Part Two: Damned If You Do, Dammed If You Don’t: Making Decisions and Resolving Conflicts on Dam Removal

Credit: FWRA.org

In this two part blog series piece we take a look at addressing and preventing potential conflicts and the key factors involved in dam removal decision-making – to remove or not to remove.

What to Do About Dams

Typically, the decision to remove a dam is made by varying entities, depending on the regulatory oversight of the dam. In most cases, the dam owner itself is the decision-maker, often deciding that the costs of continuing to operate and maintain the dam are more than removing the dam. State dam safety offices can sometimes order a dam to be removed or lowered if there are major safety concerns. State fish and wildlife offices and environmental organizations are also often involved in the decision-making, particularly when the goals of the project include restoration of habitat for migratory and resident aquatic species. If the dam in question is a hydropower facility, the Federal Energy Regulatory Commission also has the power to order a hydropower dam under their jurisdiction to be removed for both environmental and safety reasons.

Laura Wildman, P.E., dam removal and river restoration expert and Director of Princeton Hydro’s New England Regional Office, says, “Identifying key barriers early on and understanding which of those barriers might have potential solutions versus remain an impediment, is critical to prioritizing limited ecological restoration resources.”

The careful formulation and communication of the benefits for dam removal specific to each project, adequate education of the public, and stakeholder involvement are incredibly important components to dam removal conflict resolution. As is an understanding that not all dams will or should be removed, and that the local community and stakeholders needs/concerns should be fully integrated into the decision-making process.

Key facets of stakeholder involvement, include:

  • Initial Stakeholder Discussions: Gather information and input from all stakeholders involved
  • Field Work & Initial Assessment: Know the project site inside and out, conduct an in-person inspection, and gather all of the initial data needed to have an informed discussion
  • Report Back with Results, without Judgement: Share the current state of the dam with stakeholders & regulators, without implying any solution or recommendation
  • Detailed Analysis, Feasibility & Alternatives Assessment: Collaboratively select alternative options, and include for a discussion of the alternative analysis process in the pre-application regulatory and stakeholder meetings
  • Formal Regulatory Review w/ Public Meetings: Present solution and/or submit engineering design and permit applications to regulators, and host public meetings to inform the community about the timeline and status.  Some public meetings are required as part of the regulatory process, however, it is important to keep the stakeholders involved in the process. So, additional meetings or presentations are recommend for true engagement.
  • Implementation: If the solution is to remove or repair the dam, continue to update the community about the status and timeline of construction. Local residents, elected officials, and nonprofit groups could be your best allies in keeping everyone informed.

It’s crucial to keep stakeholders and general public informed throughout the process via regular social media and traditional media outreach. Successful projects are based on a transparent process that integrates the local community.  It is the local community that then becomes the environmental stewards of the restored river system.

Celebrating the start of the Columbia Dam removal with the New Jersey Nature Conservancy, American Rivers, Princeton Hydro, USFWS, NJDEP, the local community, and other stakeholders.

 

Analyzing Dams for Removal

There are few “easy” dam removal decisions. Most dams have both positive and negative impacts. The challenge in making a sound decision about whether or not to remove a dam is to identify all of the costs and benefits of keeping (and eventually repairing or replacing) that particular structure, as well as the costs and benefits of removing it, and balance the findings to determine the best option. It is important to ensure that the full range of costs and benefits are identified.

Working through the many issues involved in deciding to keep or remove a dam can offer surprising conclusions that can lead to a reasoned approach – reducing subjectivity and increasing objectivity. The key issues typically investigated include:

  • Impounded sediment
  • Infrastructure/utility impacts
  • Current use (& economic value of dam)
  • Environmental concerns & benefits
  • Geomorphic equilibrium
  • Public health & safety
  • Flooding & hydrologic impacts
  • Aesthetic & sentimental value
  • Historic/archeological
  • Community concerns
  • Sensitive or invasive species
  • Water rights
  • Cost & funding availability

When making a final decision, it’s important to critically examine all factors to understand the influences on the decision. No matter the final outcome, at least it will be a well-informed process, and the information and understanding gained can help shape future decisions.

