Efforts to Manage Hydrilla in Harveys Lake Prove Difficult but Effective

Collaboration between state agencies and local organizations in Luzerne County bring in grant money to determine Hydrilla infestation levels in Harveys Lake. Treatment efforts are scheduled for 2019.

Story provided by Princeton Hydro Senior Limnologist Michael Hartshorne, and originally published in the Pennsylvania iMapInvasives Fall 2018 Newsletter

Hydrilla (Hydrilla verticillata)

Hydrilla (Hydrilla verticillata) is a relatively new invasive plant in Pennsylvania with the first documented occurrence in 1989 in Adams County. Still, it was not until recently that lake managers, park rangers, and others in the natural resource field have turned their attention to this aggressive invader. Looking incredibly similar to our native waterweed (Elodea canadensis), hydrilla differs in that it is comprised of 4-8 whorled, toothed leaves in contrast to the smooth edged, 3-leaved whorl of E. canadensis.

 

Harveys Lake, located in the Borough of Harveys Lake (Luzerne County) is a large, deep glacial lake with limited littoral (i.e., shoreline) habitat. A significant body of work has been conducted at the lake with the original Phase I: Diagnostic-Feasibility Lake study conducted in 1992 and a Total Maximum Daily Load (TMDL) issued for phosphorus in 2002.

From 2002 to present, Princeton Hydro has assisted the Borough in the restoration of the lake with a heavy focus on stormwater best management practices (BMPs) supplemented by routine, in-lake water quality monitoring. The goal of the storm water/watershed-based efforts was to reduce the lake’s existing, annual total Hydrilla (Hydrilla verticillata) phosphorus load so it’s in full compliance with the established TMDL.

Mapped locations noted in 2014 and 2015 of hydrilla in Harveys Lake as documented in the Pennsylvania iMapInvasives database.

Over the last 15 years, the installation of these watershed-based projects has led to improved water quality conditions; specifically, phosphorus and algae concentrations have been reduced. While water quality conditions improved Harveys Lake, it was during one of the routine, summer water quality monitoring events conducted in July 2014 that a dense stand of hydrilla was noted at the Pennsylvania Fish and Boat Commission’s public boat launch. More than likely, the plant entered the lake as a “hitchhiker” on the boat or trailer being launched from this public boat launch by someone visiting the lake.

Hydrilla (Hydrilla verticillata) Credit: Nick Decker, DCNR Bureau of State Parks

Since the initial identification and confirmation of the hydrilla, the Borough of Harveys Lake has worked in conjunction with the Harveys Lake Environmental Advisory Council, the Luzerne County Conservation District, the Pennsylvania Department of Environmental Protection, and Princeton Hydro to secure funding for additional surveys to determine the spatial extent and density of growth followed by an aggressive eradication plan.

Grant funds already allocated to Harveys Lake under the state’s Non-Point Source Pollution Program were used to conduct a detailed boat-based and diving aquatic plant survey of Harveys Lake to delineate the distribution and relative abundance of the hydrilla in 2014. During these surveys, the distribution of the hydrilla was found to be limited to the northern portion of the lake with the heaviest densities just off the boat launch with plants observed growing in waters 20-25 feet deep.

A follow-up survey had shown hydrilla coverage to increase from 38% of surveyed sites to 58% of sites in 2016 with hydrilla now present at the lake’s outlet area. Spatial coverage of hydrilla increased from approximately 50 acres in 2014 to 210 acres in 2016, an increase of 160 acres.

This map shows the 2018 proposed treatment area of Harvey’s Lake. Due to funding issues, treatment is now scheduled for 2019. The current hydrilla distribution encompasses the entire littoral zone of Harvey’s Lake.

In hopes of preventing hydrilla escaping into the lake’s outlet stream, the Borough of Harveys Lake funded an emergency treatment of the two-acre outlet area in 2016 utilizing the systemic herbicide Sonar® (Fluridone). A follow-up treatment of 159 acres was conducted in 2017, again utilizing the Fluridone-based systemic herbicide.

