Protecting Greenwood Lake’s Water Quality Through Stormwater Management

The summer is upon us and Lakes Appreciation Month is right around the corner, what better time to pay a visit to and learn more about the lakes in your area.

Princeton Hydro conducts work on lakes throughout the Northeast to preserve, protect and improve water quality and ecological health, ensuring that your community lakes can be enjoyed now and into the future. Today, we’re putting the spotlight on Greenwood Lake:

Greenwood Lake, a 7-mile-long interstate lake that straddles the border of New York and New Jersey, is a popular recreation spot for residents and tourists of both states. Considered to be one of the top bass fishing lakes in New Jersey, Greenwood Lake is abundant with largemouth and smallmouth bass, yellow perch, chain pickerel and catfish. The lake is also extensively used by residents for swimming and boating.

For over 35 years, Princeton Hydro’s scientists have worked with New Jersey, local governing municipalities, and the various environmental organizations involved with the protection of Greenwood Lake and its watershed. In the early 2000s, we developed a comprehensive Restoration Plan and a proactive monitoring program that we have used over the years to properly manage the lake and its watershed. The plan was developed for the Greenwood Lake Commission and the Township of West Milford with funding provided through the New Jersey Department of Environmental Protection’s Nonpoint Source 319(h) Program. The Restoration Plan focuses heavily on the implementation of various types of stormwater best management practices (BMPs) to help reduce the influx of sediment and nutrients into the lake. We track the positive effects and benefits achieved through these stormwater projects by conducting both storm-event based and in-lake water quality monitoring.

The goal of the stormwater-based efforts is to ensure the lake’s total phosphorus (TP) load is systematically reduced in accordance with the lake’s established Total Maximum Daily Load (TMDL). The TMDL is a regulatory term in the U.S. Clean Water Act, that identifies the maximum amount of a pollutant (in this case phosphorus) that a waterbody can receive while still meeting water quality standards. Princeton Hydro was instrumental in developing the TMDL for Greenwood Lake. Phosphorus entering the lake from runoff is the primary driver of the lake’s eutrophication. The direct results of eutrophication are increases in the density of aquatic plants and nuisance algae. All this added productivity leads to reduced clarity, reductions in dissolved oxygen concentrations, and a number of other ecological impacts that compromise the quality, aesthetics, and use of the lake.

Last year, Princeton Hydro and the Greenwood Lake Commission, with input from the West Milford Environmental Commission, proposed an updated Watershed Implementation Plan (WIP) for the lake. Approved and funded by the NJ Highlands Council, the updated WIP includes a variety of components that build upon the original Restoration Plan and incorporate newly advanced stormwater management and Nonpoint Source Pollution (NPS) reduction technologies.

Belcher's Creek at Edgecumb and Glencross

The WIP includes in‐lake and stream monitoring; the assessment of the existing stormwater structures installed through grant‐based, watershed activities; and the identification of watershed-based projects that can be completed to support the Lake’s compliance with TMDL TP levels with a specific focus on the stormwater runoff produced by Belcher’s Creek, a major tributary to Greenwood Lake.

The WIP also includes the following nine minimum elements considered necessary by both NJDEP and USEPA for funding eligibility:

  1. Identify causes and sources of pollution
  2. Estimate pollutant loading into the watershed and the expected load reductions
  3. Describe management measures that will achieve load reductions and targeted critical areas
  4. Estimate amounts of technical and financial assistance and the relevant authorities needed to implement the plan
  5. Develop an information/education component
  6. Develop a project schedule
  7. Describe the interim, measurable milestones
  8. Identify indicators to measure progress
  9. Develop a monitoring component

While many of these elements have been indirectly addressed to varying degrees in the original Restoration Plan, in order to maximize Greenwood Lake’s opportunities to obtain State and Federal funding for the design and implementation of watershed control measures, the WIP now explicitly correlates the nine elements to eight specific deliverables, which are as follows:

