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Array ( [0] => WP_Post Object ( [ID] => 3453 [post_author] => 3 [post_date] => 2019-04-22 18:02:55 [post_date_gmt] => 2019-04-22 18:02:55 [post_content] => Struggling fish species returns to spawning grounds for the first time in over a century, just months after dam removal completed For the first time in over a century, American Shad (Alosa sapidissima) have been discovered upstream from the former Columbia Dam site on the 42-mile long Paulins Kill river, an important tributary to the Delaware River in northwestern New Jersey. Princeton Hydro’s Senior Water Resources Engineer and avid fisherman, Dr. Clay Emerson, PE, CFM, caught an American Shad in the Paulins Kill miles above the previous dam site this past weekend. A successful collaboration between The Nature Conservancy, American Rivers, Princeton Hydro, U.S. Fish and Wildlife Service, and NJDEP Division of Fish and Wildlife Service, resulted in the removal of the out-of-commission hydroelectric Columbia Dam just months ago. Prior to this removal, American Shad and other migratory fish could not make it past the large dam structure to swim upstream to their important breeding grounds. “I was thrilled to feel the familiar hit and see the flash of an American Shad as I reeled the fish to shore. Being an avid shad fisherman and enthusiast, I knew the significance of seeing this beautiful fish back in a place where it's always belonged,” said Clay. “We are thrilled to witness the American Shad return upstream so quickly after the century-old Columbia dam was removed. It’s a testament to the nearly instant benefits that dam removal has on the riverine ecosystem.” The American shad’s return is an excellent sign of the overall ecological health and diversity of the river. Historically, dams, overfishing, and pollution have caused population decline in many of the major eastern U.S. rivers. American Shad, deemed the “Mid-Atlantic salmon,” are anadromous, which means they spend much of their lives in the ocean but return to rivers and their tributaries to spawn. This long distance swimmer makes it one of the Earth's great travelers. After spawning upstream in rivers of the East Coast, American Shad migrate to their primary habitat in the Atlantic Ocean up in the Gulf of Maine. Unlike the salmon of the Pacific Ocean, American Shad may return to their spawning grounds multiple times over their lifetime. The species is a key prey species for many large fish and cetaceans like dolphins and whales in the Atlantic Ocean. “The best indicator of river water quality improving in the Paulins Kill is the appearance of shad miles upstream from the Columbia Dam,” said Dr. Barbara Brummer, New Jersey State Director of The Nature Conservancy. “Today, we celebrate proof that with the 100-year dam impediment removed, they are once again successfully swimming up the river. I could not be happier! This is what teamwork and passion for nature can achieve. It is a great day for conservation in New Jersey, with many more great days for shad in the Paulins Kill to come.” Princeton Hydro was contracted to investigate, design, and apply for permits for the removal of this dam as requested by American Rivers in partnership with the New Jersey chapter of The Nature Conservancy. The firm investigated, designed, and prepared the necessary permits for the dam removal. The team of engineers and ecologists studied the feasibility of removal by collecting sediment samples, performing bioassay tests, and conducting a hydraulic analysis of upstream and downstream conditions. [caption id="attachment_2294" align="aligncenter" width="1566"] A view of the Columbia Dam at the beginning of the removal process.[/caption] “We are proud to be a part of this collaborative project, which has had an immediate and positive impact to the ecosystem of the Delaware River Watershed and its fishery resources,” said Princeton Hydro’s President Geoffrey Goll, PE. “Re-discovering this Delaware River diadromous icon upstream of the former dam is a very promising sign that the river will once again return to a major migration route and nursery for American Shad. This is why we do what we do!” This Columbia Dam Removal project could not have been possible without the hard work and dedication of the following partner organizations: The Nature Conservancy of New Jersey, American Rivers, Princeton Hydro, U.S. Fish and Wildlife Service, RiverLogic Solutions, NJDEP Division of Fish and Wildlife Service, and SumCo EcoContracting. Anglers are reminded, according to New Jersey fishing regulations, except for the Delaware River mainstem it is illegal to fish for shad in any fresh waters of New Jersey. Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of a dozens of small and large dams in the Northeast. To learn more about our fish passage and dam removal engineering services, visit: bit.ly/DamBarrier. … [post_title] => American Shad Discovered Just Miles Upstream of Former Columbia Dam [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => american-shad-return [to_ping] => [pinged] => [post_modified] => 2021-05-10 15:48:09 [post_modified_gmt] => 2021-05-10 15:48:09 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=3453 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [1] => WP_Post Object ( [ID] => 4727 [post_author] => 3 [post_date] => 2020-05-29 17:21:35 [post_date_gmt] => 2020-05-29 17:21:35 [post_content] => Hydrology is the study of the properties, distribution, and effects of water on the Earth’s surface, in the soil and underlying rocks, and in the atmosphere. The hydrologic cycle includes all of the ways in which water cycles from land to the atmosphere and back. Hydrologists study natural water-related events such as drought, rainfall, stormwater runoff, and floods, as well as how to predict and manage such events. On the application side, hydrology provides basic laws, equations, algorithms, procedures, and modeling of these events. Hydraulics is the study of the mechanical behavior of water in physical systems. In engineering terms, hydraulics is the analysis of how surface and subsurface waters move from one point to the next, such as calculating the depth of flow in a pipe or open channel. Hydraulic analysis is used to evaluate flow in rivers, streams, stormwater management networks, sewers, and much more. Combined hydrologic and hydraulic data, tools, and models are used for analyzing the impacts that waterflow - precipitation, stormwater, floods, and severe storms - will have on the existing infrastructure. This information is also used to make future land-use decisions and improvements that will work within the constraints of the hydrologic cycle and won’t exacerbate flooding or cause water quality impairment. Simply put, hydrologic and hydraulic modeling is an essential component of any effective flood risk management plan. Putting Hydrologic & Hydraulic Analysis to Work in Philadelphia Eastwick, a low-lying urbanized neighborhood in Southwest Philadelphia, is located in the Schuylkill River Watershed and is