The next treatment, which will attempt to cover the majority of the littoral habitat covered by hydrilla, is scheduled for late spring/early summer of 2019. It should be noted that Sonar® is being applied at a low concentration that is effective at eradicating the hydrilla, but will not negatively impact desirable native plant species.

The treatments conducted to date have documented some reductions in the vegetative coverage of hydrilla as well as tuber production relative to the original plant surveys conducted in 2016. However, it is recognized that it will take multiple years of treatment to eradicate this nuisance plant from the lake, as well as a highly proactive, interactive program to educate residents as well as visitors to the lake in preventing the re-introduction of this or other invasive species to Harveys Lake.

 

The successful, long-term improvement of a lake or pond requires a proactive management approach that addresses the beyond simply reacting to weed and algae growth and other symptoms of eutrophication. Our staff can design and implement holistic, ecologically-sound solutions for the most difficult weed and algae challenges. Visit our website to learn more about Princeton Hydro’s lake management services: http://bit.ly/pondlake

Michael Hartshorne‘s  primary areas of expertise include lake and stream diagnostic studies, TMDL development, watershed management, and small pond management and lake restoration. He is particularly skilled in all facets of water quality characterization, from field data collection to subsequent statistical analysis, modeling, technical reporting, and the selection and implementation of best management practices. He has extensive experience in utilizing water quality data in concert with statistical and modeling packages to support load reduction allocations for the achievement of water quality standards or tailored thresholds set forth to reduce the rate of cultural eutrophication. He also has significant experience in conducting detailed macrophyte, fishery, and benthic surveys.

Mitigation Milestone Reached at Mattawoman Creek Mitigation Site

Photo courtesy of GreenVest

Mattawoman Creek Mitigation Project will Restore and Protect 80+ Acres of Mattawoman Creek, Chesapeake Bay’s Most Productive Tributary

As one of the Chesapeake Bay’s most productive tributaries and a vital part of Maryland’s natural resources, Mattawoman Creek supports some of the largest populations of finfish, amphibians, and birds in the state. A collaborative team of private and public sector entities have designed the “Mattawoman Creek Mitigation Site” in Pomfret, Charles County, Maryland, an effort that will enhance or create 64+ acres of wetlands and restore nearly 3,800 linear feet of this perennial stream.  With over 28,500 native trees and shrubs to be planted, this mitigation project will result in 80+ acres of continuous, forested wetland with complex and diverse vegetative communities. It is expected to provide a wide array of habitat to resident and transient wildlife, including birds, reptiles, invertebrates, amphibians and rare, threatened and endangered species.

Unique to this project, Mattawoman Creek Mitigation Site is Maryland’s first-ever Umbrella Mitigation Banking Instrument (UMBI) for federal and other government agency use.   A UMBI is the bundling of multiple mitigation banks into one agreement in order to streamline the regulatory approval process, thereby eliminating steps and involving fewer resources. The Maryland UMBI document helps the USAF and other public agencies secure certainty of cost and schedule, facilitate timely permit issuance, and expedite the satisfaction of their permitted requirements for planned capital improvement projects. This approach also maximizes the scale of restoration and resulting land protection and efforts, creating contiguous blocks of habitat with greatly enhanced benefits compared to single, permittee-responsible projects. This precedent was a result of a partnership between United States Air Force (USAF) and Joint Base Andrews (JBA), U.S. Army Corps of Engineers (USACE), Maryland Department of the Environment (MDE), GreenTrust Alliance, GreenVest, and Princeton Hydro.

