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.

Habitat Fragmentation – Culvert Blockages and Solutions

Capture

Culvert that is “perched” due to scour by high velocity flows through the pipe. ©Princeton Hydro.

The Bucks County Chapter of Trout Unlimited (Pennsylvania) and the Cooks Creek Watershed Association were featured in the Summer 2013 edition of Trout magazine, TU’s national publication, for their culvert inventory work in the Cooks Creek watershed.  Princeton Hydro was glad to assist via directly investigating and training of volunteers to inspect and document potential culverts in need of retrofit.  Princeton Hydro also completed design concepts and opinion of costs for two example culverts.  Identified culverts in need of retrofit will help the creek’s wild brown and brook trout.  Princeton Hydro based the training on the Vermont guidelines for rating culverts for pass-ability.  In this small watershed a total of 97 culverts were identified with 32 of them as potential barriers, and 11 identified as “high priority” in need of retrofit.

Why worry about culverts, you say?

One of the most unforeseen danger to the biodiversity in our river networks is habitat fragmentation through un-passable culverts throughout the United States.  While blockages via dams number upward of 100,000 or so, the blockages created by ecologically and biologically inefficient culverts is likely to number in the millions.   The majority of these culverts are located in headwater areas of rivers, which entail greater than 50% of most river miles in a watershed; a large cumulative impact.  As a result, native key headwater species such as brook trout (Salvelinus fontinalis) in the East and cutthroat trout (Oncorhynchus clarkii) in the West have had their historic ranges reduced to a fraction of their former extent.

Historically, culverts were designed by civil engineers to maximize flow capacity and minimize pipe size in order to create the most economical structure for developers, transportation authorities, and municipalities.  The unfortunate by-product of such a design approach is that water velocity through culverts is extremely high, often running in supercritical flow, even during base flow conditions, and the smooth and featureless surfaces in the structure make it extremely difficult to navigate.  To add insult to injury, the high velocity flows also scour and erode the stream channel immediately downstream of the culvert, leaving the pipe too high out of the new channel (“perched pipes”) for organisms to pass.  Downstream water dependent organisms cannot pass upstream to new habitat, and those populations upstream become extirpated due to downstream migration and mortality, and the lack of an ability to return or be replaced.  A study of impacts of fragmentation on brook trout is ongoing by the USGS Conte Anadromous Fish Research Center (USGS CAFRC) and others, and a study recently completed documented the impacts of fragmentation of local populations provides an informative view of the blockage potential of culverted streams.

There is hope in the re-connection of stream habitat through new research and initiatives developed since 1999.  One such approach is through the Stream Simulation design originally developed in its present form at the Washington State Department of Fish & Wildlife and adopted by the US Forest Service, US Fish and Wildlife Service, as well as others, and was also adopted shortly thereafter and refined by the University of Massachusetts, Amherst Extension (Stream Continuity model) for use in Northeastern States (initially in the Massachusetts River and Stream Crossing Standards, and then adopted in similar form by surrounding states).  Through the Stream Simulation/Continuity method, a culvert is not simply measured in terms of hydraulic efficiency, but also in terms of ecological and biological efficiency.

In the most basic terms, Stream Simulation (Continuity) requires a crossing that has a minimum width of the bankfull flow of the natural channel upstream and downstream, plus more width to allow passage of terrestrial organism passage such as reptiles and amphibians (in the UMASS model the increase in width is 20% wider than bankfull, but in the current Washington State model they use 20% plus 2 feet).  The other part of the design requirement is an opening area to length ratio to allow the maximum amount of natural light penetration into the culvert (openess ratio), as many organisms, such as fish, are too intimidated to travel through dark culverts.  Other design requirements include the use of slopes and velocities that allow for fish passage, and roughness (i.e. placement of natural substrate) to also slow down the flow.

The key challenge for the retrofitting of culverts to be more passable is cost.  As with any civil engineering project, the larger it is, the more expensive.  To replace a 36 inch diameter culvert with a 10-14 foot wide structure could increase the cost by 10-fold.  However, there are ways in completing an economic analysis to justify the costs.  For example, most culverts were historically only designed to pass storms up to the 25-year event, but in even more cases, never were sized by engineers.  A larger culvert will increase its capacity and reduce overtopping events that would require road closings and worse, cause the roadway to collapse.  Road closings require emergency management and road crews to set up detours and slowing down commerce, or worse require repetitive reconstruction efforts that, over time, may exceed the cost of installing a Stream Simulation designed culvert.