almost completely surrounded by water: The Cobbs and Darby creeks to the west, the Delaware River and wetlands to the south, and the Schuylkill River and Mingo Creek to the east. The community is at continual risk of both riverine and coastal flooding, and faces an uncertain future due to sea level rise and riverine flooding exacerbated by climate change. Princeton Hydro, along with project partners KeystoneConservation and University of Pennsylvania, conducted an analysis of Eastwick, the flood impacts created by the Lower Darby Creek, and the viability of several potential flood mitigation strategies. Flood mitigation approaches can be structural and nonstructural. Structural mitigation techniques focus on reconstructing landscapes, including building floodwalls/seawalls and installing floodgates/levees. Nonstructural measures work to reduce damage by removing people and property out of risk areas, including zoning, elevating structures, and conducting property buyouts. For Eastwick, studying stream dynamics is a key component to determining what type of flood mitigation strategies will yield the most success, as well as identifying the approaches that don’t work for this unique area. Princeton Hydro’s study focused on the key problem areas in Eastwick: the confluence of Darby Creek and Cobbs Creek; a constriction at Hook Road and 84th Street; and the Clearview Landfill, which is part of the Lower Darby Creek Superfund site. Additionally, the study sought to answer questions commonly asked by community members related to flooding conditions, with the main question being: What impact does the landfill have on area flooding? The built-up landfill is actually much higher than the stream bed, which creates a major disconnection between the floodplain and the stream channel. If the landfill didn’t exist, would the community still be at risk? If we increased the floodplain into the landfill, would that reduce neighborhood flooding? Princeton Hydro set out to answer these questions by developing riverine flooding models primarily using data from US Army Corps of Engineers (USACE), Federal Emergency Management Agency (FEMA), The National Oceanic and Atmospheric Administration (NOAA), and NOAA's National Weather Service (NWS). FEMA looks at the impacts of 1% storms that are primarily caused by precipitation events as well as coastal storms and storm surge. NOAA looks at the impacts of hurricanes. And, NOAA's NWS estimates sea, lake and overland storm surge heights from hurricanes. The models used 2D animation to show how the water flows in various scenarios, putting long-held assumptions to the test. The models looked at several different strategies, including the complete removal of the Clearview Landfill, which many people anticipated would be the silver bullet to the area’s flooding. The modeling revealed, however, that those long-held assumptions were invalid. Although the landfill removal completely alters the flood dynamics, the neighborhood would still flood even if the landfill weren’t there. Additionally, the modeling showed that the landfill is actually acting as a levee for a large portion of the Eastwick community. Ultimately, the research and modeling helped conclude that for the specific scenarios we studied, altering stream dynamics – a non-structural measure – is not a viable flood mitigation strategy. The USACE is currently undergoing a study in collaboration with the Philadelphia Water Department to test the feasibility of a levee system (a structural control measure), which would protect the Eastwick community by diverting the flood water. Funding for the study is expected to be approved in the coming year. Take a Deeper Look at Eastwick Flood Mitigation Efforts There are many studies highlighting flood mitigation strategies, environmental justice, and climate change vulnerability in Eastwick. Princeton Hydro Senior Project Manager and Senior Ecologist, Christiana Pollack CFM, GISP, presented on the flooding in Eastwick at the Consortium for Climate Risk in the Urban Northeast Seminar held at Drexel University. The seminar also featured presentations from Michael Nairn of the University of Pennsylvania Urban Studies Department, Ashley DiCaro of Interface Studios, and Dr. Philip Orton of Stevens Institute of Technology. You can watch the full seminar here: For more information about Princeton Hydro’s flood management services, go here: http://bit.ly/PHfloodplain. … [post_title] => Analyzing Mitigation Strategies for Flood-Prone Philadelphia Community [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => floodplain-management [to_ping] => [pinged] => [post_modified] => 2021-04-22 13:40:40 [post_modified_gmt] => 2021-04-22 13:40:40 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=4727 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 1 [filter] => raw ) [2] => WP_Post Object ( [ID] => 5534 [post_author] => 3 [post_date] => 2020-11-10 14:35:03 [post_date_gmt] => 2020-11-10 14:35:03 [post_content] => For over 100 years, the Old Mill Pond Dam in Spring Lake Heights, New Jersey has blocked critical anadromous fish species from reaching optimal spawning habitat. Today, we are thrilled to announce that, thanks to a fish ladder installed by the American Littoral Society (ALS), migratory fish can now scale the dam and access upstream spawning grounds. The 60-foot-long fish ladder is a device that allows a channel of water to flow through it and is engineered to create both the proper water depth and velocity for fish to navigate through. In this case, it will enable fish to scale the 10-foot-high dam and go deeper into Wreck Pond Brook. This video from ALS provides an up-close look at the Alaska-Steeppass Fish Ladder and more details about the project: [embed]https://youtu.be/b6FyQTu23lM[/embed] Re-opening river passage for migratory species improves not only the health of Wreck Pond Brook and its watershed, but it also benefits the overall ecosystem of the Atlantic shoreline and its coastal rivers. It also supports important recreational and commercial species, such as cod, haddock, and striped bass, which leads to a healthier economy. For over a century, the dam blocked anadromous fish like Alewife and Blueback river herring, from entering the Wreck Pond Brook Watershed. These fish spend most of their lives in the ocean but need freshwater in order to spawn. The Old Mill Pond Dam, an impassable obstruction for these migrating fish, was identified as a key contributor to the decline of Atlantic coast river herring populations. Subsequently, river herring were classified as National Oceanic and Atmospheric Administration (NOAA) Species of Special Concern and identified as requiring Concentrated Conservation Actions. The fish ladder, which was funded through the US Fish and Wildlife Service and implemented by ALS along with a variety of project partners, including Princeton Hydro, is one more major step in the ongoing effort to restore critical migratory fish spawning grounds, support a vibrant food web to the area, and rehabilitate Wreck Pond and its