Projects completed under the UMBI will reduce federal and state workload expediting the regulatory review and issuance of permits by the MDE and USACE. Additionally, projects completed under this UMBI will aid in compliance with the Federal Paperwork Reduction Act where federal regulatory staff can evaluate success and performance issues for multiple permittees at one single habitat restoration or mitigation site. In addition, federal costs are capped, and liabilities  are transferred through to GreenVest, the private sector operator, and GreenTrust Alliance, the nonprofit bank sponsor, who will also serve as the long-term steward of sites restored under this program.

Pictured is the southern restoration area after
sorghum germination, prior to wetland creation
and reestablishment.
A function-based stream assessment was
performed on the degraded channel.

 

Photo courtesy of GreenVestDesign, engineering/modeling, and permitting of the site was completed by  Princeton Hydro and GreenVest under our currently Ecosystem Restoration contract with the USACE. Princeton Hydro also provided an Environmental Assessment and Environmental Baseline Survey, and conducted a geotechnical investigation, which included the advancement of test pits, visual and manual investigation techniques and logging, infiltration testing, laboratory soils testing, and seasonal high-water table estimations.

A wetland water budget was also developed for the proposed wetland creation and restoration to determine if sufficient water is available to establish or reestablish wetlands on the site. It was also used to inform design development including proposed grading and plant community composition. The establishment and re-establishment of wetlands on the site will be accomplished through directed grading, ditch plugging and stream restoration designed to maximize the retention of surface water, floodplain re-connection, and groundwater inputs.

Highlights from the Mattawoman Creek Wetland and Stream Mitigation project:
  • 80 acres of land were placed into conservation easement and removed from active row crop production and cattle pasture. The easement, which is held by GreenTrust Alliance, provides permanent protection for all 80 acres.
  • Over 64 acres of wetlands will be restored, created, enhanced or preserved, which will sequester approximately 75 tons of carbon per year.
  • 3,798 linear feet of perennial stream will be restored by re-establishing, historic floodplain access during more frequent storm events, stabilizing hydraulics and geomorphology, and adding aquatic habitat value.
  • Full integration of the wetland and stream restoration elements will occur exponentially, increasing anticipated functions and values in the post construction condition. Functions include: storm damage and flood attenuation, groundwater recharge and discharge, nutrient cycling and sequestration, local water quality improvement, and wildlife habitat enhancements.
  • This project will also create and enhance the forested wetland and stream habitat for the State-listed Threatened Selys’ Sundragon (Helocordulia selysii).
  • As part of the site design, over 28,500 native trees and shrubs will be planted.
  • The Mattawoman Creek Mitigation Site is located within a Tier 3 Biodiversity Conservation Network area. These areas are classified by the Department of Natural Resources as “highly significant for biodiversity conservation” and are priority conservation areas that support critical species and habitats.
  • The project will yield advanced mitigation values: 7.913 in wetland credits and 1,595 in stream credits. These credits are durable and will be available for JBA’s use in order to satisfy permitted impacts associated with planned capital improvement projects.

Over 6,000 acres (25%) of the Mattawoman Creek watershed has been protected by public ownership and various conservation and agricultural easements, which, in addition to the Mattawoman Creek Mitigation Site, help ensure that Mattawoman Creek forever remains a high-quality destination for outdoor recreation.

Princeton Hydro specializes in the planning, design, permitting, implementing, and maintenance of tidal and freshwater wetland rehabilitation projects. To learn more about our wetland restoration, creation, and enhancement services, visit: http://bit.ly/PHwetland

Princeton Hydro Joins American Sustainable Business Council

Princeton Hydro is proud to join the American Sustainable Business Council (ASBC), a coalition of businesses that prioritizes, “a triple bottom line of People, Planet, and Profit.” ASBC works to combat climate change by divesting from fossil fuels and investing in climate solutions, and passing carbon tax legislature at both federal and state levels. ASBC also works to address many other issues related to public health and the economy.

As a sustainable business headquartered in New Jersey, Princeton Hydro is also affiliated with the New Jersey Sustainable Business Council, the state chapter of the ASBC. In addition to joining the councils, Princeton Hydro’s President, Geoffrey Goll, P.E. joined the steering committee for ASBC’s “Clean Water is Good for Business” campaign.

