1. The design of all regulated activities shall include the following steps in sequence to minimize stormwater impacts.
A. The applicant is required to find practicable alternatives to the surface discharge of stormwater and the creation of impervious surfaces and the degradation of waters of the Commonwealth, and the applicant shall maintain as much as possible the natural hydrologic regime of the development site.
B. An alternative is practicable if it is available and capable of being done after taking into consideration cost, existing technology and logistics in light of overall project purposes.
C. All practicable alternatives to the discharge of stormwater are presumed to have less adverse impact on quantity and quality of waters of the Commonwealth unless otherwise demonstrated.
2. The applicant shall demonstrate that it designed the regulated activities in the following sequence to minimize the increases in stormwater runoff and impacts to water quality:
A. Prepare an Existing Resource and Site Analysis Map (ERSAM), showing environmentally sensitive areas including, but not limited to, steep slopes, ponds, lakes, streams, Wetlands, hydric soils, vernal ponds, floodplains, buffer areas, hydrologic soil groups A and B (areas conducive to infiltration), any existing recharge areas and any other requirements outlined in the SALDO [Chapter 22].
B. Establish buffers according to §223.
C. Prepare a draft project layout avoiding earth disturbance in sensitive areas identified in §222(2)(A) and minimizing total site earth disturbance as much as possible. The ratio of the disturbed area to the entire parent tract area and measures taken to minimize earth disturbance shall be included on the ERSAM.
D. Identify development site specific predevelopment drainage areas, discharge points, recharge areas to be preserved and hydrologic soil groups A and B to be utilized for recharge.
E. Evaluate Nonstructural Stormwater Management Alternatives.
(1) Minimize earth disturbance.
(2) Minimize impervious surfaces.
(3) Break up large impervious surfaces.
F. Satisfy water quality and streambank erosion protection objective (§223).
G. Satisfy groundwater recharge (infiltration) objective (§224) and provide for stormwater treatment prior to infiltration.
H. Determine what management district the development site falls into (Appendix D) and conduct a predevelopment runoff analysis.
I. Prepare final project design to maintain predevelopment drainage areas and discharge points, to minimize earth disturbance and impervious surfaces, and to reduce runoff to the maximum extent possible.
J. Conduct a post development runoff analysis based on the final design and to meet the release rate and in turn the overbank flow and extreme event requirements (§225).
K. Manage any remaining stormwater runoff through treatment prior to discharge, as part of detention, bioretention, direct discharge or other structural control. (Ord. 181, 10/11/2006, §302)