Although each dam removal project is unique, we developed a standard process that we follow:

While there is often no definitive answer to a question about whether a particular dam should be removed, there is a right and wrong way to go about making a dam removal decision. A good dam removal/retention decision is one that is based on an assessment of all the facts, collaboration with all stakeholders, and objective criteria.

Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of dozens of dams throughout the Northeast.  To contact us and learn more about our fish passage and dam removal engineering services, visit: bit.ly/DamBarrier.

Revisit part-one of this blog series:

Part One: Damned If You Do, Dammed If You Don’t: Making Decisions and Resolving Conflicts on Dam Removal

Part One: Damned If You Do, Dammed If You Don’t: Making Decisions and Resolving Conflicts on Dam Removal

People have been building dams since prerecorded history for a wide variety of economically valuable purposes including water supply, flood control, and hydroelectric power. Back in the 1950s and 60s, the U.S. saw a boom in infrastructure development, and dams were being built with little regard to their impacts on rivers and the environment. By the 1970s, the rapid progression of dam building in the U.S. led researchers to start investigating the ecological impacts of dams. Results from these early studies eventually fueled the start of proactive dam removal activities throughout the U.S.

Despite the proven benefits of dam removal, conflicts are a prevalent part of any dam removal project. Dam removal, like any other social decision-making process, brings up tensions around economics and the distribution of real and perceived gains and losses. In this two part blog series, we take a look at addressing and preventing potential conflicts and the key factors involved in dam removal decision-making – to remove or not to remove.

Why We Remove Dams

The primary reasons we remove dams are safety, economics, ecology, and regulatory. There has been a growing movement to remove dams where the costs – including environmental, safety, and socio-cultural impacts – outweigh the benefits of the dam or where the dam no longer serves any useful purpose. In some cases, it’s more beneficial economically to remove a dam than to keep it, even if it still produces revenue. Sometimes the estimated cost of inspection, repair, and maintenance can significantly exceed the cost of removal, rendering generated projected revenue insignificant.

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

The goal of removal can be multi-faceted, including saving taxpayer money; restoring flows for migrating fish, other aquatic organisms, and wildlife; reinstating the natural sediment and nutrient flow; eliminating safety risks; and restoring opportunities for riverine recreation.

Moosup River

Common Obstacles to Dam Removal

Dam removal efforts are often subjected to a number of different obstacles that can postpone or even halt the process altogether. Reasons for retaining dams often involve: aesthetics and reservoir recreation; water intakes/diversions; hydroelectric; quantity/quality of sediment; funding issues; cultural/historic values of manmade structures; owner buy-in; sensitive species; and community politics.

Of those common restoration obstacles, one of the more frequently encountered challenges is cost and funding. Determining who pays for the removal of a dam is often a complex issue. Sometimes, removal can be financed by the dam owner, local, state, and federal governments, and in some cases agreements are made whereby multiple stakeholders contribute to cover the costs. Funding for dam removal projects can be difficult to obtain because it typically has to come from a variety of sources.

Anecdotally, opposition also stems from fear of change and fear of the unknown. Bruce Babbitt, the United States Secretary of the Interior from 1993 through 2001 and dam removal advocate, said in an article he wrote, titled A River Runs Against It: America’s Evolving View of Dams, “I always wonder what is it about the sound of a sledgehammer on concrete that evokes such a reaction? We routinely demolish buildings that have served their purpose or when there is a better use for the land. Why not dams? For whatever reason, we view dams as akin to the pyramids of Egypt—a permanent part of the landscape, timeless monuments to our civilization and technology.”

Negative public perceptions of dam removal and its consequences can seriously impede removal projects. Although there are many reasons for the resistance to dam removal, it is important that each be understood and addressed in order to find solutions that fulfill both the needs of the environment and the local communities.

Stay tuned for Part Two of this blog series in which we explore strategies for analyzing dams and what goes into deciding if a dam should remain or be removed.

October Events Spotlight: Conferences, Workshops & Galas

Throughout October, Princeton Hydro is proud to participate in a number of conferences and events on topics ranging from floodplain management to ecological restoration to dam removal:

October 10: Society for American Military Engineers (SAME) MEGA Maryland Small Business Conference

The conference, being held in Baltimore, gives small and minority businesses in the architecture, engineering and construction industries the opportunity to come together with federal agencies in order to showcase best practices and highlight future opportunities to work in the federal market. The program consists of networking events, a variety of speakers and small business exhibits. Be sure to stop by the Princeton Hydro booth to say hello to President Geoffrey Goll, P.E. and Communications Strategist Dana Patterson.