“At Princeton Hydro, we are passionate about the protection of natural resources, fostering stewardship, and designing and conducting business in a sustainable manner. We believe in affecting positive change in our world for people and the environment,” said Goll. “We’re excited to align ourselves with an organization that reflects our core values, and we look forward to future sustainable business opportunities.”

The Clean Water is Good for Business campaign focuses on the Delaware River Watershed, a region that Princeton Hydro is actively working to protect and enhance. The campaign focuses on the importance of clean water, not just for human health, but for business health as well. Even companies that don’t directly rely on clean water for production of goods still need it to sustain day-to-day functions and keep employees healthy. ASBC recently released its Business Case where it lists the top priorities of the campaign as creating a comprehensive strategy, growing funding for conservation, and decreasing stormwater runoff.

Clean water is not only the key foundation to life itself, but a sustainable economy as well. Without clean water, we put our natural resources, businesses, and communities at risk. Protecting water quality is a long-term effort that requires continued investment, monitoring, and evaluation.

Princeton Hydro offers expertise in water resources management and engineering, ecosystems, and geotechnical investigations and design. Our staff provides a full suite of services throughout the Mid-Atlantic and New England states. Our capabilities are reflected in our award-winning projects that consistently produce real-world, cost-effective solutions. If you’re interested in learning how Princeton Hydro can help you, please contact us.

Innovative and Effective Approach to Wetland Restoration

The Pin Oak Forest Conservation Area is a 97-acre tract of open space that contains an extremely valuable wetland complex at the headwaters of Woodbridge Creek. The site is located in a heavily developed landscape of northern Middlesex County and is surrounded by industrial, commercial, and residential development. As such, the area suffered from wetland and stream channel degradation, habitat fragmentation, decreased biodiversity due to invasive species, and ecological impairment. The site was viewed as one of only a few large-scale freshwater wetland restoration opportunities remaining in this highly developed region of New Jersey.

Recognizing the unique qualities and great potential for rehabilitating and enhancing ecological function on this county-owned parkland, a dynamic partnership between government agencies, NGOs, and private industry, was formed to restore the natural function of the wetlands complex, transform the Pin Oak Forest site into thriving habitat teeming with wildlife, and steward this property back to life. The team designed a restoration plan that converted 28.94 acres of degraded freshwater wetlands, 0.33 acres of disturbed uplands dominated by invasive species, and 1,018 linear feet of degraded or channelized streams into a species-rich and highly functional headwater wetland complex.

BEFORE
View of stream restoration area upon commencement of excavation activities. View of containerized plant material staged prior to installation.

 

We used an innovative approach to restore the hydraulic connection of the stream channel with its floodplain in order to support wetland enhancement. Additionally, to further enhance wetlands with hydrologic uplift, the team incorporated microtopography techniques, which creates a variable surface that increases groundwater infiltration and niches that support multiple habitat communities. This resulted in a spectrum of wetland and stream habitats, including the establishment of a functional system of floodplain forest, scrub shrub, emergent wetlands and open water. Biodiversity was also increased through invasive species management, which opened the door for establishing key native flora such as red maple, pin oak, swamp white oak, and swamp rose. The restored headwater wetland system also provides stormwater quality management, floodplain storage, enhanced groundwater recharge onsite, and surface water flows to Woodbridge Creek.

Completed in 2017, the integrated complex of various wetland and upland communities continues to provide high quality habitat for a wide variety of wildlife species including the state-threatened Black-crowned Night heron and Red-headed Woodpecker. The work done at the site significantly enhanced ecological function, providing high-quality habitat on indefinitely-preserved public lands that offer countless benefits to both wildlife and the community.

AFTER
Post-restoration in 2018, looking Northeast. View of wetland enhancement approximately 2 months after completion of seeding and planting activities.

