Web. 14 Mar. 2017.

Hoffman, R.L., Dunham, J.B., and Hansen, B.P., eds., 2012, Aquatic organism passage at road-stream crossings— Synthesis and guidelines for effectiveness monitoring: US Geological Survey Open-File Report 2012-1090, 64p.

Jackson, S., 2003. “Design and Construction of Aquatic Organism Passage at Road-Stream Crossings: Ecological Considerations in the Design of River and Stream Crossings.” 20-29 International Conference of Ecology and Transportation, Lake Placid, New York.

Kilgore, Roger T., Bergendahl, Bart S., and Hotchkiss, Rollin H. Publication No. FHWAHIF-11-008 HEC-26. Culvert Design for Aquatic Organism Passage Hydraulic Engineering Circular Number 26. October 2010.

The Restoration of Bound Brook

To the delight of fish and environmentalists alike, an important step has been made in the removal of the aging spillway of Hunters Pond Dam in Scituate and Cohasset, Massachusetts. The spillway was notched to ensure a gradual release of water from the impoundment, letting Bound Brook flow free again after being dammed for centuries.

As the first barrier upstream from the Atlantic Ocean, the dam’s removal restores 5-miles of river spawning ground and habitat for alewife, blueback herring, American eel, rainbow smelt, sea lamprey and other important species. The removal of Hunters Pond Dam also reduces the threat of dam failure.

Princeton Hydro is proud to be working on this project with T Ford Company, U.S. Fish and Wildlife Service, and many other great partners. The project is funded by grants from the Massachusetts Department of Ecological Restoration and the NOAA.

The project also includes rebuilding a culvert, removing a concrete spillway, and replacing a water main. Stay tuned for more!

The Return of the American Shad to the Musconetcong River

PHOTO/New Jersey Division of Fish and Wildlife biologist Pat Hamilton holds a shad near the Warren Glen Dam

After a 250+ year absence, American shad have returned to the Musconetcong River in Hunterdon and Warren counties. This milestone in the ecological recovery of the river is the result of the removal of dams on the lower Musconetcong several years ago, followed by the removal of the Hughesville Dam in Warren County last year.

Removing the dams opened nearly six miles of the Musconetcong to migratory fish, such as American shad, that spend much of their lives in the ocean but return to rivers and their tributaries to spawn. The shad’s return is a good sign of the overall ecological health and diversity of the river.

Princeton Hydro was proud to partner with the Musconetcong Watershed Association and so many other incredible organizations who came together on the Hughesville Dam Removal project. To date, Princeton Hydro has investigated, designed and permitted five dam removals on the Musconetcong.

The next Musconetcong dam targeted for removal is the 32-foot high Warren Glen Dam, less than a mile farther upstream. It is the largest dam in the river; by comparison, the Hughesville Dam was 15-feet tall.

Princeton Hydro President Geoff Goll, P.E. published this commentary piece titled, “The Return of the American Shad to the Musconetcong River:”

Update (June 15, 2017)NJDEP issued press release on the finding of American shad on the Musky. Bob Shin, NJDEP Commissioner, stated, “[t]he return of shad, a benchmark species indicative of the overall ecological health and diversity of a waterway, is an exciting milestone…. This achievement is the direct result of an ongoing partnership among state and federal agencies, nonprofit groups, and dam owners – all committed to making this beautiful waterway free-flowing again.

On June 7, 2017, Princeton Hydro celebrated along with the Musconetcong Watershed Association (and an excellent story of the MWA, human history of the river, and the efforts to preserve the history and ecology can be found here) and other project partners, the discovery of American shad on the Musconetcong River in NJ, over 250 years after they were blocked from this major tributary of the Delaware River – On September 8, 2016, then Secretary of the Interior, Sally Jewell, held a press conference to celebrate the initial breach of the Hughesville Dam on the Musconetcong River (time lapse of removal is here). The press conference was held as the Department of the Interior via of the US Fish and Wildlife Service provided the funding to remove this obsolete structure through their Hurricane Sandy Recovery funding and the Natural Resource Damage Assessment and Restoration program. In addition to the Honorable Sally Jewell, NJDEP Commissioner Bob Martin, and US Army Corp of Engineers, Philadelphia District Commander Lt. Colonel Michael Bliss, were also on hand to speak about the importance of the Hughesville Dam removal and dam removal in general. To have such dignitaries at the highest levels of our Federal and State government speak at a project our firm designed was truly an honor and privilege. It was a great day to celebrate the next obsolete dam on the Musconetcong River to fall to the progress of river restoration. However, this would pale in comparison to the news we received on Wednesday, June 7, 2017, when the NJ Division of Fish and Wildlife confirmed the presence of the American shad (Alosa sapidissima) above the Hughesville Dam!

