City of Dawsonville
Planning and Zoning, 415 Highway 53 East, Suite 100 | Dawsonville, GA 30534 | (706) 265‑3256 - 10/9/2019
35.______ Submit Stormwater Management Report. Exception is < 5,000 sqft of impervious cover and < 1 acre.
36.______ Stormwater Management Report must be approved prior to scheduling a plan sign-off.
37.______ Acreage of all off-site drainage areas contributing to flow thru the project. Show on plans or note if no off-site
drainage.
38.______ Plan and profile of all pipes including grade, type of pipe, 25-year HGL, elevations, proposed cover, manholes and
headwalls.
39.______ Minimum of 12" of compacted fill material required over all pipes. Prefer 2ft – top of pipe to top of finish pavement
- required over pipes under roadway.
40.______ Storm sewer slopes must be greater than or equal to 1%.
41.______ All storm drain pipes will be a minimum of 18" in diameter
42.______ All storm drain pipe must be concrete under pavement within right of way.
43.______ All CMP must be fully bituminous coated with paved invert filling corrugation for at least 25% of circumference.
44.______ All storm drain pipes with > fifteen (15) feet cover shall be concrete. > 15’ to < 20’ cover shall be Class IV. > 20’ cover
shall be Class V.
45.______ 100-Year upstream headwater elevation at pipes inlets to be shown by labeling elevation and outlining contour at
that elevation. This contour will be the drainage easement if it extends outside of the 20’ drainage easement.
46.______ Show details for all proposed storm drainage structures per GDOT or Manufacture of HDPE.
47.______ Pipe to discharge into natural draw or graded ditch with rip-rap ditch checks. Size rip rap aprons and provide
dimensions on plans, including apron depth.
48.______ Provide channel protection and/or permanent energy dissipation (in addition to rip-rap) at all outlets having a
discharge velocity greater than 5 fps or Froude Number greater than 2.5.
49.______ Provide complete pipe chart including pipe size, pipe gauge or class, time of concentration, runoff coefficient,
rainfall intensity, drainage area, and outlet velocity. Design for 25- year storm. The 50-year storm shall be used on live streams,
cross drains serving 20 acres or larger, and any pipe receiving off-site drainage.
50.______ Minimum 20’ storm drainage easement on all storm drain pipes, drainage swales and water courses receiving off-
site drainage.
51.______ Minimum 20' drainage/access easement from public right-of-way required for all stormwater facilities.
52.______ Retaining wall design must be submitted to the City of Dawsonville for approval prior to construction plan approval.
Wall design must include details and specifications that are site specific and must be signed and sealed by a registered
professional engineer in the State of Georgia. All walls greater than thirty (30) inches in height shall include a fence or handrail