  1. Conduct a detailed in‐lake and watershed‐based water quality monitoring program and compare the data to that collected in 2004 and 2005 to document changes or shifts in water quality.
  2. Meet with the Township of West Milford, Passaic County and other stakeholders to
    inventory recently completed BMPs and other watershed management measures.
  3. Conduct a field‐based evaluation of the stormwater project completed since the original 319‐grant funded Restoration Plan.
  4. Conduct site assessments to identify other potential stormwater/watershed BMP projects.
  5. Conduct a field assessment of the Belchers Creek Corridor to identify potential Nonpoint Source Pollution Reduction Projects.
  6. Assemble the WIP with all the 9 elements fully satisfied.
  7. Schedule and implement stakeholder and public meetings to evaluate project status.
  8. Submit of final version of WIP to the NJDEP and present the findings and recommendations to the public.

This project was initiated in September 2018 and is projected for completion by September 2019. The Greenwood Lake Commission, serves as the inter‐State steward of the Greenwood Lake watershed, and is working closely with Princeton Hydro and the watershed stakeholders (Township of West Milford, Passaic County and others), to ensure the WIP is a holistic document.

Stay tuned for more Greenwood Lake updates as the WIP progresses. For more information about Princeton Hydro’s lake management projects and capabilities, or to discuss your project needs and goals, please contact us.

Some of the photos utilized in this blog are from The Village of Greenwood Lake.

Arbor Day Bird Walk & Planting at Exton Park

On Thursday, April 25th, 2019, we teamed with the Friends of Exton Park and Homenet Automotive to host an early Arbor Day celebration at Exton Park in Exton, Pennsylvania. Paired with Bring Our Daughters and Sons to Work Day, the event drew over 35 volunteers (of all sizes) to help clean up Exton Park and plant 18 trees!

The day started with a leisurely bird walk throughout the park lead by Friends of Exton Park birders. Participants spotted Red-winged Blackbirds, a Solitary Sandpiper, a Wilson’s Snipe, a Downy Woodpecker and even a Green Heron.

After the bird walk, planting and clearing began. Together, volunteers cleared a hefty amount of multiflora rose and garlic mustard, two invasive species prevalent in the park. With the help of our Landscape Designer, Cory Speroff, MLA, ASLA, CBLP, and Senior Limnologist, Mike Hartshorne, volunteers also planted eight river birch, five red osier dogwood, and five swamp white oak trees throughout the park.

At Princeton Hydro, we value working with our clients and partners to create sustainable landscapes that include native plants that will thrive in our local ecosystems. At all our project sites, we aim to restore and maintain our natural habitats and landscapes. And, we love using teamwork to do it!

We were proud contribute the trees for this event and thank our volunteers for all their hard work. This is the second year we have participated in this Arbor Day volunteer event. We are looking forward to making it an annual tradition!

Friends of Exton Park offers weekly bird walks and volunteer opportunities throughout the year. Go here to learn more and get involved.

6 Tips To Prepare Your Pond For Spring

It’s officially time to say goodbye to winter and “spring” your pond out of hibernation mode. We’ve put together six tips for getting your pond ready for Spring and ensuring it remains healthy all year long.

1. SPRING CLEANING 

The first step in preparing your pond for Spring is to give it a thorough cleaning. Remove leaves, debris, and any surface algae that may have accumulated over the winter. For shallow ponds, you may be able to use a net or pond rake to remove debris and sediment from the bottom and along the perimeter of the pond.

2. INSPECT YOUR POND FOR DAMAGE

Inspect your pond, including berms, outlet structures, and trash racks for any damage that may have occurred over winter due to ice. If you observe any damage, we recommend contacting a professional right away. One of our engineers or certified pond managers can determine if the damage is superficial or requires more significant repairs. Also, if your pond is equipped with an aeration system, before starting it up, be sure to schedule a system inspection. A thorough inspection and proper start-up procedure will ensure the system remains fully and effectively operational for the entire summer.

3. PUT YOUR POND TO THE TEST

The routine testing of your pond’s water quality is an important part of preventing harmful algae growth, fish kills, and other problems. We recommend conducting a “Spring start up” water quality analysis of your pond. The resulting data will inform the management process and allow for the development of a pro-active, eco-friendly management plan. Maintaining your pond’s water quality helps to control nuisance aquatic species and promote environmental conditions supportive of a healthy and productive fishery.