Ms. Patricia Hamilton, Fisheries Biologist of NJ Fish And Wildlife, reported that they “spotted small schools of American Shad (at most 6 at a time) and captured 4 several hundred yards downstream of the Warren Glen Dam”, five miles from the confluence of the Delaware River. This is the first documentation of American shad on this river in over 250 years! So, what is the big deal you may ask.

The American shad is the Mid-Atlantic and Southeastern United States’ salmon; it is actually a clupeid, a forage type fish closely related to herrings and sardines. Like herrings and sardines, they are a very oily fish, high in omega-3 fats, and low in contamination. It is also a fairly large clupeid, reaching three to eight pounds as adults. Like the salmon, American shad are anadromous, meaning they live the major part of their lives in the ocean and spawn up the coasts’ rivers. The American shad is not a spectacularly looking fish to say the least, and in fact, looks like a “generic” illustration of a fish, unlike the sleek and sexy salmon. It doesn’t even jump. However, this fish is a long distance and endurance swimmer, who’s migration from its hatching in rivers of the East Coast to its primary habitat in the Atlantic Ocean up in the Gulf of Maine, makes it one of the Earth’s great travelers. It can swim nearly 20,000 kilometers in its first five years of life and can dive to depths of up to 375 meters. And like all of its clupeid kindred, it is both a key prey species for many large fish and cetaceans in the Atlantic’s pelagic zone (open ocean) and an important commercial fish. But it is the existence of over-fishing, pollution and dams that had brought this species to its knees in many of the major eastern US rivers.

While the Delaware River shad and herring species have rebounded somewhat from low populations in the mid-1900s with the advent of the US Clean Water Act, they continue to struggle to regain their numbers, and in fact, there is now a moratorium on catching river herring in the Delaware River, and NJ has a moratorium on the harvesting of shad and herring on its tributaries to the Delaware River and Atlantic Ocean. As far as tributary access is concerned, the largest tributaries to the Delaware, the Schuylkill and Lehigh Rivers, are still blocked by dams to their mouths with very little efficiency of fish ladders provided; with their dams having very little success in gaining support for the removal of their blockages. So, any gains in additional spawning habitat for such anadromous species is viewed as a significant victory. The opening of the Musconetcong River to migrating fish will be a large contributor to the rebound of American shad, and other river herring species.

As one of the original 13 colonies, NJ was an integral partner in the start of the United States and early industrial revolution. It has been documented through our research during the dam removal regulatory permit application process on this waterway that the Musconetcong River has been dammed just about all the way to its confluence with the Delaware River since the mid-1700s, and likely much earlier. So, before there was anyone who understood the importance of unimpeded rivers for fish migration, this particular route was cut-off in its entirety, and then remained so for well over 250 years. So, it is understandable that there was no reason to assume that anadromous fish, such as shad, would resume the use of the river in a short period of time; however, there existed the right habitat for them, should they be afforded access…and the hope of the partners working on this river. There were doubters, to be sure, but “lo and behold”, we now know these mighty fish took advantage of an opening almost immediately.

Now, I am not stating that American shad immediately realized that the Hughesville Dam was gone and took a B-line from the Delaware River to the highest unimpeded location. First, other dams downstream of the Hughesville Dam had been removed over the past several years. These dams included the Finesville Dam (for an excellent video of the story of this dam removal, check out this video by the US Fish and Wildlife Service), removed in 2011 and the Reigelsville Dam remnants (there were two additional remnants found when the first foundation was removed) soon after the Finesville Dam was removed. So, it is likely that American Shad had started moving up the river to the base of the Hughesville Dam between 2011 and 2016. Still the response by American shad is nothing short of spectacular. For the over 250 years this species has not been able to use this river, at all, and now, within a span less than six years of dam removal activities, this fish is raring to comeback and, hopefully, spawn and increase their numbers.