watershed. According to the ALS, “Now, instead of Old Mill Dam acting as the furthest migration destination for Alewife and Blueback river herring, these fish have the ability to navigate up the dam through the fish ladder and utilize roughly an additional mile of optimal spawning habitat. The ALS will add the Old Mill Dam fish ladder and newly accessible spawning habitat into its ongoing river herring monitoring surveys.” American Littoral Society promotes the study and conservation of marine life and habitat, protects the coast from harm, and empowers others to do the same. Learn more and get involved: littoralsociety.org. Princeton Hydro has designed, permitted, and overseen solutions for fish passage including the installation of technical and nature-like fishways and the removal of dozens of small and large dams throughout the Northeast. To learn more about our fish passage and dam removal engineering services, visit: bit.ly/DamBarrier. Images provided by the American Littoral Society. … [post_title] => After 100 Years, Fish Passage is Restored at Critical Migratory Fish Spawning Grounds in NJ [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => fish-ladder-old-mill-pond-dam [to_ping] => [pinged] => [post_modified] => 2021-02-25 06:29:53 [post_modified_gmt] => 2021-02-25 06:29:53 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=5534 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [3] => WP_Post Object ( [ID] => 5088 [post_author] => 3 [post_date] => 2020-06-18 18:08:57 [post_date_gmt] => 2020-06-18 18:08:57 [post_content] => To prevent harmful algal blooms (HABs) in New Jersey’s largest lake, a clay-based nutrient inactivating technology called Phoslock, is being applied in Lake Hopatcong this week. This is the largest Phoslock treatment to occur in the Northeastern U.S. The Phoslock treatment, which is happening in the southern end of the lake called Landing Channel, is expected to take approximately one week depending on the weather conditions. Over the course of the 2019 summer season, Lake Hopatcong suffered from large-scale and persistent HABs causing local and county health agencies to close off all beaches and issue advisories over large sections of the lake. These unprecedented conditions had significant negative impacts on the ecological, recreational, and economic resources of the lake and region. In order to combat HABs in this upcoming 2020 summer season, the Lake Hopatcong Commission has partnered with the Lake Hopatcong Foundation, four municipalities (Jefferson, Hopatcong, Mt. Arlington, and Roxbury), two counties (Morris and Sussex), and their environmental consultant, Princeton Hydro, to develop both short- and long-term lake management strategies. “The negative effects of HABs in our lake last year were numerous, widespread, and in some cases devastating,” recalled Donna Macalle-Holly of Lake Hopatcong Foundation. “It is imperative for every stakeholder to pool our resources to keep it from happening again. Collaboration is the only way to protect public health, as well as the health of New Jersey’s largest lake.” In an effort to evaluate a variety of innovative in-lake and watershed-based measures to prevent, mitigate, and/or control harmful algal blooms in Lake Hopatcong, the Lake Hopatcong Commission was awarded a $500k grant as part of New Jersey Department of Environmental Protection’s (NJDEP) new $13.5M initiative to reduce and prevent future harmful algal blooms in New Jersey. In addition to the $500k grant, the aforementioned local government and nonprofit stakeholders provided $330k in matching funds to implement and evaluate a variety of ways to address HABs in Lake Hopatcong. “Our lake community cannot sustain another year like 2019,” said Lake Hopatcong Commission Chairman Ron Smith. “Since the news of our grant award in early March, we have been working with our partners to make sure the projects are implemented in time for the 2020 season.” This week, the water resource engineering and natural resource management firm, Princeton Hydro—a lake management consultant to Lake Hopatcong for over two decades—is implementing the first and largest innovative measure as part of the NJDEP HABs grant-funded project. This involves treating 50 acres of the southern end of the lake with Phoslock, a clay-based product that inactivates phosphorus in both the water column and the sediments, making this critical nutrient unavailable for algal growth. The Phoslock treatment, which requires proper permitting by NJDEP, is applied as a slurry and will be distributed from a boat. The slurry will temporarily make the water appear turbid, but should disperse approximately two to six hours after each treatment. “We are expecting the Phoslock treatment to limit the growth of algae and therefore reduce the occurrence of harmful algal blooms in the lake this summer, keeping it open for recreation and business,” said Dr. Fred Lubnow, Director of Aquatic Resources at Princeton Hydro and leading HABs expert. “If this technology is deemed successful and cost-effective in Lake Hopatcong, we could set the precedent for large-scale HABs prevention in other lakes throughout New Jersey, and even across the nation.” Developed by the Australian national science agency CSIRO, Phoslock is frequently used to strip the water column of dissolved phosphorus, as well as to inactivate phosphorus generated from deep, anoxic sediments. Recently, at a smaller scale, it has been shown to inactivate the mobilization of phosphorus from shallow sediments where there is a mobilization of phosphorus from both chemical and biological processes. Algae uses phosphate, the biologically available form of phosphorus, as a food source to grow. When there is an excessive amount of phosphorus in a lake, algal growth can be dense and can negatively affect water quality. This excessive plant growth, caused by eutrophication, can both cause a lack of oxygen available, leading to fish kills, as well as produce harmful algal blooms with cyanotoxins, which are harmful to humans and pets. [caption id="attachment_5095" align="aligncenter" width="550"] Photo credit: SePRO Corporation[/caption] After Phoslock is applied, it sinks through the water column, binding phosphate as it moves towards the sediment. Once settled at the bottom of the lake, it forms a very thin layer and continues to bind phosphate released from the sediment, thus controlling the release of phosphorus into the lake. One pound of phosphorus has the potential to generate up to 1,100 lbs of wet algae biomass. However, 1.1 tons of Phoslock is capable of removing 24 pounds of phosphorus -- that’s over 26,000 lbs of wet algae biomass not growing in the lake for every 1.1 ton of Phoslock applied. In turn, Phoslock’s ability to suspend biologically available phosphorus is therefore a major step towards improving a lake’s water quality. As part of the NJDEP HABs grant funding, the stakeholder group will be evaluating the relative effectiveness of this treatment strategy. Because of its shallow depth and separation from the main lake, the Landing