 

Public and private partnerships were and continue to be critical to the success of this project. The diverse partnership includes Middlesex County Office of Parks and Recreation, Woodbridge Township, Woodbridge River Watch, New Jersey Freshwater Wetlands Mitigation Council, GreenTrust Alliance, GreenVest, and Princeton Hydro. The partners joined together as stakeholders to identify long term restoration and stewardship goals for Pin Oak Forest Preserve, and nearly four years later, the partners all remain involved in various aspects of managing the property and this project itself, ranging from fiscal oversight by New Jersey Freshwater Wetland Mitigation Council and GreenTrust Alliance, to permit and landowner access coordination performed by Woodbridge Township and Middlesex County, or the ongoing stewardship, maintenance, and monitoring of the project and the larger park, being conducted by being conducted by GreenTrust Alliance, GreenVest, and NJ Department of Environmental Protection.

This project was funded through the New Jersey Freshwater Wetland In-Lieu Fee program. In 2014, GreenTrust Alliance, GreenVest, and Princeton Hydro secured $3.8 million dollars of funding on behalf of the Middlesex County Parks Department to restore three wetland sites, which included Pin Oak Forest.

The Pin Oak Forest project is a great model for showcasing a successful approach to the enhancement of public lands through a dynamic multidisciplinary, multi-stakeholder partnership. And, because of proper planning and design, it has become a thriving wildlife oasis tucked in the middle of a densely-populated suburban landscape.

Princeton Hydro specializes in the planning, design, permitting, implementing, and maintenance of wetland rehabilitation projects. To learn more about our wetland restoration, creation, and enhancement services, visit: bit.ly/PHwetland

Restoring and Revitalizing Freshwater Mussels

Freshwater mussels are among the oldest living and second most diverse organisms on Earth with over 1,000 recognized species. Here in the eastern part of the U.S., we have more species of freshwater mussels than anywhere in the world. Unfortunately, freshwater mussels are one of the most rapidly declining animal groups in North America. Out of the 300 species and subspecies found on the continent, 70 (23%) have been federally listed as “Threatened” or “Endangered” under the Endangered Species Act. And, in the last century, over 30 species have become permanently extinct. So, why are populations declining so fast?

Freshwater mussels are filter feeders and process large volumes of the water they live in to obtain food. This means of survival also makes them highly susceptible to industrial and agricultural water pollution.  Because they are constantly filtering water, the contaminants and pathogens that are present are absorbed into the mussel’s tissues. As such, mussels are good indicators of water quality and can greatly contribute to improving water quality by filtering algae, bacteria and organic matter from the water column.

Not only do freshwater mussels rely on water quality, they are dependent on fish and other aquatic organisms for reproductive success. In order for a freshwater mussel to complete the reproduction process, it must “infect” a host fish with its larvae. The method depends on the specie of mussel. Some species lure fish using highly modified and evolved appendages that mimic prey. When a fish goes into investigate the lures, the female mussel releases fertilized eggs that attach to the fish, becoming temporarily parasitic. Once the host fish is infected, it can transfer the mussel larvae upstream and into new areas of the river.

Both habitat loss from dam construction and the introduction of pesticides into the water supply has contributed to the decline of freshwater mussels. With approximately 300 mussel species in the U.S. alone, a critical component of restoring and revitalizing mussel populations is truly understanding their biology, which begins with the ability to properly differentiate each species and properly identify and catalog them. Princeton Hydro’s Senior Scientist Evan Kwityn, CLP and Aquatic Ecologist Jesse Smith recently completed the U.S. Fish and Wildlife Service‘s Fresh Water Mussel Identification Training at the National Conservation Training Center in West Virginia.

Through hands-on laboratory training, Evan and Jesse developed their freshwater mussel identification skills and their knowledge of freshwater mussel species biology. Course participants were tasked with mastering approximately 100 of the most common freshwater mussel species in the United States. They also learned about proper freshwater mussel collection labeling, the internal and external anatomy and meristics of a freshwater mussel, and distributional maps as an aid to freshwater mussel identification.