And the efforts are not nearly complete for the Musconetcong River. The finding of the American shad five miles upstream from the Delaware River shows that this river can and, now, does support this fish. This generic looking fish, yet awesome product of evolution should only fuel the fire of continued restoration efforts, proof-positive that the labor and funds spent here, in this river, gets results. Such funds and labor (an staggering amount of time, blood, sweat, and tears) are required in order to get the river restoration work done. These projects have received the majority of their backing from the federal government, through grant programs, natural resource damage funds, and direct Congressional authorized funds. Without support from Washington, D.C.,, and Trenton, none of this work would be possible. And to get these funds, required work by the many team partners to prepare applications, meet with federal agencies, and educate the public through open and transparent meetings and communication. This was an impressive effort by the residents of this watershed, professionals who provided their expertise, and the state and federal employees who have dedicated their lives to this kind of work.

The Musconetcong River, with its recovering ecosystem, and its human and non-human inhabitants continue to amaze me in how we should all strive to strike balance between man and nature; and all this is being accomplished in the most densely populated state in the nation.

The finding of American shad gives me reason to cheer, and is why I do what I do. This is it, the return of a species that at one time we had no assurance would return, has returned. This is hope for us, after all.

Read more about Princeton Hydro’s river restoration and dam/barrier services on our website. Please contact us anytime if you have a project you’d like to discuss.

Earth Day Donation Drive:

“Follow Us” to Raise Money for American Rivers

In celebration of Earth Day, help Princeton Hydro donate to American Rivers!

For every new follower we collect on any of our social media channels between now and Earth Day (April 22, 2017), we’ll donate $.50 to American Rivers, an organization dedicated to protecting our precious water resources. Donations help to restore dammed rivers, protect wild rivers and revitalize river communities.

Support American Rivers by following our social media channels and spreading the word. You can find us on Twitter, LinkedIn, Facebook and Instagram.



Princeton Hydro Projects Recap

In Case You Missed It:
A Recap of Projects Recently Completed by the
Princeton Hydro Aquatic & Engineering Departments

Members of our New England Regional Office team conducted a detailed survey at a culvert prioritized for replacement in the Town of Stony Point, New York. This structure was one of several identified as important to both habitat and flood risk during the development of Stony Point’s Road-Stream Crossing Management Plan. The Princeton Hydro team will use the collected data to develop a conceptual design and implementation strategy for a replacement structure using the Stream Simulation design method developed by the U.S. Forest Service.

Special thanks to Paul Woodworth, Fluvial Geomorphologist, and Sophie Breitbart, Staff Scientist, for their excellent work on this project!

The Truxor was put to work dredging a pond in Union Gap, New Jersey. The Truxor is an extremely versatile amphibious machine that can perform a variety of functions, including weed cutting and harvesting, mat algae and debris removal, silt pumping, channel excavation, oil spill clean-up, and much more!

We recently designed and installed a solar-powered aeration system in Hillsborough, New Jersey. Solar pond and lake aeration systems are cost-effective, eco-friendly, sustainable, and they eliminate the need to run direct-wired electrical lines to remote locations. Princeton Hydro designs, installs and maintains various aeration and sub-surface destratification systems for public drinking water purveyors, municipal and county parks, private and public golf courses, and large lake communities throughout the East Coast.

Here’s a look at a project in Elizabeth, New Jersey to clear the area of phragmites. Phragmites is an invasive weed that forms dense thickets of vegetation unsuitable for native fauna. It also outcompetes native vegetation and lowers local plant diversity. Previously, the entire site was filled with phragmites. Late last year, we utilized the Marsh Master to remove the invasive weed. Now that its almost Spring, we’re back at the site using the Marsh Master to mill and cultivate the ground in preparation for re-planting native plant species. A big shout out to our Aquatic Specialist John Eberly for his great work on this project!

