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APPENDIX B – WAKE COUNTY PROGRAMS TO MITIGATE SECONDARY AND CUMULATIVE IMPACTS
B-16
applied to cluster and open-space subdivisions, if overall density does not exceed one lot
per acre. WSW Overlay District WS-IV, which is in the Jordan Lake Watershed,
impervious surface limitations of 24 percent are applied, but these impervious surface
limits are not applied to cluster and open-space subdivisions if the development is
served by curb-and-gutter residential lots of at least 20,000 square feet in area, and
cluster subdivisions with an overall lot density of no more than 2 lots per acre. These
policies ensures that low-impact development and conservation subdivisions, which
help maintain the predevelopment hydrograph, are not discouraged.
B.7
Erosion and Sediment Control
Erosion and sediment control requirements are presented in Article 10 of the County’s
UDO. Erosion and sediment control plans must be submitted for activities that disturb
more than 1 acre. The Erosion and Sediment Control Program has eliminated a
substantial amount of sediment transport to local streams.
Wake County has six objectives for the Erosion and Sediment Control Program:
Identify critical areas that are subject to severe erosion and ensure they receive
special attention.
Limit time of exposure to shortest feasible time.
Limit exposed area – plan and conduct activities to minimize the size of the area to
be exposed at any one time.
Control surface water originating upgrade of exposed areas to reduce erosion and
sediment loss during the exposure period.
Control sedimentation to prevent offsite damage from sedimentation.
Manage stormwater runoff -control the velocity at the point of discharge to minimize
erosion of the site and increased sedimentation of the stream.
Wake County’s sediment and erosion control practices support an overall stream
protection plan by limiting in-stream suspended sediment and sediment deposition.
Erosion and sediment control strategies are discussed at pre-construction conferences
through the permit and plan approval processes. These processes also allow for the
review of stormwater controls. A pre-construction conference provides the County with
an opportunity to educate developers about the requirements for effective erosion and
sediment control.
The County requires the use of the proven latest technology related to erosion and
sediment control practices in sediment and erosion control plans. The sediment and
erosion control plans usually will include a sediment basin, which is sized according to
the drainage area. Silt fences and construction entrances are required on all sites, even
those that fall under the 1-acre threshold for requiring an erosion and sediment control
plan.