In a recently published press release, Tierra Curry, a senior scientist with the Center for Biological Diversity was quoted as saying, “The health of freshwater mussels directly reflects river health, so protecting the places where these mussels live will help all of us who rely on clean water. This is especially important now, when we see growing threats to clean water from climate change, agriculture and other sources.”

Princeton Hydro is committed to protecting water quality, restoring habitats, and managing natural resources. Read about some of our recent projects and contact us to discuss how we can help you.

To learn more about freshwater mussels, check out this video from U.S. Fish and Wildlife Service:

UPDATE: The Columbia Dam Is Coming Down

It’s happening! The Columbia Dam on the Paulins Kill in Northern New Jersey is finally coming down thanks to a successful collaboration between The Nature Conservancy, American Rivers, U.S. Fish and Wildlife Service, NJDEP Division of Fish and Wildlife Service, and Princeton Hydro. The first cut on the main dam wall was made just two weeks ago, and the water has started flowing downstream as the concrete is slowly being removed by the contractors RiverLogic Solutions and SumCo Eco-Contracting.

“In New Jersey, successful dam removal projects are often the result of partnerships between nonprofit organizations, federal and state agencies, consultants, and others working together toward the common goal of river restoration,” exclaimed Dr. Laura Craig, Director of River Restoration, American Rivers. “The first day of dam demolition is always a joyous occasion for project partners, but I was especially happy to see the river flowing through the breached Columbia Dam for the first time after working so intensely on this project for the last few years.”

Princeton Hydro has been involved with the engineering and restoration design from the beginning, so we’re very excited to report on this major update.  Our team of engineers and ecologists studied the feasibility of removal as requested by American Rivers in partnership with the New Jersey chapter of The Nature Conservancy.  We investigated, designed, and prepared the necessary permits for the removal of this dam. And, now we’ve been subsequently been hired to provide construction administration services during the removal process, which means we get to see the dam come down firsthand, piece by piece!

“It is truly amazing and exciting to finally see the main and remnant dams come down, as I have been involved in this restoration effort since the feasibility stage,” said Kelly Klein, Senior Project Manager, Princeton Hydro. “I am so honored to be part of this dynamic team and to collaborate with our project partners during every stage of this dam removal.”

Geoff Goll, Princeton Hydro and Beth Styler Barry, The Nature Conservancy on site August 3, 2018. Photo credit: Laura Craig, American Rivers

“On Friday, August 3rd 2018, we began demolition of the 300 foot-long, 18 foot-high Columbia Dam. The Paulins Kill will run freely to meet the Delaware River for the first time in 109 years,” said New Jersey Nature Conservancy’s Beth Styler Barry. “The benefits of reconnecting these two freshwater ecosystems will be immediate and impact creatures that live in and near the stream, as well as people who come out to paddle, fish or enjoy the wildlife. Dam Removal projects are exciting, ecologically important and also a challenge, this project is a good example of partners coming together to get a great restoration project done.”

Because this is a big deal, we want to keep *YOU* updated on what’s happening from the field. Moving forward, we’ll post weekly blogs with scenes from the site.  Here’s a snapshot of what’s been happening over the last last two weeks:

August 1, 2018. Photo credit: Casey Schrading, Princeton Hydro

In order to make the first saw cut into the dam, Princeton Hydro and RiverLogic Solutions first identified the locations of the drill holes. These drill holes are used to feed the diamond wire through the dam for saw cutting.

August 1, 2018. Photo credit: Casey Schrading, Princeton Hydro

The crew placed the saw cutter machine on the staging area on top of the apron and prepared for the cut.

August 3, 2018. Photo credit: Princeton Hydro

In order to create a notch in the dam, the crew supplemented the saw cutting with hammering.