In this photo, our intern and engineering student currently studying at Stevens Institute of Technology, Veronica Moditz, is gathering data on the Hughesville Dam removal. She’s using GPS to check the elevation of the constructed riffle on the beautiful Musconetcong River.

Members of the Princeton Hydro team worked in South New Jersey doing annual maintenance on nine stormwater infiltration basins that were also designed and constructed by Princeton Hydro. The maintenance work involves clearing vegetation from the basins to ensure the organic matter does not impede infiltration of the water as per the basins’ design. This project also involves the management of invasive plant species within the basins. Stormwater infiltration basins provide numerous benefits including preventing flooding and downstream erosion, improving water quality in adjacent waterbodies, reducing the volume of stormwater runoff, and increasing ground water recharge.

We recently completed a project in New Jersey for which we used our Truxor machine to dredge a stormwater retention basin. The basin had accumulated large amounts of sediment which were impeding the flow of water into the basin. We equipped the Truxor with its standard bucket attachment and a hydraulic dredge pump. The dredging operation was a success and now the basin is clear and functioning properly.

Stay Tuned for More Updates!

The Plight of Aging Dams, and One Solution

As dams age, the danger to life and property around them increases. If they were to suddenly fail and flood downstream communities and infrastructure, there would be serious loss of property and life. More and more, dam removal has become the best option for property owners who no longer want or can no longer afford the rising cost of maintenance and repair work required to maintain such a complex structure.

The Courier-Post recently published this Commentary piece titled, “The Plight of Aging Dams, and One Solution”, which was written by Princeton Hydro’s Vice President and Principal Engineer Geoffrey M. Goll:

Many of our nation’s dams, while originally intended to provide benefits for mills, water supply and energy generation, are severely aged and unmaintained. Nearly 20,000 of the dams on the Army Corps of Engineers’ National Inventory of Dams – which doesn’t even include many dams that are not inventoried or known about – were built in the 1960s. With expected lifespans of 50 years, these dams have reached their limit. And by 2020, 70 percent of all dams will be over 50 years old. Like roads and bridges, dams also require upkeep, maintenance and eventually removal or rehabilitation.

As dams age, the danger to life and property around them increases. If they were to suddenly fail and flood downstream communities and infrastructure, there would be loss of property and life. The Association of State Dam Safety Officials, the professional organization for dam safety engineering professionals and regulators, estimates there would need to be a $21 billion investment to repair just 2,000 deficient, high-hazard dams. More and more, the removal of dams has become an option for owners who no longer want or no longer can afford the rising cost of maintenance and repair work required to maintain such a complex structure.

For dams like this, removal benefits local economies, and eliminates threats to people and property in local communities. There are also many byproduct benefits, including restoring fish migration routes, improving water quality, restoring floodplain functions and values, and increasing biodiversity.

On Sept. 8, we had the honor of meeting the Secretary of the Interior Sally Jewell during a visit of our Hughesville Dam removal project on the Musconetcong River, located in northwestern New Jersey. This project exemplifies the successes that can be achieved through public-private partnerships, including local communities, state and federal agencies, nongovernmental organizations, and private commercial entities. This is the fifth dam removed on the Musconetcong River by a coalition of stakeholders, led by the Musconetcong Watershed Association. The Department of the Interior (specifically, the U.S. Fish and Wildlife Service) provided funding to remove this very old, out-of-compliance dam.

The success of these partnerships is due to the unique strengths that each organization brings to the table. This project achieved the removal of a flood and safety hazard, and will restore additional river miles for migratory fish, improve water quality by removing the heat sink of the reservoir, and provide additional safe passage for recreation along the river.

It is easy to see why Secretary Jewell chose this site to visit, but the old and outdated dam at Hughesville is far from alone. Across the nation, we need to remove dams like this at a much larger scale – aging dams that no longer are of value to us, but increase the danger to those who live downstream. If we can build on this momentum and start to address the issue of dam safety compliance on a national scale, we can address these threats to American’s safety and strengthen local economies.