Channel area was a good candidate for evaluation of this technology. Princeton Hydro will conduct pre- and post-treatment monitoring of the Phoslock treatment area in order to conduct an objective evaluation of the cost effectiveness of the treatment as a means of preventing the development and/or mitigation of HABs. If the study indicates that Phoslock is a cost-effective treatment, the Lake Hopatcong Commission may consider additional trials in other sections of the lake, if funding is available. To learn more about HABs, check out our recent blog: [embed]https://www.princetonhydro.com/harmful-algae-blooms/[/embed] … [post_title] => Mitigating Harmful Algal Blooms at Lake Hopatcong: Largest Application of Phoslock in Northeast [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => lake-hopatcong-phoslock-treatment [to_ping] => [pinged] => [post_modified] => 2021-05-11 18:07:35 [post_modified_gmt] => 2021-05-11 18:07:35 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=5088 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 4 [filter] => raw ) [4] => WP_Post Object ( [ID] => 5583 [post_author] => 3 [post_date] => 2020-11-23 17:13:03 [post_date_gmt] => 2020-11-23 17:13:03 [post_content] => The Iowa Court and South Green Living Shoreline Project in Little Egg Harbor and Tuckerton, NJ, was awarded “Best Green Project” by Engineering News-Record magazine. The project is recognized for its use of innovative techniques to install new features to restore damage from Hurricane Sandy and protect the area from future storms. In 2012, Superstorm Sandy devastated communities throughout New Jersey and the entire eastern seaboard. Storm resilience, flood mitigation, and shoreline restoration have since become top priorities for coastal communities and low-lying areas. The Township of Little Egg Harbor, in conjunction with local partners including the Borough of Tuckerton, was the recipient of a $2.13 million Hurricane Sandy Coastal Resiliency Competitive Grant through the National Fish and Wildlife Foundation for a Marsh Restoration and Replenishment project. The grant was secured by New Jersey Future. The purpose of the project was to restore and replenish local marsh, wetlands, and beaches suffering extensive erosion along the shoreline. T&M Associates, as the Municipal Engineer of Record for the project, oversaw all aspects of the design and implementation. T&M contracted Princeton Hydro to perform sediment sampling/testing and conduct hydrographic surveys, and Arthur Chew Consulting to assist with the feasibility study and design of the dredging project. The project, which was completed in September 2019, provides long-term protection from erosion and will restore the vegetated shoreline habitats through strategic placement of plants, stone, sand fill, and other structural and organic materials. The living shoreline will help in the areas of storm protection, flood mitigation, and combatting shoreline erosion. The project was a great success for the Little Egg Harbor and Tuckerton communities. [caption id="attachment_5584" align="aligncenter" width="899"] [/caption] Since the restoration of Iowa Court and South Green Street, this living shoreline model has received significant attention and praise, including in the American Council of Engineering Companies of New Jersey 2020 Engineering Excellence Awards; the New Jersey Society of Municipal Engineers 2019 Project of the Year Awards; and, now, this "Best Green Project" award from Engineering News-Record. “There is growing interest in this approach from municipalities up and down the Jersey Shore. Storm and flood damage is still a pressing threat to hundreds of towns and boroughs, and it is widely accepted that storms like Sandy will only become more frequent due to the effects of climate change,” said Jason Worth, P.E., Group Manager at T&M Associates. “Thankfully, there is hope in innovation and creativity – with new approaches to living shorelines we can breathe life back into devastated beachfront communities and the natural ecosystems that support them.” Princeton Hydro specializes in the planning, design, permitting, implementing, and maintenance of coastal rehabilitation projects. To learn more about some of our ecosystem restoration and enhancement services, visit: bit.ly/PHcoastal. [caption id="attachment_5585" align="aligncenter" width="1016"] [/caption] … [post_title] => Living Shoreline in Ocean County, NJ Voted "Best Green Project" [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => living-shoreline-ocean-county-new-jersey [to_ping] => [pinged] => [post_modified] => 2021-04-22 18:56:57 [post_modified_gmt] => 2021-04-22 18:56:57 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=5583 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [5] => WP_Post Object ( [ID] => 4646 [post_author] => 3 [post_date] => 2020-03-17 21:17:55 [post_date_gmt] => 2020-03-17 21:17:55 [post_content] => The City of Elizabeth, the fourth most populous in New Jersey, is not exactly the first place that comes to mind when envisioning a wild landscape. This bustling urban area is well known for its Port Newark-Elizabeth Marine Terminal and the Philips 66 Bayway Refinery, and sits at the intersection of several major roadways like the NJ Turnpike and the Goethals Bridge. The landscape, which was once teeming with dense wetlands and associated habitats, is now heavily urbanized with a vast mix of residential, commercial, and industrial properties. The largely channelized Elizabeth River courses through the city for 4.2 miles before draining into the Arthur Kill waterway. However, in this 14-square mile city, native flora and fauna are taking root again thanks to ecological restoration and mitigation efforts. Urban landscapes like Elizabeth can pose significant challenges for restoration efforts, but they also provide an array of opportunity for significant ecological uplift. In 2004, Princeton Hydro was retained to restore an 18-acre site adjacent to the Elizabeth Seaport Business Park, which is located in an area that was once part of a large contiguous wetland system abutting Newark Bay. The site was comprised of a significantly disturbed mosaic of wetland and upland areas and a monoculture of Phragmites australis, also known as Common Reed, on historic fill. Historic fill consists of non-native material, historically placed to raise grades, and typically contains contaminated material not associated with the operations of the site on which it was placed. The highly invasive Phragmites australis had overtaken most of the wetland areas, and the upland woodland areas only contained four tree species, mostly Eastern Cottonwood, with very low wildlife value. The 18-acre site had huge potential but was significantly degraded and was being vastly underutilized. Overall, the mitigation plan focused on the enhancement of existing wetland and transition areas to increase the area’s wildlife value through the establishment of a more desirable, diverse assemblage of native species subsequent to eradication of non-native-invasive species.