LEARN MORE & REGISTER

 

October 11: Great Swamp Gala & Silent Auction

The Great Swamp Watershed Association, a nonprofit organization dedicated to protecting and improving the water resources of the Passaic River region, is hosting its 2018 Gala & Silent Auction. This year’s event is being, held in honor of former New Jersey Governor Thomas Kean, for his environmental leadership during his administration for enacting landmark protections for New Jersey’s shoreline and freshwater wetlands. present and future generations. The evening will include a cocktail hour, dinner banquet, expansive silent auction, and remarks delivered by Governor Kean. Princeton Hydro is proud to be a Benefactor of the event and looking forward to attending.

LEARN MORE & REGISTER

 

October 11 – 13: Atlantic Estuarine Research Society (AERS) Fall Meeting

The theme of this year’s AERS Fall Meeting is “The power of framing your message: It’s not what you say, it’s how you say it!” Participants will gather at Stockton University to hear a variety of ignite-style presentations about misconceptions that typically surround scientific work, how to address them, and how to re-frame your message to be better understood by the general public and other non-scientists and increase stakeholder involvement. Princeton Hydro’s Senior Aquatics Scientist Jack Szczepanski, PhD will be attending the conference; chat with him to learn more about our pond and lake services.

LEARN MORE

 

October 11 – 13: Society for Ecological Restoration (SER) New England 2018 Regional Conference

This year’s SER New England conference brings together stewards, researchers, students, regulators, community activists and practitioners to explore innovative ecological restoration techniques and projects that connect communities within and across ecosystems. The conference includes a variety of plenary talks, field trips, workshops and a keynote address, which will be given by Stewart Diemont of SUNY College of Environmental Science and Forestry. The keynote, titled “Learning from the People and the Land: Traditional Ecological Knowledge Toward Restoration of Ecosystems and of our Connection with Nature,” is free and open to the public.

Members of the Princeton Hydro are attending the conference and leading two sessions: Laura Wildman, Water Resources and Fisheries Engineer, is leading a workshop about implementing dam removal to restore rivers. Paul Woodworth, Fluvial Geomorphologist, is presenting on the post-dam removal monitoring of active and passive restoration approaches utilizing the Hyde Pond Dam removal as a tangible example.

LEARN MORE & REGISTER

 

October 11: Hudson-Delaware Chapter of the Society of Environmental Toxicology and Chemistry (HDC-SETAC) 2018 Fall Workshop

HDC-SETAC is a professional society for scientists, engineers and related disciplines concerned with environmental science and health throughout the Hudson River and Delaware River metropolitan area. The 2018 Fall Workshop, being held at Villanova University, aims to enhance participants’ knowledge of “Harmful Algal Blooms and other Emerging Contaminants.” Princeton Hydro’s Director of Aquatic Programs Dr. Fred Lubnow is giving a presentation on “The Monitoring and Management of Cyanotoxins in Raw Water Supplies.” We hope to see you there! 

LEARN MORE

 

October 12: Association of New Jersey Environmental Commissions (ANJEC) 2018 Environmental Congress

ANJEC, a nonprofit organization supporting efforts to protect the environment and preserve natural resources in communities throughout New Jersey, is hosting its 45th Annual Environmental Congress at Mercer County College. The Environmental Congress is an annual statewide gathering of environmental commissions, local officials, agencies, citizen groups and environmental organizations, which includes an exhibitors hall, farmer’s market, and workshops on a variety of current environmental topics. Princeton Hydro, a business member of the ANJEC, will be exhibiting during the event. Stop by the booth to say hello to Dr. Stephen J. Souza, Princeton Hydro Founder and ANJEC Board of Trustees member, and Dana Patterson, Communications Strategist for Princeton Hydro.

