Boswell Engineering (Boswell) performed the bank stabilization design, permitting and construction inspection for an 800 lf. section of the Ramapo River in the Borough of Oakland, Bergen County, New Jersey. The nature of the emergency consisted of a severe erosion hazard along an 800 lf. section of the eastern bank of the Ramapo River. The project area began 200’ downstream of the confluence with Crystal Lake to approximately 600’ upstream of the Interstate 287 overpass. The cause of erosion along the eastern bank of the watercourse was a combination of unusual storm events (including Superstorm Sandy), erodible soils and changing stream dynamics as the Ramapo River attempted to reach equilibrium.
The severe erosion experienced along this portion of the channel was jeopardizing the safety and welfare of the residents along Lake Shore Drive and creating blockages of flow downstream. The excessive accumulation of sediment within the channel began to alter the geomorphology and dynamics of the watercourse, further exacerbating the problem. Additionally, the heavy sedimentation and vegetative debris constantly eroding into the channel was adversely affecting the water quality of the Ramapo River and disrupting downstream aquatic biota.
Due to the size and scope of the bank stabilization project, the Borough qualified for a community grant from the National Resource Conservation Service (NRCS). Boswell worked closely with the NRCS and the NJDEP Division of Land Use to design, bid and construct the project on an emergency basis to prevent the loss of additional property. The contractor was able to immediately establish the toe of the slope using rip rap stone providing the necessary level of protection for seasonal storm events and flash floods. The remainder of the project was completed in less than four months and involved the regrading of the slope, installation of an erosion control blanket and application of a temporary and permanent vegetative seed mixture.