Restoring Ballinger Lake Dam in Medford Lakes, NJ

Medford Lakes is a borough in Burlington County, New Jersey that consists of 22 lakes, and more than 10% of the homes there are log cabins. Located just 25 miles east of Philadelphia, within the New Jersey Pinelands Commission Management Area, the Borough is overseen by the Medford Lakes Colony (MLC), a homeowners association that manages social events and recreation activities for the community and also manages its “Lake Restoration Fund.” All homeowners in the community contribute to the Fund, which is used to manage and monitor lake water quality and maintain water control structures like dams and culverts.

Medford Lakes and its surrounding neighborhoods contain approximately 60 dams. The MLC retained Princeton Hydro to provide various engineering services for multiple dam structures throughout the Borough, including periodic visual inspections, dam breach and inundation analysis, and maintenance and repair work.

Ballinger Lake, located at the intersection of Lenape Trail and Stokes Road, contains a dam that is registered as a Class I – High Hazard Dam with NJDEP Division of Dam Safety. Immediately downstream from the dam is Main Street Medford Lakes, a congested portion of the Medford Lakes Borough.

The dam, originally constructed in the 1920s, is an earthen embankment dam with a clay core. Between 2000 – 2001, a reconstruction project took place that included the creation of both a primary and auxiliary spillway and a concrete culvert. The primary spillway consists of a concrete drop box and culvert that passes through the embankment. The auxiliary spillway, armored with articulated concrete block, is a low point on the embankment along Stokes Road.

In 2008, the Ballinger Lake Dam was inspected by Princeton Hydro and the NJDEP, Division of Dam Safety. The results of these inspections revealed considerable seepage at one of the concrete joints within the concrete culvert, a non-compliant trash rack assembly, a distressed gate valve assembly, and unstable downstream conditions.

Under Princeton Hydro’s direction, the lake was lowered to reduce the hydraulic load on the dam and to facilitate the required remediation and repairs. Princeton Hydro provided full turn-key engineering services that encompassed the development of the engineering documents and plans and preparation of all the permitting requirements (NJDEP Dam Safety, Pinelands Commission Certificate of Filing (CoF), NJDEP Dam Safety Emergency Permit, Burlington County Soil Conservation Erosion and Sediment Control, and NPDES permits). Our team also prepared the contractor bid specifications and provided construction oversight and management throughout the course of the repairs.

Throughout this process, Princeton Hydro completed multiple studies to characterize the hydraulic, hydrologic, structural, stability, geotechnical, and groundwater conditions at the dam under pre and post-repair conditions. The team eliminated the leakage and brought the dam back into compliance.  In 2019, MLC contracted Princeton Hydro to perform additional maintenance and improvements to the Ballinger Lake Dam spillway, outfall, and sluice gate.

The scope of work for the 2019 engineering and construction project included the following:

  • Replacement of the failed sluice gate structure
  • Installation of a baffled culvert extension on the downstream side of the existing culvert
  • Regrading of the downstream embankment to a shallower, uniform 3H:1V slope
  • Regrading of the levee crest to a uniform elevation
  • Riprap armament of the downstream channel
  • Various repairs to joints and spalls within the existing concrete dropbox and culvert structures.

The photo above, taken on September 23, 2019 by Princeton Hydro, shows a view of the lowered lake level and pumping intake hose.

Construction began on September 19, 2019 with the lowering of Ballinger Lake to facilitate the work within the existing dropbox structure. The lake lowering process was performed by a 6-inch centrifugal pump, which discharged water into the downstream channel. The photo above, taken on September 23, 2019, shows a view of the lowered lake level and pumping intake hose. After the lake was lowered below the dropbox crest, all of the concrete was power washed and work began to waterproof and repair all of the joints within the culvert.

The above photo, taken on October 17, 2019 by Princeton Hydro, shows the riprap being removed from the stream bed prior to pouring the flowable fill concrete mud mat.

In October, the team began removing portions of the existing stream bed riprap in preparation for pouring a flowable fill-based mud mat to level the foundation of the culvert extension. The area was dewatered with a submersible pump, with the discharge filtered through a sediment bag and directed back into the downstream channel at a point upstream of the installed turbidity barrier. The above photo, taken on October 17, 2019, shows the riprap being removed from the streambed prior to pouring the flowable fill concrete mud mat.

The above photo taken by Princeton Hydro shows the grate being prepared for the installation of the sluice gate valve operating mechanism.

The installation of the sluice gate valve support structure began in November 2019. Princeton Hydro oversaw the process to ensure the installation was being completed according to the design drawings and NJDEP Dam Safety regulations. The above photo taken by Princeton Hydro shows the grate being prepared for the installation of the sluice gate valve operating mechanism.

Photo taken on December 5, 2019 by Princeton Hydro showing the soil erosion mat being installed.