For the first time in over a century, American Shad (Alosa sapidissima) have been discovered upstream from the former Columbia Dam site on the 42-mile long Paulins Kill river, an important tributary to the Delaware River in northwestern New Jersey. Princeton Hydro’s Senior Water Resources Engineer and avid fisherman, Dr. Clay Emerson, PE, CFM, caught an American Shad in the Paulins Kill miles above the previous dam site this past weekend.
A successful collaboration between The Nature Conservancy, American Rivers, Princeton Hydro, U.S. Fish and Wildlife Service, and NJDEP Division of Fish and Wildlife Service, resulted in the removal of the out-of-commission hydroelectric Columbia Dam just months ago. Prior to this removal, American Shad and other migratory fish could not make it past the large dam structure to swim upstream to their important breeding grounds.
“I was thrilled to feel the familiar hit and see the flash of an American Shad as I reeled the fish to shore. Being an avid shad fisherman and enthusiast, I knew the significance of seeing this beautiful fish back in a place where it's always belonged,” said Clay. “We are thrilled to witness the American Shad return upstream so quickly after the century-old Columbia dam was removed. It’s a testament to the nearly instant benefits that dam removal has on the riverine ecosystem.”
The American shad’s return is an excellent sign of the overall ecological health and diversity of the river. Historically, dams, overfishing, and pollution have caused population decline in many of the major eastern U.S. rivers. American Shad, deemed the “Mid-Atlantic salmon,” are anadromous, which means they spend much of their lives in the ocean but return to rivers and their tributaries to spawn. This long distance swimmer makes it one of the Earth's great travelers. After spawning upstream in rivers of the East Coast, American Shad migrate to their primary habitat in the Atlantic Ocean up in the Gulf of Maine. Unlike the salmon of the Pacific Ocean, American Shad may return to their spawning grounds multiple times over their lifetime. The species is a key prey species for many large fish and cetaceans like dolphins and whales in the Atlantic Ocean.
“The best indicator of river water quality improving in the Paulins Kill is the appearance of shad miles upstream from the Columbia Dam,” said Dr. Barbara Brummer, New Jersey State Director of The Nature Conservancy. “Today, we celebrate proof that with the 100-year dam impediment removed, they are once again successfully swimming up the river. I could not be happier! This is what teamwork and passion for nature can achieve. It is a great day for conservation in New Jersey, with many more great days for shad in the Paulins Kill to come.”
Princeton Hydro was contracted to investigate, design, and apply for permits for the removal of this dam as requested by American Rivers in partnership with the New Jersey chapter of The Nature Conservancy. The firm investigated, designed, and prepared the necessary permits for the dam removal. The team of engineers and ecologists studied the feasibility of removal by collecting sediment samples, performing bioassay tests, and conducting a hydraulic analysis of upstream and downstream conditions.
“We are proud to be a part of this collaborative project, which has had an immediate and positive impact to the ecosystem of the Delaware River Watershed and its fishery resources,” said Princeton Hydro’s President Geoffrey Goll, PE. “Re-discovering this Delaware River diadromous icon upstream of the former dam is a very promising sign that the river will once again return to a major migration route and nursery for American Shad. This is why we do what we do!”
This Columbia Dam Removal project could not have been possible without the hard work and dedication of the following partner organizations: The Nature Conservancy of New Jersey, American Rivers, Princeton Hydro, U.S. Fish and Wildlife Service, RiverLogic Solutions, NJDEP Division of Fish and Wildlife Service, and SumCo EcoContracting.
Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of a dozens of small and large dams in the Northeast. To learn more about our fish passage and dam removal engineering services, visit: bit.ly/DamBarrier.
…
Hydrology is the study of the properties, distribution, and effects of water on the Earth’s surface, in the soil and underlying rocks, and in the atmosphere. The hydrologic cycle includes all of the ways in which water cycles from land to the atmosphere and back. Hydrologists study natural water-related events such as drought, rainfall, stormwater runoff, and floods, as well as how to predict and manage such events. On the application side, hydrology provides basic laws, equations, algorithms, procedures, and modeling of these events.
Hydraulics is the study of the mechanical behavior of water in physical systems. In engineering terms, hydraulics is the analysis of how surface and subsurface waters move from one point to the next, such as calculating the depth of flow in a pipe or open channel. Hydraulic analysis is used to evaluate flow in rivers, streams, stormwater management networks, sewers, and much more.
Combined hydrologic and hydraulic data, tools, and models are used for analyzing the impacts that waterflow - precipitation, stormwater, floods, and severe storms - will have on the existing infrastructure. This information is also used to make future land-use decisions and improvements that will work within the constraints of the hydrologic cycle and won’t exacerbate flooding or cause water quality impairment.
Simply put, hydrologic and hydraulic modeling is an essential component of any effective flood risk management plan.
