What are examples of surfaces that would not be considered impervious or built upon area?

Surfaces such as a slatted deck, the water area of a swimming pool and pervious paving material that absorbs water and allows it to infiltrate through the material such as pervious asphalt or pervious concrete would not be considered impervious or built upon. Also, a surface of number 57 stone as designated by the American Society for Testing and Materials, laid at least four inches thick over a geotextile fabric, a trail that is either unpaved or paved as long as the pavement is porous with a hydraulic conductivity greater than 0.001 centimeters per second (1.41 inches per hour), landscaping material including but not limited to gravel, mulch, sand and vegetation placed on areas that receive pedestrian or bicycle traffic or on portions of driveways and parking areas that will not be compacted by the weight of a vehicle such as the areas between sections of pavement that support the weight of a vehicle shall not be considered as impervious area.

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1. What ordinance regulates Post Construction Stormwater Management in the City of Winston-Salem?
2. Are all developments subject to requiring a permit or providing post construction Stormwater management controls?
3. Does the City of Winston-Salem review plans for Post Construction Stormwater permitting in the County and in other municipal areas such as Clemmons, Kernersville etc.?
4. What developments or redevelopments are excluded from the City of Winston-Salem’s Post Construction Stormwater Management ordinance provisions and therefore would not be required to apply for a permit
5. What constitutes “substantial progress”?
6. What developments or redevelopments may be exempt from some, or all, of the provisions of the City of Winston-Salem’s Post Construction Stormwater Management ordinance?
7. Are there any development projects or activities that are not subject to this ordinance?
8. What developments or redevelopments are subject to adhering to some or all of the provisions of the post construction Stormwater management ordinance provisions?
9. When are the quality provisions of the ordinance applicable to developments that are not exempt or excluded?
10. When is a development considered low density and thus must only comply with the ordinance low density water quality provisions?
11. When is a development considered high density and thus must comply with the ordinance high density water quality provisions?
12. How is project density percentage determined?
13. When is a development subject to the water quantity provisions of the ordinance?
14. What constitutes impervious area or built upon area?
15. What are examples of surfaces that would not be considered impervious or built upon area?
16. Is existing impervious area required to be managed or treated?
17. What is the design manual that the City of Winston-Salem references and adheres to for Stormwater Management Plan designs?
18. What does SCM or BMP mean?
19. If a development is considered low density in regards to water quality is management required?
20. When and where do stream buffers apply and what are the requirements for such buffers?
21. What is considered a perennial or intermittent stream or conveyance?
22. If a development is considered high density in regards to water quality is management required?
23. What are some examples of primary SCM’s?
24. If a development exceeds 20,000 sq.ft. in net new impervious area and the water quantity provisions apply, is management required?
25. What constitutes a no adverse impact study?
26. The no adverse impact study must assess impacts to a suitable point downstream. Where or how far downstream is this point located?
27. If management is to be provided for quantity what are the design storm events that must be managed or attenuated?
28. What type of SCM’s can be used to attenuate for these quantity requirements?
29. Is there a variance procedure allowed for in cases where it’s impossible to treat or capture all proposed impervious area or in cases where for example its impossible not to avoid an impact to a buffe
30. Is there a financial surety required for permitted Stormwater management systems?
31. When and how is the developer’s surety amount determined?
32. When and how is the HOA or POA’s, whichever is applicable, cost for their future surety funds determined?
33. Is there an Operation and Maintenance Agreement required as part of permitting?
34. What constitutes an Operation and Maintenance (O&M) Agreement?
35. When is a Post Construction Stormwater Management permit issued?
36. Once a development that has a Stormwater management system construction is complete what does the owner/engineer have to do to continue to satisfy their permit?
37. How often must an owner inspect the system?
38. Who should carry out the inspections?
39. Are there any other Agreements other than an Operation and Maintenance Agreement required as part of permitting?