In December 2019, the team completed a topsoil application, seeding, and soil erosion matting installation to all disturbed areas of the site. All areas disturbed by construction activities (approximately 6,400 square feet) were graded to pre-construction conditions. The topsoil was applied to these areas and hand-raked to re-establish the original grades. The area was then seeded with perennial ryegrass, fertilized, and covered with a soil erosion mat. The above photo, taken on December 5, 2019, shows the soil mat being installed.

Following the final site inspection performed by Princeton Hydro in April 2020, we completed the Ballinger Lake Dam Spillway & Sluice Gate Improvements Closeout Report and presented it to MLC. The report confirmed that the site was considered stabilized in accordance with the approved project plans, the Standards for Soil Erosion and Sediment Control in New Jersey, and all NJDEP Bureau of Dam Safety requirements.

Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of dozens of small and large dams in the Northeast. Click below to read about an emergency repair we completed on the Lake Wauwauskashe Dam. A concerning blockage developed in Lake Wauwauskashe Dam’s spillway and water was backing up at the upstream outlet structure causing a number of issues and potential hazards. Medford Lakes Colony, Princeton Hydro, and other project partners employed innovative solutions that lead to a successful emergency repair.

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

To learn more about our dam and barrier engineering services, visit bit.ly/DamBarrier.

 

Dam Safety Recommendations for Tropical Storm Isaias

Tropical Storm Isaias Forecast. Source: NOAA

We, at Princeton Hydro, care for the health, safety, and well-being of our clients. We are tracking Tropical Storm Isaias closely as it heads up the East Coast, and the most recent precipitation forecast by NOAA is calling for a significant amount of rainfall in the NJ, PA, MD, NY region. Please be advised that the predicted precipitation could potentially pose a risk to your dam, pond, basin, or other structures.

For our clients who own and/or operate dams, levees, and other flood management structures, please take the following precautions, as adopted from a statement issued today by NJDEP Division of Dam Safety and Flood Engineering (see below), seriously:

  • For high/significant hazard dams, check your Emergency Action Plan to ensure that all contacts for emergency notification and emergency resources (engineers, contractors, supplies, etc.) are up to date.
  • Please refresh yourself regarding the dam owner’s responsibilities in the event of an emergency.
  • Please monitor your dam before, during, and after the storm event and report any concerns to your state Dam Safety office.
  • Prior to the storm, please take precautions to ensure that all spillways are clear of debris and that floating objects (boats, floating docks, etc.) which could block a spillway during high flow events are secured, where possible.
  • If you discover that a potential emergency condition exists at the dam, you should immediately contact your state Dam Safety office and the state emergency hotline. You must also contact your engineer, as well as implement your emergency action plan.
  • If your dam has any known vulnerabilities that you wish to discuss in advance of the storm, we recommend that you first contact your engineer. No modifications should be made to the dam without approval from your state Dam Safety office.

If you are a Princeton Hydro client and we provide inspection services to your dam, please reach President Geoffrey Goll, P.E. directly if you have any issues and/or concerns at 908-237-5660 ext. 103 or ggoll@princetonhydro.com. Even if it is after hours and you are concerned about the condition of your dam during this storm event, please do call Geoff directly. Safety is our priority and will do our best to assist you immediately.


State Dam Safety & Emergency Hotline Phone Numbers:

New Jersey:

  • NJDEP Division of Dam Safety and Flood Engineering: 609-984-0859
  • NJDEP Emergency Hotline 1-877-WARNDEP (1-877-927-6337)

New York:

  • NYSDEC, Division of Water, Bureau of Flood Protection and Dam Safety: 518-402-8185

Pennsylvania:

  • PADEP, Bureau of Waterways Engineering and Wetlands, Division of Dam Safety: 717-787-3411
  • PADEP Emergency Hotline: 1-800-541-2050

Maryland:

  • MDE, Water and Science Administration, Dam Safety Division: 410-537-3538
  • MDE’s Emergency Response Division: (866) 633-4686

Connecticut:

  • CT DEEP, Dam Safety Regulatory Program: 860-424-3706
  • DEEP’s Emergency Response Unit: 866-DEP-SPIL (866-337-7745) or 860-424-3338

***IMPORTANT MESSAGE FROM NJDEP***

DAM SAFETY PRECAUTIONS DURING TROPICAL STORM ISAIAS
POSTED: AUGUST 3,  2020 at 9:30 AM

 

This message is from the NJDEP, Division of Dam Safety & Flood Engineering. Based on weather forecasts, it has been determined that the potential for a significant rainfall event exists in the area of your dam. At this time, we are reminding high/significant hazard dam owners to check your Emergency Action Plan to ensure that all contacts for emergency notification and emergency resources (engineers, contractors, supplies, etc.) are up to date. Please also take a moment to refresh yourself regarding the dam owner’s responsibilities in the event of an emergency.