August 3, 2018. Photo Credit: The Nature Conservancy, Columbia Dam Volunteer Drone Team

August 3, 2018. Photo credit: Erik Sildorff, Delaware Riverkeeper Network

August 7, 2018. Photo credit: Casey Schrading, Princeton Hydro

Since the high water level was now higher than the bottom of the breach, water is able to flow in and over the notched section.

August 14, 2018. Photo credit: RiverLogic Solutions

Because of high flows of water from recent storm events, the dam breach is being widened to allow for larger flows of water to move downstream during high flow events. 

Additionally, a few weeks ago we reported on the lowering of the water levels and removal of the remnant dam downstream (below).

PHOTOS: Columbia Dam Removal

Since then, the remnant dam has been completed removed and the area has been stabilized.

July 23, 2018. Photo credit: Casey Schrading, Princeton Hydro

Now, the water can freely flow through this section of the Paulins Kill.

And, in case you missed it, we celebrated the commencement of the Columbia Dam removal with NJDEP’s Commissioner Catherine McCabe and our project partners. Full story below:

Celebrating the Columbia Dam Removal

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

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.

 

Conservation Spotlight: Dunes at Shoal Harbor Shoreline Protection

Hurricane Sandy was the largest storm to ever originate in the Atlantic ocean. It badly damaged several countries in the Caribbean, caused over $50 billion in damages along the Eastern Seaboard, and left dozens dead. While hurricanes are a natural part of our climate system, research shows that intense hurricane activity has been on the rise in the North Atlantic since the 1970s. This trend is likely to be exacerbated by sea level rise and growing populations along coastlines. Natural coastal habitats — like wetlands and dunes — have proven to shield people from storms and sea-level rise, and have protected coastal communities from hundreds of millions of dollars in damage.

The Dunes at Shoal Harbor, a residential community in Monmouth County, New Jersey, is situated adjacent to both the Raritan Bay and the New York City Ferry channel. The site, previously utilized for industrial purposes, consisted of a partially demolished docking/berthing facility. A significantly undersized 6” diameter, 8-foot long stone revetment was also constructed on the property.

During Hurricane Sandy, the revetment failed and the community was subjected to direct wave attack and flooding. Homes were damaged, beach access was impaired, and the existing site-wide stormwater management basin and outfall was completely destroyed.

Princeton Hydro performed a wave attack analysis commensurate with a category three hurricane event, and used that data to complete a site design for shoreline protection. Consistent with the analysis, the site design includes the installation of a 15-foot rock revetment (one foot above the 100-year floodplain elevation) constructed with four-foot diameter boulders. The project also consists of replacing a failed elevated timber walkway with a concrete slab-on-grade walkway, restoring portions of the existing bulkhead, clearing invasive plants, and the complete restoration of the failed stormwater basin and outlet.

A rendering of the “Dunes at Shoal Harbor” shoreline protection design by Princeton Hydro.

The plan incorporates natural barriers to reduce the impacts of storm surges and protect the coastal community, including planting stabilizing coastal vegetation to prevent erosion and installing fencing along the dune to facilitate natural dune growth.

These measures will discourage future erosion of the shoreline, protect the residential community from future wave attacks and flooding, and create a stable habitat for native and migratory species.  The project is currently in the permitting phase, and will move to construction when all permits are obtained from local, state, and federal agencies.

This project is an great example of Princeton Hydro’s ability to coordinate multi-disciplinary projects in-house. Our Water Resources Engineering, Geosciences Engineering, and Natural Resources teams have collaborated efficiently to analyze, design, and permit this shoreline protection project. For more information on our engineering services, go here.

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

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

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

Let’s dive in!

Benefits of a Healthy Fishery

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

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

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

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

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

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

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

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

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

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

Floating Wetland Island

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

Stocking Your Lake

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

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

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

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

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

In Summary

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

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

Learn More

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

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

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

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

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

 

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.