LEARN MORE & REGISTER

 

October 23 – 25: New Jersey Association for Floodplain Management (NJAFM) 14th Annual Conference

NJAFM is hosting its 14th Annual Conference and Exhibition in Atlantic City, NJ. Participants will attend meetings and seminars covering topics, including hazard mitigation, flood insurance, infrastructure, mapping, planning, flood modeling, regulations, floodproofing, stormwater management, flood proofing, construction standards and more. Princeton Hydro’s Christiana Pollack, GISP, CFM and NJDEP’s Jessica Jahre, PP, AICP, CFM are giving a presentation, titled “A Flood Assessment for the Future,” for which they’ll showcase a flood assessment and flood mitigation analysis that Princeton Hydro performed in the Lower Moodna Creek Watershed.

LEARN MORE & REGISTER

 

October 23: “Undamming the Hudson River” Film Screening and Panel Event, Free & Open the Public

Riverkeeper and Patagonia present the premiere of “Undamming the Hudson River,” a short documentary film by National Geographic filmmaker Jon Bowermaster showcasing Riverkeeper’s efforts to restore natural habitat by eliminating obsolete dams throughout the Hudson River Estuary. The screening will be followed by refreshments and a panel discussion, moderated by Bowermaster, featuring experts in the field and an audience Q&A. Panelists, include:

  • Laura Wildman, PE – Water Resources and Fisheries Engineer, Princeton Hydro
  • George Jackman – Habitat Restoration Manager, Riverkeeper
  • Gwen McDonald – Director of Green Projects, Save the Sound
  • Andy J. Danylchuk, PhD – Associate Professor of Fish Conservation, UMASS Amherst, and Patagonia Fly Fishing Ambassador

This event is free and open to the public and will take place at Patagonia SoHo, 72 Greene St, New York, NY 10012 from 7:30 – 10pm.

RSVP HERE

 

October 24: Mid-Atlantic Chapter of the Urban & Regional Information Systems Association (MAC URISA) 2018 Conference

MAC URISA 2018, the largest GIS conference in the Mid-Atlantic region, will showcase outstanding and innovative uses of GIS technologies in the area. The program includes a variety of presentations, breakout sessions, a GIS Techspo forum, lightening talks, and more. Thomas Hopper, Princeton Hydro’s GIS Analyst, is providing a technical demonstration on the Linkage Mapper GIS Toolkit, which was created by the Nature Conservancy to support habitat connectivity analyses.

LEARN MORE & REGISTER HERE

 

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

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

LEARN MORE

 

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

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

LEARN MORE & REGISTER

 

STAY TUNED FOR OUR NOVEMBER EVENT SPOTLIGHT!

Dam Removal Underway in Watertown, Connecticut

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

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

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

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

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

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

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

REMOVAL OF HEMINWAY POND DAM ON STEELE BROOK IN WATERTOWN UNDERWAY

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

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

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

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

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

 

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

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

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

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

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

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

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

 

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

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

 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Lowering New Pipe Into Place

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

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

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

 

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

 

 

 

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

Lithuania Hosts its First-Ever
Dam Removal Workshop

Princeton Hydro’s Laura Wildman Invited to Present

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

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

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

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

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

Presentations covered a wide variety of topics, including:

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

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

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

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

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

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

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

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

 

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.

New Book Aims to Protect and Restore Fish Migrations

Rivers are a critical natural resource and an essential element for the health and survival of billions of people and countless species. Flourishing populations of migratory fish are an important indicator of a healthy, coastally connected river and a robust aquatic ecosystem as a whole. Migratory fish help to maintain a balanced food web, support productive river systems, and provide income for people around the world.

Yet many migratory fish species are severely threatened primarily due to man-made obstacles like dams and weirs, which disrupt the natural flow of rivers and prevent fish migration. When fish can’t reach their habitat, they can’t reproduce and maintain their populations.

Photo Credit: “From Sea to Source 2.0”

A new book, titled From Sea to Source 2.0, explores the challenges that lie behind restoration of fish migration in rivers around the world and provides a practical guide to promoting the protection and restoration of fish migration. The book is a unique collaboration of over 100 international fisheries professionals and supported by river managers, governments, research institutes and NGOs including World Wildlife Fund and The Nature Conservancy. Geared toward practitioners, but also a wonderful resource for the general public, the book is comprised of inspiring stories from nearly every continent on the planet. Click here to download it for free.

