A. Stormwater management practices minimize runoff and increase infiltration which recharges groundwater and improves water quality. Implementing stormwater best management practices into the landscape and grading design plans to minimize runoff and to increase on site rainwater retention and infiltration are encouraged.
B. Project applicants must refer to the local agency or regional water quality control board for information on any applicable stormwater technical requirements.
C. All planted landscape areas are required to have friable soil to maximize water retention and infiltration. (Refer to subsection 15-15A-5D of this chapter.)
D. It is strongly recommended that landscape areas be designed for capture and infiltration capacity that is sufficient to prevent runoff from impervious surfaces (i.e., roof and paved areas) from either: 1) the 1-inch, 24-hour rain event or 2) the eighty fifth percentile, 24-hour rain event, and/or additional capacity as required by any applicable local, regional, state or federal regulation.
E. It is recommended that stormwater projects incorporate any of the following elements to improve on site stormwater and dry weather runoff capture and use:
1. Grade impervious surfaces, such as driveways, during construction to drain to vegetated areas.
2. Minimize the area of impervious surfaces such as paved areas, roof and concrete driveways.
3. Incorporate pervious or porous surfaces (e.g., gravel, permeable pavers or blocks, pervious or porous concrete) that minimize runoff.
4. Direct runoff from paved surfaces and roof areas into planting beds or landscaped areas to maximize site water capture and reuse.
5. Incorporate rain gardens, cisterns, and other rain harvesting or catchment systems.
6. Incorporate infiltration beds, swales, basins and dry wells to capture stormwater and dry weather runoff and increase percolation into the soil.
7. Consider constructed wetlands and ponds that retain water, equalize excess flow, and filter pollutants.
F. Landscape areas containing artificial turf or synthetic grass must be permeable and must not contain lead or other toxic chemicals which can pollute groundwater or the storm drain system. (Ord. 1515, 12-15-2015)