4. AQUASCAPE YOUR SHORELINE

It’s important to check the pond’s shoreline for any signs of erosion. Mowing to the water line, especially in ponds that have fluctuating water levels, can lead to severe shoreline erosion. Eroding shorelines can be easily stabilized by planting native, riparian plants.

Deep-rooted, native emergent aquatic vegetation is able to tolerate alternating periods of exposure and dry inundation. The correct combination of native aquatic plants, emergent wetland plants, and transitional upland plants can correct or prevent chronic shoreline erosion problems. A properly planted (aquascaped) edge beautifies the shoreline, stabilizes erosion problems, creates fish and amphibian habitat, attracts pollinating species and a variety of birds, and decreases mosquito breeding.

5. CONSIDER INSTALLING AN AERATION SYSTEM

Sub-surface aeration systems eliminate stagnant water and keep your pond thoroughly mixed and properly circulated. These systems are the most cost-effective and energy-efficient way to maintain proper pond circulation. Proper aeration enhances fish habitat, minimizes the occurrence of algae blooms, and prevents mosquito breeding. It’s best to contact a certified lake/pond manager to first determine if aeration is the right solution for you. If it is, an aeration system tailored to your pond’s needs can be designed and installed.

6. HAVE AN ECOLOGICALLY BALANCED POND MANAGEMENT PLAN

There is more to pond management than weed and algae treatments alone. There is also a big difference between simple pond maintenance and ecologically-based pond management. A customized pond management plan acts as a “blueprint” that guides  proactive, long-term care for your pond.

Our certified lake and pond managers can assess the status of your pond and provide you with an environmentally holistic management plan that is based on the unique physical, hydrologic, chemical, and biological attributes of your pond. A management plan identifies the causes of your pond’s problems and provides you with the guidance needed to correct these problems. The results are far more environmentally sustainable than simple (and often unnecessary) reactive weed and algae treatments.

 

To learn more about our lake and pond management services or schedule a consultation, visit: http://bit.ly/pondlake.

Study Data Leads to Healthier Wreck Pond Ecosystem

Wreck Pond is a tidal pond located on the coast of the Atlantic Ocean in southern Monmouth County, New Jersey. The 73-acre pond, which was originally connected to the sea by a small and shifting inlet, got its name in the 1800s due to the numerous shipwrecks that occurred at the mouth of the inlet. The Sea Girt Lighthouse was built to prevent such accidents. In the 1930s, the inlet was filled in and an outfall pipe was installed, thus creating Wreck Pond. The outfall pipe allowed limited tidal exchange between Wreck Pond and the Atlantic Ocean.

In the 1960s, Wreck Pond flourished with wildlife and was a popular destination for recreational activities with tourists coming to the area mainly from New York City and western New Jersey. In the early spring, hundreds of river herring would migrate into Wreck Pond, travelling up its tributaries — Wreck Pond Brook, Hurleys Pond Brook and Hannabrand Brook — to spawn. During the summer, the pond was bustling with recreational activities like swimming, fishing, and sailing.

Over time, however, the combination of restricted tidal flow and pollution, attributable to increased development of the watershed, led to a number of environmental issues within the watershed, including impaired water quality, reduced fish populations, and flooding.

Throughout the Wreck Pond watershed, high stream velocities during flood conditions have caused the destabilization and erosion of stream banks, which has resulted in the loss of riparian vegetation and filling of wetlands. Discharge from Wreck Pond during heavy rains conveys nonpoint source pollutants that negatively impact nearby Spring Lake and Sea Girt beaches resulting in beach closings due to elevated bacteria counts. Watershed erosion and sediment transported with stormwater runoff has also contributed to excessive amounts of sedimentation and accumulations of settled sediment, not only within Wreck Pond, but at the outfall pipe as well. This sediment further impeded tidal flushing and the passage of anadromous fish into and out of Wreck Pond.