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Same culvert as in photograph above, after the retrofit using Culvert Simulation. ©Princeton Hydro.

Other ways of encouraging installation of these larger and passable culverts is through the permitting process.  In New England, the US Army Corps of Engineers, allows for a by-pass of a formal review for their approval if the Stream Simulation guidelines are followed. This approach can save a significant amount of time to fast-track a retrofit.  To complement the Corps’ permit facilitation process, the states of Connecticut, Massachusetts, New Hampshire, and Vermont, have developed stream crossing guidelines to meet the Corps’ permit by rule compliance.  These states have even instituted state level regulations requiring aquatic organism passage via the Stream Simulation model.

Princeton Hydro was contracted to design a culvert retrofit to replace a 36 inch diameter culvert with a 12 foot wide arch culvert on a tributary of West Brook which is being monitored as part of the USGS CAFRC research project in Massachusetts.  This retrofit will be used to assess the increase in efficiency of headwater stream accessibility by local brook trout populations.

It would appear that the Stream Simulation or Continuity model is catching on, however, there needs to be more outreach and changes to existing rules in other regions of the US.  Further studies, such as that being conducted by USGS and their partners, will determine the true benefits of increasing culvert fish passage efficiency and bolster the economics of protecting fish populations for future generations.
——-
Geoffrey M. Goll, P.E.
Vice President and Founding Partner

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Dam removals in New Jersey – how did we get here?

In the aftermath of Hurricane Floyd in 1999, it became painfully evident that the many dams in and around the state were woefully obsolete. Obsolescence occurs on a dam when it, either through climactic changes or antiquated designs, is unable to safely pass those infrequent yet highly destructive floods. Obsolescence can also occur when earthen embankments or concrete structures have deteriorated to the point of no longer providing safe resistance to seepage and impounding water behind the dam. The threat to the public living in the path of a potential flood wave that results when a dam suddenly bursts is varied but can have serious consequences and liabilities for dam owners.

Following the hurricane, the NJDEP Bureau of Dam Safety sent letters to all the dam owners in their records reminding them of their obligation to maintain their regulated structures in compliance with the Dam Safety Regulations. It was serendipitous that, at the same time, American Rivers and the National Oceanic and Atmospheric Administration (NOAA) started a program called the “Community-Based Restoration Program River Grants,” whereby grants were made available to remove obsolete dams to allow for migratory fish passage. The Natural Resource Conservation Service (NRCS) and the US Fish and Wildlife Service (USFWS) at the same time started looking to dam removals as meeting the restoration criteria for their funding programs.

These sources of funding were serendipitous as “dam safety compliance” not only means the renovation of a dam to meet current standards, but the elimination of the structure altogether is a means of compliance: no dam, no regulatory requirements. This grant opportunity opened up a whole new set of funding sources for dam owners that did not have the wherewithal or desire to maintain a highly regulated and risky structure.

The first dam to fall in the state for the benefits of dam safety compliance and migratory fish passage was the Harry Pursel Dam on the Lopatcong Creek in Phillipsburg in 2001. The next dams were the Gruendyke Mill Dam and Seber Dam on the Musconetcong River in Hackettstown under the leadership of the Musconetcong Watershed Association in the mid-2000s. Princeton Hydro was proud to be a part of each of those removals, and so many others – from North Carolina to Vermont.

Momentum for the removal of the thousands of obsolete dams across the country has increased; New Jersey has no dearth of them. There are plenty. However, as the recent economic recession has hit the private sector, so too has it impacted the availability of government funds to restore natural resources for the public good. Fortunately, other vehicles have been developed to fund dam removals.

In the past several years, Princeton Hydro completed the first dam removals used for the purpose of offsetting wetlands impacts, through projects in Hunterdon and Ocean County. Now, others are following in the path cleared by these projects to boldly use dam removal for the mitigation of wetlands impacts and other types of natural resource damages.  NJDEP is formally in favor of removing dams in the name of restoration, and is even encouraging the removal of obsolete dams as such projects achieve many positive public safety and environmental goals.

It will be vitally important to maintain creativity for funding opportunities and promote public awareness of the importance of dam removal as a cost effective restoration tool.  As a result, the removal of obsolete dams can continue well into the future. If you are interested in further understanding the regulations in NJ, benefits of removal, and examples illustrating dam removals, please visit the following sites:

American Rivers – Dam Removals in NJ
Other dam removal resources from American Rivers
Clearing House for Dam Removal Information

Geoffrey M. Goll, P.E.
Vice President and Founding Partner

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