NEWS
used to remove sheet piling driven deep into bedrock. If the area upstream of the dam, the impoundment, contains a large amount of sediment, then it may need to be dredged before the dam is removed. Equipment for dredging varies depending on whether dredged materials will stay on site or be transferred offsite. Again, depending on specific conditions, dredging can be done mechanically or hydraulically. In addition to removing the dam, restoration to shape new banks and create habitats might entail controlling the grade of the new river channel. Moving around on the soft ground of the former impoundment or newly formed banks requires “swamp” mats. These 4’ x 20’ timber or steel mats are placed to allow heavy equipment to move through soft areas. The excavator must “leapfrog” (lifting mats from behind to in front of the machine) across the mats as the machine moves forward. An articulating off-road truck, common on excavation sites, is often used for dam removal projects. A “crawler hauler” with rubber tracks can be used on a dam removal if material needs to be moved within the former impoundment and the ground is too soft for the off-road truck. As you might imagine, an experienced operator with a knack for river work is more important than all this specialized equipment combined. Sometimes the river is diverted during demolition; however, in a smaller river—the most typical site for a New Jersey dam removal—the operator is working in a flowing stream. Even the most skilled operators from other disciplines may find it too challenging to adapt to work in rivers and streams; they might be
An excavator constructs rock vanes specially designed to allow migratory fish to pass under Interstate 80.
unable to anticipate changes in weather and their resulting impact on the depth and speed of water. Such inexperience can lead to swamped or damaged equipment and other safety concerns that no one wants as part of a job. For the best results, and results that hold up to all types of weather, an experienced contractor is your most important asset. Dam removal projects are complicated but exciting and important projects—so much so that a collaboration of nonprofits and government agencies came together to form the Statewide Dam Removal Partnership (SDRP), which seeks to advance the removal of antiquated, dangerous, or ecologically detrimental dams. SDRP maintains a website, njdams.org, which acts as a clearinghouse for New Jersey specific dam removal information. An email sent via
78 Utility & Transportation Contractor | february| 2021
the site can connect you to someone with the expertise you need to solve a particular problem as you approach a dam removal project. SDRP members meet quarterly to discuss beneficial dam removal projects and to exchange information regarding policy, regulatory issues, funding, and the practical considerations of dam removal.
Two excavators, one fitted with a hydraulic hammer and one fitted with a bucket and thumb, work side by side to remove a dam.
The SDRP holds periodic training workshops for professionals and officials and provides information to the public about how dams and dam removal may affect their communities and their lives. With the vast majority of New Jersey’s aging dams no longer performing the function for which they were built, dam removal projects are likely to become more common. Removal projects being bid by a commercial owner would likely appear on a site like cisleads.com, bidclerk.com, or bidcentral.com, while jobs run by federal, state, or local governments would be found on cisleads. com, NJstart.gov, or beta.sam.gov. Requests for proposals by nonprofit organizations might be issued through a site like bidclerk. com or might be included in a press release announcing an upcoming project. Additionally, American Rivers, a nationwide nonprofit, maintains a list of certified Master Service Contractors often used by river restoration project teams who are preparing an RFP. Contractors can request information on the certification process by contacting restorationrfq@americanrivers.org. The Nature Conservancy is excited for this opportunity to reach UTCA members and possibly grow the number of firms that are interested in restoration projects.
