Project Example:

Live Cribwall Construction along Peapack Brook
Peapack & Gladstone Township, Somerset County, NJ
Client: Upper Raritan Watershed Association

ASGECI was contracted by Upper Raritan Watershed Association (URWA) to evaluate a badly eroded section of the Peapack Brook Shoreline, located within Rockabye Meadow Park, in the Town of Peapack Gladstone, Somerset County, NJ.

The Peapack Brook is a gently flowing stream under normal base flow conditions; however, during storm events the Peapack Brook becomes a raging torrent. The erratic flow has resulted in severe bank erosin, an incised stream bed, and changes in stream morphology. URWA contracted with ASGECI to restore a sheer, unvegetated section of streambank approximately 135 feet in length and a 5 to 6 foot height on the outer bend of a meander. The project area includes wetlands, wetland transition areas and State open waters regulated under the Freshwater Wetlands Protection Act Rules (N.J.A.C. 7:7A), and is also located within the Flood Hazard Area (100 year floodplain) regulated under the Flood Hazard Control Act Rules (N.J.A.C. 7:13).

The Peapack Brook provides habitat to native brook trout (Salvelinus fontinalis) and the NJ State Threatened wood turtle (Glyptemys insculpta). Because flows are high during storm events and the erosion was so severe, ASGECI determined that a relatively permanent structure would be required to stabilize this bank and prevent the eventual undermining of an adjacent sanitary force main. The installation of a "live cribwall" structure was selected as the preferred method to stabilize this portion of the Peapack Brook. A live cribwall provides effective, immediate protection of steep eroded banks and hastens the rapid establishment of woody vegetation and habitat.

ASGECI performed a field investigation within the project site and delineated wetlands and State open waters. The project site and natural features were then surveyed. ASGECI worked closely with Kinsey Associates and prepared project design plans. ASGECI prepared and submitted to NJDEP successful applications for a Combined Wetland General Permit No. 20 for stream bank stabilization and Flood Hazard Area Permit (GP# 20A) to authorize the installtion of the live cribwall. The permits included construction timing limitations due to the presence of trout and wood turtle. ASGECI subsequently constructed the 135 foot length live cribwall during April/May 2007. Live stakes, including black willow, pussy willow, silky dogwood and red-osier dogwood, were installed along the face of the cribwall and native species of trees and shrubs were used to naturalize the top of the cribwall. The live cribwall is currently functioning as designed.