In 2012, Hurricane Sandy caused wide-spread destruction throughout New Jersey and the entire eastern seaboard. The storm event also caused a major breach of the Wreck Pond watershed’s dune beach system and failure of the outfall pipe. The breach formed a natural inlet next to the outfall pipe, recreating the connection to the Atlantic Ocean that once existed. This was the first time the inlet had been open since the 1930s, and the reopening cast a new light on the benefits of additional flow between the pond and the ocean.

Hurricane Sandy sparked a renewed interest in reducing flooding impacts throughout the watershed, including efforts to restore the water quality and ecology of Wreck Pond. The breach caused by Hurricane Sandy was not stable, and the inlet began to rapidly close due to the deposition of beach sand and the discharge of sediment from Wreck Pond and its watershed.

Princeton Hydro and HDR generated the data used to support the goals of the feasibility study through a USACE-approved model of Wreck Pond that examined the dynamics of Wreck Pond along with the water bodies directly upland, the watershed, and the offshore waters in the immediate vicinity of the ocean outfall. The model was calibrated and verified using available “normalized” tide data. Neighboring Deal Lake, which is also tidally connected to the ocean by a similar outfall pipe, was used as the “reference” waterbody. The Wreck Pond System model evaluated the hydraulic characteristics of Wreck Pond with and without the modified outfall pipe, computed pollutant inputs from the surrounding watershed, and predicted Wreck Pond’s water quality and ecological response. The calibrated model was also used to investigate the effects and longevity of dredging and other waterway feature modifications.

As part of the study, Princeton Hydro and HDR completed hazardous, toxic, and radioactive waste (HTRW) and geotechnical investigations of Wreck Pond’s sediment to assess potential flood damage reduction and ecological restoration efforts of the waterbody. The investigation included the progression of 10 sediment borings conducted within the main body of Wreck Pond, as well as primary tributaries to the pond. The borings, conducted under the supervision of our geotechnical staff, were progressed through the surgical accumulated sediment, not the underlying parent material. Samples were collected for analysis by Princeton Hydro’s AMRL-accredited (AASHTO Materials Reference Library) and USACE-certified laboratory. In accordance with NJDEP requirements, sediment samples were also forwarded to a subcontracted analytical laboratory for analysis of potential nonpoint source pollutants.

In the geotechnical laboratory, the samples were subjected to geotechnical indexing tests, including grain size, organic content, moisture content, and plasticity/liquid limits. For soil strength parameters, the in-field Standard Penetration Test (SPT), as well as laboratory unconfined compression tests, were performed on a clay sample to provide parameters for slope stability modeling.

The culvert construction and sediment dredging were completed at the end of 2016. Continued restoration efforts, informed and directed by the data developed through Princeton Hydro’s feasibility study, are helping to reduce the risk of flooding to surrounding Wreck Pond communities, increase connectivity between the pond and ocean, and improve water quality. The overall result is a healthier, more diverse, and more resilient Wreck Pond ecosystem.

During the time of the progression of study by the USACE, the American Littoral Society and the towns of Spring Lake and Sea Girt were also progressing their own restoration effort and completed the implementation of an additional culvert to the Atlantic Ocean.  The American Littoral Society was able to utilize the data, analysis, and modeling results developed by the USACE to ensure the additional culvert would increase tidal flushing and look to future restoration projects within Wreck Pond.

American Littoral Society

 

To learn more about our geotechnical engineering services, click here.

Urban Wetland Restoration to Yield Flood Protection for Bloomfield Residents

As part of the Third River Floodplain Wetland Enhancement Project,
a disturbed, flood-prone industrial site will be converted into a thriving public park.

Along the Third River and Spring Brook, two freshwater tributaries of the Passaic River, a disturbed industrial site is being transformed into 4.2 acres of wetlands, restoring the natural floodplain connection, enhancing aquatic habitat, and increasing flood storage capacity for urban stormwater runoff. The groundbreaking ceremony for this important ecological restoration project for Bloomfield Township took place last month.

“The Third River Floodplain Wetland Enhancement Project is a unique, creative solution that will transform a highly-disturbed, flood-prone, former industrial site into a thriving public park allowing for both passive and active recreational activities,” said Mark Gallagher, Vice President of Princeton Hydro. “By removing a little over four acres of upland historic fill in this densely developed area and converting it to a functioning floodplain wetland, the project will restore valuable ecological functions, increase flood storage capacity, and enhance wildlife habitat.”