Eastwick, a low-lying urbanized neighborhood in Southwest Philadelphia, is located in the Schuylkill River Watershed and is almost completely surrounded by water: The Cobbs and Darby creeks to the west, the Delaware River and wetlands to the south, and the Schuylkill River and Mingo Creek to the east. The community is at continual risk of both riverine and coastal flooding, and faces an uncertain future due to sea level rise and riverine flooding exacerbated by climate change.
Princeton Hydro, along with project partners KeystoneConservation and University of Pennsylvania, conducted an analysis of Eastwick, the flood impacts created by the Lower Darby Creek, and the viability of several potential flood mitigation strategies.
Flood mitigation approaches can be structural and nonstructural. Structural mitigation techniques focus on reconstructing landscapes, including building floodwalls/seawalls and installing floodgates/levees. Nonstructural measures work to reduce damage by removing people and property out of risk areas, including zoning, elevating structures, and conducting property buyouts.
For Eastwick, studying stream dynamics is a key component to determining what type of flood mitigation strategies will yield the most success, as well as identifying the approaches that don’t work for this unique area.
Princeton Hydro’s study focused on the key problem areas in Eastwick: the confluence of Darby Creek and Cobbs Creek; a constriction at Hook Road and 84th Street; and the Clearview Landfill, which is part of the Lower Darby Creek Superfund site. Additionally, the study sought to answer questions commonly asked by community members related to flooding conditions, with the main question being: What impact does the landfill have on area flooding?
The built-up landfill is actually much higher than the stream bed, which creates a major disconnection between the floodplain and the stream channel. If the landfill didn’t exist, would the community still be at risk? If we increased the floodplain into the landfill, would that reduce neighborhood flooding?
Princeton Hydro set out to answer these questions by developing riverine flooding models primarily using data from US Army Corps of Engineers (USACE), Federal Emergency Management Agency (FEMA), The National Oceanic and Atmospheric Administration (NOAA), and NOAA's National Weather Service (NWS). FEMA looks at the impacts of 1% storms that are primarily caused by precipitation events as well as coastal storms and storm surge. NOAA looks at the impacts of hurricanes. And, NOAA's NWS estimates sea, lake and overland storm surge heights from hurricanes.
The models used 2D animation to show how the water flows in various scenarios, putting long-held assumptions to the test.
The models looked at several different strategies, including the complete removal of the Clearview Landfill, which many people anticipated would be the silver bullet to the area’s flooding. The modeling revealed, however, that those long-held assumptions were invalid. Although the landfill removal completely alters the flood dynamics, the neighborhood would still flood even if the landfill weren’t there. Additionally, the modeling showed that the landfill is actually acting as a levee for a large portion of the Eastwick community.
Ultimately, the research and modeling helped conclude that for the specific scenarios we studied, altering stream dynamics – a non-structural measure – is not a viable flood mitigation strategy.
The USACE is currently undergoing a study in collaboration with the Philadelphia Water Department to test the feasibility of a levee system (a structural control measure), which would protect the Eastwick community by diverting the flood water. Funding for the study is expected to be approved in the coming year.
There are many studies highlighting flood mitigation strategies, environmental justice, and climate change vulnerability in Eastwick. Princeton Hydro Senior Project Manager and Senior Ecologist, Christiana Pollack CFM, GISP, presented on the flooding in Eastwick at the Consortium for Climate Risk in the Urban Northeast Seminar held at Drexel University. The seminar also featured presentations from Michael Nairn of the University of Pennsylvania Urban Studies Department, Ashley DiCaro of Interface Studios, and Dr. Philip Orton of Stevens Institute of Technology.
For more information about Princeton Hydro’s flood management services, go here: http://bit.ly/PHfloodplain.
For over 100 years, the Old Mill Pond Dam in Spring Lake Heights, New Jersey has blocked critical anadromous fish species from reaching optimal spawning habitat. Today, we are thrilled to announce that, thanks to a fish ladder installed by the American Littoral Society (ALS), migratory fish can now scale the dam and access upstream spawning grounds.
The 60-foot-long fish ladder is a device that allows a channel of water to flow through it and is engineered to create both the proper water depth and velocity for fish to navigate through. In this case, it will enable fish to scale the 10-foot-high dam and go deeper into Wreck Pond Brook.
This video from ALS provides an up-close look at the Alaska-Steeppass Fish Ladder and more details about the project:
Re-opening river passage for migratory species improves not only the health of Wreck Pond Brook and its watershed, but it also benefits the overall ecosystem of the Atlantic shoreline and its coastal rivers. It also supports important recreational and commercial species, such as cod, haddock, and striped bass, which leads to a healthier economy.
For over a century, the dam blocked anadromous fish like Alewife and Blueback river herring, from entering the Wreck Pond Brook Watershed. These fish spend most of their lives in the ocean but need freshwater in order to spawn. The Old Mill Pond Dam, an impassable obstruction for these migrating fish, was identified as a key contributor to the decline of Atlantic coast river herring populations. Subsequently, river herring were classified as National Oceanic and Atmospheric Administration (NOAA) Species of Special Concern and identified as requiring Concentrated Conservation Actions.
The fish ladder, which was funded through the US Fish and Wildlife Service and implemented by ALS along with a variety of project partners, including Princeton Hydro, is one more major step in the ongoing effort to restore critical migratory fish spawning grounds, support a vibrant food web to the area, and rehabilitate Wreck Pond and its watershed.
According to the ALS, “Now, instead of Old Mill Dam acting as the furthest migration destination for Alewife and Blueback river herring, these fish have the ability to navigate up the dam through the fish ladder and utilize roughly an additional mile of optimal spawning habitat. The ALS will add the Old Mill Dam fish ladder and newly accessible spawning habitat into its ongoing river herring monitoring surveys.”
