The Canterbury Estates stormwater basin
Was designed to standards that have become outdated compared to modern Act 167 and the Department of Environmental Protection model stormwater ordinances.
The Canterbury Estates Water Quality Basin project involves the modification of the existing detention basin outlet structure to improve the facility’s ability to reduce the peak rate of stormwater runoff downstream, increase the stormwater retention volume, and inclusion of water quality enhancement features.
A significant amount of stormwater runoff currently bypasses the stormwater facility and creates flooding conditions downstream.
A secondary earthen berm will be constructed downstream of the existing detention basin to manage stormwater runoff from an expanded drainage area.
The secondary facility will reduce the total sediment, nitrogen, and phosphorus pollutant loads currently being discharged downstream.
McCormick Park bank regrading and stabilization
Would require a General Permit for Bank Rehabilitation (GP-3) and could be graded from the overbank and stabilized with erosion matting and native vegetation.
Proposed plantings or live staking would be utilized to encourage further stabilization and habitat creation.
The restoration approach at the McCormick Park site would roughly resemble the Concept Rendering shown in Figure 1, only along the left bank of the reach paralleling McCormick Rd.
Additional coordination with DEP outside of the scope of this study is recommended to confirm that this minor bank work would be applicable towards the load reduction requirements of the township’s PRP prior to moving forward.
The Spring Run stream restoration project
The establishment of floodplain benches.
Encourages the creation of wetlands and habitat, and an aesthetic enhancement of the waterway.
675 linear feet of actively eroding banks will be restored to significantly reduce the pollutant load being transported downstream (see cross-section below).
Excess sediment deposited in the historic floodplain areas will be removed to re-establish floodplain benches.
The floodplain benches will serve to reduce stormwater flow velocities and shear stresses during high flow events and allow for native vegetation to be reestablished.
It has been estimated that this project will prevent 30,000 pounds per year of sediment from being transported downstream.