Princeton Hydro is serving as the ecological engineer to Bloomfield Township for the Third River Floodplain Wetland Enhancement Project. Princeton Hydro’s scientists and engineers have assisted in obtaining grants, collected background ecological data through field sampling and surveying, created a water budget, completed all necessary permitting, and designed both the conceptual and final restoration plans. Additionally, Princeton Hydro will be conducting construction oversight during the implementation of this important urban wetland creation project.

The site includes 1,360 feet along the east bank of the Third River and 3,040 feet along the banks of the Spring Brook. These waterways are freshwater tributaries of the Passaic River and share a history of flooding above the site’s 100-year flood plain. The Third River, like many urban streams, tends to be the victim of excessive volume and is subjected to erosion and chronic, uncontrolled flooding. This green infrastructure project will re-establish the natural floodplain wetland and riparian plant communities, which will lead to a species-rich forest community through the removal of invasive species, setting the stage for native plants.

“Over 500 trees and shrubs will be planted in the new wetland with additional trees and shrubs being planted along Lion Gate Drive and in existing woodlands. The selected native plant species all provide important wildlife value such as providing fruit for migratory birds,” Gallagher explained. “We are excited to work with Bloomfield Township to design an urban restoration project that will both enhance the site’s ecological and flood storage value and provide accessibility to the community of Bloomfield.”

It is estimated that Phase One of the project, which includes the wetland construction and plantings, will be completed by September 1, 2019. The maintenance building, concession stand, ball field, etc., will be constructed as part of Phase Two.

“We are very excited to break ground on this exciting project that will have tremendous public benefits, like providing much-needed open space and lowering flood insurance rates for nearby residents and businesses,” said Bloomfield Township Mayor Michael Venezia. “By taking an underutilized parcel of land and turning it into beautiful park and waterfront space to be enjoyed by the public, we are fulfilling our commitment to preserving and enhancing open space. We would not have accomplished this without the efforts of Councilman Nick Joanow, who has advocated for this park for many years, Township Administrator Matthew Watkins, our excellent contractors and environmental experts, and I would like to thank them all. I also want to thank the Department of Environmental Protection and Freshwater Wetlands Mitigation Council for their important grant assistance to help us jump start this complex which will enrich the lives of Bloomfield residents for decades to come.”

NY/NJ Baykeeper has been vital in bringing the project to fruition, having served as an advocate for the project for the last 17 years.

“Lion’s Gate natural restoration is a legitimate all-in-one project that uses green infrastructure and smart planning to address the nested set of urban land use challenges, including: stormwater management, flooding, brownfield cleanup, natural habitat restoration, and the need for both more active playing fields and more passive greenfields,” said Greg Remaud, Baykeeper and CEO, NY/NJ Baykeeper.

Together, Bloomfield Township, Strauss and Associates, ARH, and Princeton Hydro secured $1.76 million in funding for this project from the New Jersey Freshwater Wetlands Mitigation Council and another several million dollars from NJDEP’s Office of Natural Resource Restoration.

To read more about our wetland restoration work, go here: http://bit.ly/PHwetland

 

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

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.

September Events Spotlight: Webinars, Conferences & Film Festival

Princeton Hydro is proud to participate in a number of conferences, events, and webinars throughout September:

 

September 6 at 12 pm: “Social Media Hacks” Webinar for the Society for American Military Engineers (SAME) Young Member Council 

SAME Young Member Council is hosting a webinar that will offer solutions for boosting social media presence and increasing engagement. Designed for social media beginners and experts alike, the webinar titled, “Social Media Hacks,” will be presented by Dana Patterson, Communications Strategist for Princeton Hydro. Participants will learn about creating successful social media strategy, utilizing free social media management tools, tracking social media analytics, and executing high-quality posts on various social media platforms. The webinar is free for SAME Members and $25 for all non-members.

Learn more and register.