“Ultimately our ambition is to contribute in a positive way to making a better world and a positive difference for migratory fish, nature and humans on local and global levels by inspiring new initiatives for and with people all around the world,” as stated on www.fromseatosource.com. “Whether the challenge is simply to increase access to spawning habitats through connectivity improvements for salmon, or to maintain the livelihoods for hundreds of millions of people dependent upon fish and fisheries in the great rivers of Asia, Africa and South America, we hoped our book would help to achieve these goals.”

Princeton Hydro’s Dam Removal Expert Laura Wildman, P.E. and Fluvial Geomorphologist Paul Woodworth are proud contributors to the book, helping to write the dam removal chapter, creating a dam removal flow chart for the book, and providing multiple photos utilized in the book. Princeton Hydro is also listed as a contributing sponsor.

“We’re so proud to be part of this incredible project with so many partners globally,” said Wildman. “We envision that this book will provide a valuable resource and inspiration for those in countries and regions where the importance of restoring riverine connectivity is newly gaining momentum. We hope it will help emphasize the importance of finding balanced and environmentally informed solutions when proposing additional utilization of public trust resources such as rivers.”

Approximately 40% of all fish species in the world reside in freshwater ecosystems, contributing economic and ecological benefits and value. It’s critical that we support efforts that aim to protect migratory fish species, reconnect rivers, sustain fish passage, and preserve free-flowing rivers through removing unnecessary dams, reconnecting floodplains, managing our water use, and managing hydropower for sustainable rivers.

Education and awareness building are key first steps in protecting rivers. From Sea to Source 2.0 seeks to inform, educate and inspire those who want to know more about how to meet the challenges of restoring fish migration in rivers around the world.  The book is regarded as a crucial resource in the ongoing fight to protect and preserve the enormous value of our waterways.

Get your free copy here.

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, visit: bit.ly/DamBarrier.

Conservation Spotlight: Restoring Fish Passage on the Noroton River

For thousands of years, river herring swam from the Atlantic Ocean through the Long Island Sound and up the Noroton River to spawn each spring. Then, they returned to the ocean until the next spawning season.

Back in the 1920s, President Dwight D. Eisenhower’s administration began connecting the country through a massive interstate highway system. As part of the infrastructure plan, hundreds of thousands of culverts were built across the U.S. with the intention of moving water quickly and efficiently. While that goal was met, many migratory fish and other aquatic organisms could not overcome the culverts’ high-velocity flows, shallow water depths, and perched outlets. This infrastructure prevented them from reaching their native migratory destinations.

By the late 1950s, Interstate 95 cut through Connecticut’s coastal rivers, and culverts were installed to convey river flows. Alewives, American Shad, Blueback Herring, and other native fish species were unable to navigate the culverts. Their populations dwindled to the point where Connecticut, along with Rhode Island, Massachusetts, and North Carolina, instituted moratoriums on catching and keeping the valued forage fish.

Along the Noroton River, three parallel concrete culverts, each 300-feet long, 13-feet wide and 7-feet in height were installed, completely blocking upstream fish passage.  In order to restore important fish populations and revitalize the Noroton River, Save the Sound launched a project that reopened approximately seven miles of the river, allowing migratory fish populations to safely and easily travel through the culverts to reach their original spawning habitat upstream.

The project is a collaboration among Save the Sound, Darien Land Trust, Connecticut Department of Energy and Environmental Protection (CTDEEP), Connecticut Department of Transportation, Princeton Hydro, and other partners. For the project, Princeton Hydro lead design engineering and guided the construction of the following elements to restore upstream fish passage:

  • The installation of a concrete weir at the upstream end of the culvert to increase water depths in one culvert during low-flow periods;
  • The installation of concrete baffles to reduce flow velocities and create resting places for fish, and;
  • The installation of a naturalized, step-pool, rock ramp at the downstream end of the project to allow fish to ascend into the culvert gradually, overcoming the two-foot vertical drop present under existing conditions. The rock ramp consists of a grouted riverstone base with large grouted boulders arranged to make steps, with low-flow passage channels, between a series of pools approximately 1-foot deep that create resting places for upstream migrating fish.

