Princeton Hydro Projects Recap

In Case You Missed It:
A Recap of Projects Recently Completed by the
Princeton Hydro Aquatic & Engineering Departments

Members of our New England Regional Office team conducted a detailed survey at a culvert prioritized for replacement in the Town of Stony Point, New York. This structure was one of several identified as important to both habitat and flood risk during the development of Stony Point’s Road-Stream Crossing Management Plan. The Princeton Hydro team will use the collected data to develop a conceptual design and implementation strategy for a replacement structure using the Stream Simulation design method developed by the U.S. Forest Service.

Special thanks to Paul Woodworth, Fluvial Geomorphologist, and Sophie Breitbart, Staff Scientist, for their excellent work on this project!

The Truxor was put to work dredging a pond in Union Gap, New Jersey. The Truxor is an extremely versatile amphibious machine that can perform a variety of functions, including weed cutting and harvesting, mat algae and debris removal, silt pumping, channel excavation, oil spill clean-up, and much more!

We recently designed and installed a solar-powered aeration system in Hillsborough, New Jersey. Solar pond and lake aeration systems are cost-effective, eco-friendly, sustainable, and they eliminate the need to run direct-wired electrical lines to remote locations. Princeton Hydro designs, installs and maintains various aeration and sub-surface destratification systems for public drinking water purveyors, municipal and county parks, private and public golf courses, and large lake communities throughout the East Coast.

Here’s a look at a project in Elizabeth, New Jersey to clear the area of phragmites. Phragmites is an invasive weed that forms dense thickets of vegetation unsuitable for native fauna. It also outcompetes native vegetation and lowers local plant diversity. Previously, the entire site was filled with phragmites. Late last year, we utilized the Marsh Master to remove the invasive weed. Now that its almost Spring, we’re back at the site using the Marsh Master to mill and cultivate the ground in preparation for re-planting native plant species. A big shout out to our Aquatic Specialist John Eberly for his great work on this project!

In this photo, our intern and engineering student currently studying at Stevens Institute of Technology, Veronica Moditz, is gathering data on the Hughesville Dam removal. She’s using GPS to check the elevation of the constructed riffle on the beautiful Musconetcong River.

Members of the Princeton Hydro team worked in South New Jersey doing annual maintenance on nine stormwater infiltration basins that were also designed and constructed by Princeton Hydro. The maintenance work involves clearing vegetation from the basins to ensure the organic matter does not impede infiltration of the water as per the basins’ design. This project also involves the management of invasive plant species within the basins. Stormwater infiltration basins provide numerous benefits including preventing flooding and downstream erosion, improving water quality in adjacent waterbodies, reducing the volume of stormwater runoff, and increasing ground water recharge.

We recently completed a project in New Jersey for which we used our Truxor machine to dredge a stormwater retention basin. The basin had accumulated large amounts of sediment which were impeding the flow of water into the basin. We equipped the Truxor with its standard bucket attachment and a hydraulic dredge pump. The dredging operation was a success and now the basin is clear and functioning properly.

Stay Tuned for More Updates!

The Plight of Aging Dams, and One Solution

As dams age, the danger to life and property around them increases. If they were to suddenly fail and flood downstream communities and infrastructure, there would be serious loss of property and life. More and more, dam removal has become the best option for property owners who no longer want or can no longer afford the rising cost of maintenance and repair work required to maintain such a complex structure.

The Courier-Post recently published this Commentary piece titled, “The Plight of Aging Dams, and One Solution”, which was written by Princeton Hydro’s Vice President and Principal Engineer Geoffrey M. Goll:

Many of our nation’s dams, while originally intended to provide benefits for mills, water supply and energy generation, are severely aged and unmaintained. Nearly 20,000 of the dams on the Army Corps of Engineers’ National Inventory of Dams – which doesn’t even include many dams that are not inventoried or known about – were built in the 1960s. With expected lifespans of 50 years, these dams have reached their limit. And by 2020, 70 percent of all dams will be over 50 years old. Like roads and bridges, dams also require upkeep, maintenance and eventually removal or rehabilitation.

As dams age, the danger to life and property around them increases. If they were to suddenly fail and flood downstream communities and infrastructure, there would be loss of property and life. The Association of State Dam Safety Officials, the professional organization for dam safety engineering professionals and regulators, estimates there would need to be a $21 billion investment to repair just 2,000 deficient, high-hazard dams. More and more, the removal of dams has become an option for owners who no longer want or no longer can afford the rising cost of maintenance and repair work required to maintain such a complex structure.

For dams like this, removal benefits local economies, and eliminates threats to people and property in local communities. There are also many byproduct benefits, including restoring fish migration routes, improving water quality, restoring floodplain functions and values, and increasing biodiversity.

On Sept. 8, we had the honor of meeting the Secretary of the Interior Sally Jewell during a visit of our Hughesville Dam removal project on the Musconetcong River, located in northwestern New Jersey. This project exemplifies the successes that can be achieved through public-private partnerships, including local communities, state and federal agencies, nongovernmental organizations, and private commercial entities. This is the fifth dam removed on the Musconetcong River by a coalition of stakeholders, led by the Musconetcong Watershed Association. The Department of the Interior (specifically, the U.S. Fish and Wildlife Service) provided funding to remove this very old, out-of-compliance dam.

The success of these partnerships is due to the unique strengths that each organization brings to the table. This project achieved the removal of a flood and safety hazard, and will restore additional river miles for migratory fish, improve water quality by removing the heat sink of the reservoir, and provide additional safe passage for recreation along the river.