 

September 9: Wild & Scenic Film Festival On Tour

Hosted by Musconetcong Watershed Association, the “Wild & Scenic Film Festival On Tour” celebrates the 50th Anniversary of the Wild and Scenic Rivers Act by bringing communities together to screen films that call attention to local and global environmental issues. The Hackettstown, NJ tour event, which Princeton Hydro is a proud sponsor of, will feature 11 short films including River Connections, a film that explores the importance of free-flowing rivers and highlights the recent Hughesville Dam removal project. An interactive panel event will follow the film screening and feature experts including MWA Executive Director Alan Hunt, Ph.D. and Princeton Hydro President Geoffrey Goll, P.E., who were both interviewed in the film. This event is free and open to the public, but registration is required.

Learn more and register.

 

September 12: Schuylkill Action Network’s (SAN) Water Utility Forum

This year’s SAN Forum will cover a variety of water-quality related topics, including perfluorinated compound (PFCs) and upcoming drinking water regulations. The forum will provide a platform to collaborate and share information, expertise, and technology to help achieve a shared vision of clean water and a healthy environment for the Schuylkill River and its tributaries. A variety of presentations will be offered during the forum, including one by Dr. Fred Lubnow, Director of Aquatics Programs for Princeton Hydro, on the topic of Harmful Algal Blooms (HABs).

Learn more and register.

 

September 15: Mercer County Park Commission’s River Days

Join Mercer County Park Commission for “River Days,” a free, family-friendly event at the Tulpehaking Nature Center with trail activities, arts and crafts, a raffle, and a neighborhood cookout on the back lawn of the nature center. Check out the Princeton Hydro air boat and chat with our Aquatics Field Director about the upcoming multi-year restoration of freshwater tidal wetlands in John A. Roebling Memorial Park. The restoration project is a partnership between Mercer County, New Jersey, Mercer County Park Commission, and Princeton Hydro.

Learn more.

 

September 23-26: 91st Annual Water Works Operators’ Association of Pennsylvania (WWOAP) Conference

WWOAP is hosting its 91st annual conference, which offers a diverse collection of professional presentations, workshops, networking events and an exhibit hall. Princeton Hydro’s Director of Aquatics Programs  Dr. Fred Lubnow is presenting on “Managing HABs and Their Associated Cyanotoxins in Raw Water.” Other presentation topics include “What Might Climate Change Look Like in Pennsylvania,” “A Multi-Lateral Approach to Water Loss Reduction,” and “Achieving Water Quality Optimization.”

View the full conference program.

 

September 25: New England Interstate Water Pollution Control Commission (NEIWPCC) Research Webinar

NEIWPCC is offering a free research webinar on modeling and flood-mitigation recommendations for a forested and urban Hudson River tributary watershed. The webinar takes a look at the Moodna Creek Watershed and Flood Mitigation Assessment and describes how flood models were used to inform recommendations for reducing and mitigating existing and anticipated flood risk. The assessment was conducted by environmental consultants at Princeton Hydro and GreenVest, and funded by NEIWPCC through the New York Department of Environmental Conservation’s Hudson River Estuary Program. This free webinar will be presented by Christiana Pollack, GISP, CFM, Environmental Scientist & GIS Manager for Princeton Hydro, and Jessica Jahre, CFM, AICP.

Learn more and register.

 

September 28: Alliance for NJ Environmental Education (ANJEE) Autumn Conference

Duke Farms will host ANJEE’s Autumn Conference, titled “Imagine a World Outdoors.” The conference, which takes place completely outdoors and does not include a single PowerPoint presentation, invites environmental education professionals throughout New Jersey to come together to collaborate around innovative ideas, learn and disseminate best practices, and network. Participants will explore natural history with local experts in birding, animal tracking, and plant identifying and learn trade secrets from experienced outdoor teachers who will share their methods and techniques. Princeton Hydro’s Dana Patterson and Pinelands Adventures’ Danielle Odom are teaching a workshop on “How to Bring Out the Inner Bird Nerd in your Students. ANJEE hopes the event will inspire participants to become more informed and dedicated stewards of the land.

Learn more and register.

 

Stay tuned for more event updates!

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.