 

Please monitor your dam before, during, and after the storm event and report any concerns to this office. Prior to the storm, please take precautions to ensure that all spillways are clear of debris and that floating objects (boats, floating docks, etc.) which could block a spillway during high flow events are secured, where possible. If you discover that a potential emergency condition exists at the dam, you should immediately contact this office and our 24-Hour DEP Hotline at 1-877-WARNDEP (1-877-927-6337). You must also contact your engineer, as well as implement your emergency action plan.

 

If your dam has any known vulnerabilities that you wish to discuss in advance of the storm, we recommend that you first contact your engineer. You may also contact our office at the number below. No modifications should be made to the dam without approval from this office.

 

Please also be advised that the Division of Dam Safety and Flood Engineering does NOT recommend or require the lowering of impoundments prior to, during, or immediately following a storm event unless the integrity of the dam is in question. If a dam owner chooses to lower an impoundment for any reason, we encourage them to coordinate with local and county emergency management officials to ensure that any increased flow as a result of the lowering does not create flooding conditions downstream of the dam. The dam owner must also coordinate with the Division of Freshwater Fisheries (908-236-2118). A lake lowering permit (issued by Division of Freshwater Fisheries) is usually required prior to lowering.

 

Division of Dam Safety & Flood Engineering
NJ Department of Environmental Protection
609-984-0859

 

Click here for more information about Tropical Storm Isaias, visit NOAA’s National Hurricane Center and Central Pacific Hurricane Center.

Upcoming Environmental Education Opportunities

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

May 7 – May 11: NJWEA 103rd John J. Lagrosa Conference & Exposition

The New Jersey Water Environment Association Conference is the largest water-focused environment exposition in the Northeast drawing participants from throughout the country for four days of workshops, educational sessions, networking events, exhibitor booths and more.

Princeton Hydro Founder Dr. Stephen Souza is giving a presentation on ”Increased Storm Resiliency through the Application of Green Infrastructure BMPs.”

See the conference program.

May 18: Restoration Ecology One-Day Course

This Rutgers Office of Continuing Professional Education course, led by Dr. Stephen Souza, explores the use of mitigation and sustainable design techniques to reduce stormwater impacts and increase storm resiliency.

Designed for those involved in the recovery of impacted river, lake, riparian, wetland and coastal environments, the course will draw heavily upon real-world examples of restoration ecology in practice, and will cover topics, including green infrastructure stormwater techniques; FEMA’s national flood insurance program community rating system (the course is approved for certified Floodplain Manager credits); reconnecting streams to their floodplains; stream daylighting; and more. The course will take place at Duke Farms.

Get more info and register.

June 4 – 6: Association of State Dam Safety Officials Northeast Regional Conference

The conference program will focus on issues of importance to dam owners, government officials and engineers in the northeast region with applicability to the greater dam and levee safety community as well.  Both general and concurrent technical sessions, timely panel discussions, an informative exhibit show, and networking opportunities with colleagues from across the region highlight this event.

Princeton Hydro is giving two presentations:

Get more info and register.

June 6: Camden Environmental Summit

The Camden Environmental Summit provides an opportunity for community groups, nonprofit organizations, environmental leaders, and government officials to come together to explore equitable and creative solutions to climate change in the Camden region. Educational breakout sessions include topics like stormwater management, climate resilience, brownfields redevelopment, illegal dumping and improving the overall health of the watershed.

Get more info and register.

June 8: Sustainable Raritan River Summit

The 10th Annual Sustainable Raritan River Conference and Awards Ceremony is titled “Micro to Macro: The Future of the Raritan.” Conference participants will explore emerging contaminants affecting the Raritan and discuss watershed planning efforts that address threats to achieving a fishable and swimmable status for the Raritan River, basin and bay.

The annual conference typically draws 200+ attendees from state, local and federal government, non-profit organizations, businesses, philanthropic organizations, academia, and individuals committed to a more sustainable Raritan.

Get more info and register.

 

Stay tuned for more!

The Restoration of Bound Brook

To the delight of fish and environmentalists alike, an important step has been made in the removal of the aging spillway of Hunters Pond Dam in Scituate and Cohasset, Massachusetts. The spillway was notched to ensure a gradual release of water from the impoundment, letting Bound Brook flow free again after being dammed for centuries.

As the first barrier upstream from the Atlantic Ocean, the dam’s removal restores 5-miles of river spawning ground and habitat for alewife, blueback herring, American eel, rainbow smelt, sea lamprey and other important species. The removal of Hunters Pond Dam also reduces the threat of dam failure.

Princeton Hydro is proud to be working on this project with T Ford Company, U.S. Fish and Wildlife Service, and many other great partners. The project is funded by grants from the Massachusetts Department of Ecological Restoration and the NOAA.

The project also includes rebuilding a culvert, removing a concrete spillway, and replacing a water main. Stay tuned for more!