It is easy to see why Secretary Jewell chose this site to visit, but the old and outdated dam at Hughesville is far from alone. Across the nation, we need to remove dams like this at a much larger scale – aging dams that no longer are of value to us, but increase the danger to those who live downstream. If we can build on this momentum and start to address the issue of dam safety compliance on a national scale, we can address these threats to American’s safety and strengthen local economies.

The Westtown Dam and Lake Restoration Project is Now Complete!

westtown-0720161456Princeton Hydro is proud to announce the completion of the Westtown dam restoration and dredging project. For the past 10 years, Princeton Hydro has been working with the Westtown School on dam safety compliance and lake restoration and is the engineer-of-record for the restoration of the Westtown dam and lake.

Westtown School, a hallmark of the Westtown Lake community, initially contracted Princeton Hydro to complete dam inspections and assess the lake in terms of its environmental health and the need for dredging. The completion of this project is a testament to the School’s commitment to its mission of “inspiring and preparing its graduates to be stewards and leaders of a better world”. The School leads by example through practicing dam safety compliance and working to restore the lake for future generations.

westtown-img_2438For the dam, Princeton Hydro completed periodic visual inspections, dam breach and inundation analysis, the preparation of an Emergency Action Plan (EAP), and the Operations and Maintenance Manual.

For rehabilitation, Princeton Hydro designed the dam to be able to pass the 100-year flood event via a completely new drop spillway and outfall barrel, and the construction of an auxiliary/emergency cast-in-place stepped spillway. As part of the rehabilitation of the dam, Princeton Hydro surveyed and designed the dredging of 56,000 cubic yards of sediment, the rehabilitation of the lake’s sedimentation forebay and spillway, and the enlargement of a culvert on Westtown Road, immediately downstream of the dam. The culvert replacement was required due to the closure of two secondary outlets on the dam and corresponding culverts below Westtown Road.

westtown-0713161041aThis project also required a variety of permits, including a Chester County soil erosion and sediment control plan approval, a Dam Safety construction permit, a PADEP General Permit 11 for the road crossing, and a US Army Corps of Engineers Individual Permit in compliance with the Federal Clean Water Act.

Additionally, Princeton Hydro successfully navigated interests for two species of concern: the bog turtle (federal and state listed) habitat and red-bellied turtle (state listed) populations.

Following design and permitting, Princeton Hydro provided construction documentation and administration, including the review of shop drawings, monitoring soil compaction, inspecting concrete pours and collecting concrete test cylinders for break tests (ACI certified engineers), completing monthly progress reports, reviewing payment requests and change orders, and attend bi-weekly project meetings with the client. Flyway Excavating, the contractor for the project, worked seamlessly with the School and Princeton Hydro to accomplish the overall goals of the design.

The Westtown project is an excellent example of Princeton Hydro’s turnkey engineering, permitting, and construction administration services. Please contact us if you have a similar project you need assistance with or have questions about.

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*Photos courtesy of Flyway Excavating.

 

 

 

Deal Lake Improves Water Quality on a Sustainable Basis

Success Spotlight: Deal Lake Watershed Protection Plan Implementation Project

Deal Lake Commission, Interlaken, New Jersey

Deal Lake is the largest of New Jersey’s coastal lakes, encompassing 155 acres and spanning over 27 miles of shoreline. The lake’s 4,400-acre watershed is highly developed, with the majority of development dating back to the 1940s-1960s. As a result, stormwater management, particularly with respect to water quality and volume management, is largely lacking.

Since 1980, the Deal Lake Commission (DLC) has served as the State-appointed steward of the lake.  Princeton Hydro secured the DLC $450,000 in 319(h) funding to implement the lake’s New Jersey Department of Environmental Protection-approved Watershed Protection Plan. The 319(h) funding was used by the DLC to conduct three projects designed to decrease stormwater-based pollutant loading, improve the lake’s water quality, and restore heavily eroded sections of the shoreline.

Asbury Park Comstock Street MTD

Screen Shot 2016-05-23 at 9.20.04 AMThis project involved the installation of a manufactured treatment device (MTD). MTDs are very effective “retrofit” solutions that can be used to address stormwater issues even in highly developed areas. The MTD installation was complicated by site constraints including sub-surface infrastructure. Post-installation field testing and STEPL modeling conducted by Princeton Hydro confirmed that the MTD significantly decreased the pollutant loading from one of the lake’s major stormwater outfalls.

 

Colonial Terrace Golf Course Bioretention BMPs
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Princeton Hydro conducted the field testing, engineering design, and permitting of three bio-infiltration basins constructed at the Colonial Terrace Golf Course (CTGC). Post-project-completion field testing showed each basin is capable of fully infiltrating the runoff generated by storms as great as 1.5 inches per hour. In addition, over 300 feet of eroded shoreline was stabilized with native plants. Doing so helped create a dense buffer that inhibits passage of Canada geese from the lake onto the golf course.

 

Asbury Park Boat Launch Shoreline Stabilization

Princeton Hydro developed a bio-engineering design for the stabilization of a badly eroded 250-foot segment section of shoreline adjacent to the Asbury Park boat launch. Coir fiber logs were used in conjunction with native plant material. As with the CTGC planting, help was provided by local volunteers and the DLC commissioners. The final element of the project involved the construction of a bioretention rain garden to control the runoff from the boat launch parking area. Signage was also installed to inform the public about the project and the benefits of shoreline naturalization.

 

The Deal Lake Watershed Protection Plan Implementation Project proved that despite Deal Lake being located in a highly urbanized watershed, it is possible to implement cost-effective green infrastructure and stormwater retrofit solutions capable of significantly decreasing pollutant loading to the lake.  These measures are part of the DLC’s continued efforts to utilize environmentally sustainable techniques to improve the lake’s water quality. This project won a North American Lake Management Society Technical Merit Award.

For more information about this and other Princeton Hydro projects, please contact us!