American Littoral Society promotes the study and conservation of marine life and habitat, protects the coast from harm, and empowers others to do the same. Learn more and get involved: littoralsociety.org.
Princeton Hydro has designed, permitted, and overseen solutions for fish passage including the installation of technical and nature-like fishways and the removal of dozens of small and large dams throughout the Northeast. To learn more about our fish passage and dam removal engineering services, visit: bit.ly/DamBarrier.
Images provided by the American Littoral Society.
To prevent harmful algal blooms (HABs) in New Jersey’s largest lake, a clay-based nutrient inactivating technology called Phoslock, is being applied in Lake Hopatcong this week. This is the largest Phoslock treatment to occur in the Northeastern U.S. The Phoslock treatment, which is happening in the southern end of the lake called Landing Channel, is expected to take approximately one week depending on the weather conditions.
Over the course of the 2019 summer season, Lake Hopatcong suffered from large-scale and persistent HABs causing local and county health agencies to close off all beaches and issue advisories over large sections of the lake. These unprecedented conditions had significant negative impacts on the ecological, recreational, and economic resources of the lake and region. In order to combat HABs in this upcoming 2020 summer season, the Lake Hopatcong Commission has partnered with the Lake Hopatcong Foundation, four municipalities (Jefferson, Hopatcong, Mt. Arlington, and Roxbury), two counties (Morris and Sussex), and their environmental consultant, Princeton Hydro, to develop both short- and long-term lake management strategies.
“The negative effects of HABs in our lake last year were numerous, widespread, and in some cases devastating,” recalled Donna Macalle-Holly of Lake Hopatcong Foundation. “It is imperative for every stakeholder to pool our resources to keep it from happening again. Collaboration is the only way to protect public health, as well as the health of New Jersey’s largest lake.”
In an effort to evaluate a variety of innovative in-lake and watershed-based measures to prevent, mitigate, and/or control harmful algal blooms in Lake Hopatcong, the Lake Hopatcong Commission was awarded a $500k grant as part of New Jersey Department of Environmental Protection’s (NJDEP) new $13.5M initiative to reduce and prevent future harmful algal blooms in New Jersey. In addition to the $500k grant, the aforementioned local government and nonprofit stakeholders provided $330k in matching funds to implement and evaluate a variety of ways to address HABs in Lake Hopatcong.
“Our lake community cannot sustain another year like 2019,” said Lake Hopatcong Commission Chairman Ron Smith. “Since the news of our grant award in early March, we have been working with our partners to make sure the projects are implemented in time for the 2020 season.”
This week, the water resource engineering and natural resource management firm, Princeton Hydro—a lake management consultant to Lake Hopatcong for over two decades—is implementing the first and largest innovative measure as part of the NJDEP HABs grant-funded project. This involves treating 50 acres of the southern end of the lake with Phoslock, a clay-based product that inactivates phosphorus in both the water column and the sediments, making this critical nutrient unavailable for algal growth. The Phoslock treatment, which requires proper permitting by NJDEP, is applied as a slurry and will be distributed from a boat. The slurry will temporarily make the water appear turbid, but should disperse approximately two to six hours after each treatment.
“We are expecting the Phoslock treatment to limit the growth of algae and therefore reduce the occurrence of harmful algal blooms in the lake this summer, keeping it open for recreation and business,” said Dr. Fred Lubnow, Director of Aquatic Resources at Princeton Hydro and leading HABs expert. “If this technology is deemed successful and cost-effective in Lake Hopatcong, we could set the precedent for large-scale HABs prevention in other lakes throughout New Jersey, and even across the nation.”
Developed by the Australian national science agency CSIRO, Phoslock is frequently used to strip the water column of dissolved phosphorus, as well as to inactivate phosphorus generated from deep, anoxic sediments. Recently, at a smaller scale, it has been shown to inactivate the mobilization of phosphorus from shallow sediments where there is a mobilization of phosphorus from both chemical and biological processes.
Algae uses phosphate, the biologically available form of phosphorus, as a food source to grow. When there is an excessive amount of phosphorus in a lake, algal growth can be dense and can negatively affect water quality. This excessive plant growth, caused by eutrophication, can both cause a lack of oxygen available, leading to fish kills, as well as produce harmful algal blooms with cyanotoxins, which are harmful to humans and pets.
After Phoslock is applied, it sinks through the water column, binding phosphate as it moves towards the sediment. Once settled at the bottom of the lake, it forms a very thin layer and continues to bind phosphate released from the sediment, thus controlling the release of phosphorus into the lake. One pound of phosphorus has the potential to generate up to 1,100 lbs of wet algae biomass. However, 1.1 tons of Phoslock is capable of removing 24 pounds of phosphorus -- that’s over 26,000 lbs of wet algae biomass not growing in the lake for every 1.1 ton of Phoslock applied. In turn, Phoslock’s ability to suspend biologically available phosphorus is therefore a major step towards improving a lake’s water quality.
As part of the NJDEP HABs grant funding, the stakeholder group will be evaluating the relative effectiveness of this treatment strategy. Because of its shallow depth and separation from the main lake, the Landing Channel area was a good candidate for evaluation of this technology. Princeton Hydro will conduct pre- and post-treatment monitoring of the Phoslock treatment area in order to conduct an objective evaluation of the cost effectiveness of the treatment as a means of preventing the development and/or mitigation of HABs. If the study indicates that Phoslock is a cost-effective treatment, the Lake Hopatcong Commission may consider additional trials in other sections of the lake, if funding is available.
The Iowa Court and South Green Living Shoreline Project in Little Egg Harbor and Tuckerton, NJ, was awarded “Best Green Project” by Engineering News-Record magazine. The project is recognized for its use of innovative techniques to install new features to restore damage from Hurricane Sandy and protect the area from future storms.