Reopening river passage for migratory species will improve not only the health of the Noroton River itself, but will also benefit the overall ecosystem of Long Island Sound. Over the last decade, fish passage projects around the sound’s Connecticut and New York shores have dramatically increased freshwater spawning habitat for the foundational species whose return is restoring a more vibrant food web to the Long Island Sound.

Construction of the baffles and rock ramp were completed in time for the 2018 migratory season. Construction of the concrete weir is on temporary hold for low-flow conditions. On April 26, 2018, project partners gathered for a project celebration and the release of migratory fish by CTDEEP at an upstream location.

“It’s fascinating to feel the change in the flow patterns against your legs as you walk through the baffled culvert knowing that it will now facilitate fish passage through this restored reach,” said Princeton Hydro’s New England Regional Office Director and Water Resources and Fisheries Engineer Laura Wildman, P.E. “It is a very attractive and natural-looking fishway, and we’re proud to have created a design that fits so well into the surrounding landscape.”

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, visit: bit.ly/DamBarrier.

UPCOMING EVENTS: SPRING UPDATE FROM PRINCETON HYDRO

Throughout April and May, Princeton Hydro is participating in a variety of events focused on conserving, restoring, and protecting our precious water resources.

April 11: New Jersey Invasive Species Strike Team 10th Annual Conference

Presented by the Friends of Hopewell Valley Open Space, the 10th Annual New Jersey Invasive Species Strike Team Conference is considered the most comprehensive state-wide forum on invasive species. The conference brings participants together to collaborate and address new and emerging invasive species issues from a state-wide perspective, and includes an exhibitor hall, networking opportunities and a variety of presentations and panel discussions on topics ranging from “Rare Bird Conservation” to “Foraging for Invasive Species” to “Herbicide Application Techniques.”

Princeton Hydro, a proud sponsor of the conference, will be exhibiting. We hope to see you there!

View the full conference schedule.

 

April 14: Musconetcong River Watershed Cleanup

As part of the 26th Annual Musconetcong River Cleanup on April 14th from 9 AM – 12 PM, Princeton Hydro will be leading a volunteer team at the Warren Glen Dam site. Friends and family welcome to join us!

For details, visit the Musconetcong Watershed Association’s event page.

 

April 18: The New England Chapter of the American Public Works Association Spring Conference

The New England Chapter of the American Public Works Association (NEAPWA) serves professionals in all aspects of public works and supports the people, agencies, and organizations that plan, build, maintain, and improve communities.

This year’s NEAPWA Spring Conference is being held at the Pratt & Whitney Stadium in East Hartford, CT. The conference includes a tour of the stadium, an exhibitor hall, educational session, and technical workshops on topics, like “Water System Infrastructure Planning in Response to Drought Conditions,” “Leveraging GIS Technology with Municipal LED Street Lights,” and “Using Infiltration and Inflow to Work Smarter not Harder.”

View the full conference agenda.

 

April 26: Arbor Day Planting and Bird Walk at Exton Park

We’re celebrating Arbor Day on April 26th (one day early) with Friends of Exton Park. First, we’ll be on the lookout for spring migrants during a morning bird walk (8:30 AM – 10:30 AM). Then, we’ll show our Arbor Day spirit by planting a variety of native plants at Exton Park (11:00 AM). We hope you’ll join us!

Click here to RSVP.

 

 

May 4: New York State Federation of Lake Associations Annual Conference

The New York State Federation of Lake Associations will host its 35th Annual Conference at the Fort William Henry Conference Center in Lake George, NY.  This year’s conference, which is titled, “Protecting Our Lakes for 35 Years – Our Past, Present and Future,” will feature a diverse exhibitor hall, networking opportunities, a silent auction and a variety of educational sessions. Princeton Hydro is exhibiting and giving five presentations:

  • Nutrient Inactivation: A Pennsylvania Case Study
  • You Have Your Lake Data, Now What? Creating a Watershed Plan
  • One Watershed, Many Lakes: A Strategic Plan for the Kettle Lakes of Southern Onondaga and Northern Cortland Counties
  • Proactive Management of Harmful Algal Blooms
  • Hydrilla Control in Harveys Lake, PA

Read more.