In 2012, Superstorm Sandy devastated communities throughout New Jersey and the entire eastern seaboard. Storm resilience, flood mitigation, and shoreline restoration have since become top priorities for coastal communities and low-lying areas.
The Township of Little Egg Harbor, in conjunction with local partners including the Borough of Tuckerton, was the recipient of a $2.13 million Hurricane Sandy Coastal Resiliency Competitive Grant through the National Fish and Wildlife Foundation for a Marsh Restoration and Replenishment project. The grant was secured by New Jersey Future. The purpose of the project was to restore and replenish local marsh, wetlands, and beaches suffering extensive erosion along the shoreline.
T&M Associates, as the Municipal Engineer of Record for the project, oversaw all aspects of the design and implementation. T&M contracted Princeton Hydro to perform sediment sampling/testing and conduct hydrographic surveys, and Arthur Chew Consulting to assist with the feasibility study and design of the dredging project.
The project, which was completed in September 2019, provides long-term protection from erosion and will restore the vegetated shoreline habitats through strategic placement of plants, stone, sand fill, and other structural and organic materials. The living shoreline will help in the areas of storm protection, flood mitigation, and combatting shoreline erosion. The project was a great success for the Little Egg Harbor and Tuckerton communities.
Since the restoration of Iowa Court and South Green Street, this living shoreline model has received significant attention and praise, including in the American Council of Engineering Companies of New Jersey 2020 Engineering Excellence Awards; the New Jersey Society of Municipal Engineers 2019 Project of the Year Awards; and, now, this "Best Green Project" award from Engineering News-Record.
“There is growing interest in this approach from municipalities up and down the Jersey Shore. Storm and flood damage is still a pressing threat to hundreds of towns and boroughs, and it is widely accepted that storms like Sandy will only become more frequent due to the effects of climate change,” said Jason Worth, P.E., Group Manager at T&M Associates. “Thankfully, there is hope in innovation and creativity – with new approaches to living shorelines we can breathe life back into devastated beachfront communities and the natural ecosystems that support them.”
Princeton Hydro specializes in the planning, design, permitting, implementing, and maintenance of coastal rehabilitation projects. To learn more about some of our ecosystem restoration and enhancement services, visit: bit.ly/PHcoastal.
The City of Elizabeth, the fourth most populous in New Jersey, is not exactly the first place that comes to mind when envisioning a wild landscape. This bustling urban area is well known for its Port Newark-Elizabeth Marine Terminal and the Philips 66 Bayway Refinery, and sits at the intersection of several major roadways like the NJ Turnpike and the Goethals Bridge. The landscape, which was once teeming with dense wetlands and associated habitats, is now heavily urbanized with a vast mix of residential, commercial, and industrial properties. The largely channelized Elizabeth River courses through the city for 4.2 miles before draining into the Arthur Kill waterway. However, in this 14-square mile city, native flora and fauna are taking root again thanks to ecological restoration and mitigation efforts.
Urban landscapes like Elizabeth can pose significant challenges for restoration efforts, but they also provide an array of opportunity for significant ecological uplift.
In 2004, Princeton Hydro was retained to restore an 18-acre site adjacent to the Elizabeth Seaport Business Park, which is located in an area that was once part of a large contiguous wetland system abutting Newark Bay. The site was comprised of a significantly disturbed mosaic of wetland and upland areas and a monoculture of Phragmites australis, also known as Common Reed, on historic fill. Historic fill consists of non-native material, historically placed to raise grades, and typically contains contaminated material not associated with the operations of the site on which it was placed.
The highly invasive Phragmites australis had overtaken most of the wetland areas, and the upland woodland areas only contained four tree species, mostly Eastern Cottonwood, with very low wildlife value. The 18-acre site had huge potential but was significantly degraded and was being vastly underutilized. Overall, the mitigation plan focused on the enhancement of existing wetland and transition areas to increase the area’s wildlife value through the establishment of a more desirable, diverse assemblage of native species subsequent to eradication of non-native-invasive species.
The freshwater wetland aspect of the mitigation plan, which included inundated emergent, emergent, and forested habitat, was designed to be a combination of wetland creation (2.40 acres) and enhancement (8.79 acres), emphasizing the establishment of more species rich wetlands in order to increase biodiversity and improve the site’s wildlife food value.
The upland forest aspect of the mitigation plan involved the enhancement of 5.40 acres and creation of 1.45 acres of upland forest to foster the development of a species rich and structurally complex upland forest. The upland areas targeted for enhancement/creation consisted of areas where woody vegetation was lacking or forested areas that were dominated by eastern cottonwood.
The project team worked to remove Phragmites australis from the site utilizing a combination of herbicide and mechanical removal techniques. Once the Phragmites australis was cleared, the team installed 27,000 two-inch native herbaceous plant plugs in the wetland portions of the mitigation site, and 2,705 native trees/shrubs throughout the site.
In order to ensure the continued success of the mitigation project, monitoring is regularly conducted at the site. A monitoring report conducted at the end of 2019 revealed a plethora of well-established habitat areas, a diverse community of plant and tree species, and a thriving, highly-functional landscape.
Presently, the Elizabeth Seaport Business Park Mitigation Site boasts a variety of productive wildlife habitats that are rare in a highly urbanized setting and provides valuable ecosystem services, including sediment retention and roosting, foraging, and nesting opportunities for both resident and migratory bird species with over 150 bird species identified within the mitigation site.
This project serves as an example of how degraded urban areas can be successfully rehabilitated and the land’s natural function restored and enhanced. If you'd like to learn more about this project from our Natural Resources Senior Project Manager Michael Rehman, check out the video of his presentation at the 2020 Delaware Wetlands Conference below.
If you're interested in learning more about our wetland restoration and mitigation services, go here!
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