SW3240204_Supplement-EZ Form_20240402

LOW DENSITY
DESIGN REQUIREMENTS FOR LOW DENSITY PROJECTS FROM 02H.1003
1 Is project below density thresholds set forth in the applicable stormwater rule? Yes
2 Does project maximize dispersed flow and minimize channelization of flow? Yes
3 Has the use of piping been minimized per.1003(2)(c)? Yes
4 Side slopes of the vegetated conveyances(H:V) 3:1
5 Maximum velocity in the vegetated conveyances during the 10-year storm? 4.7
6 Are curb outlet swales proposed? No
7 Maximum longitudinal slope of curb outlet swale(s)(%) n/a
8 Bottom width of curb outlet swale(s)(feet) n/a
9 Maximum side slope of curb outlet swale(s)(H:V) n/a
10 Minimum length of curb outlet swale(s)(feet) n/a
11 Are treatment swales used instead of curb outlet swales? No
12 Is stormwater released at the edge of the setback as dispersed flow? Yes
13 Have stormwater outlets been designed to prevent downslope erosion? Yes
14 Are variations to rule.1003 proposed? No
ADDITIONAL INFORMATION
15 Please use this space to provide any additional information about this low density project:
A permanent conveyance swale has been designed to convey on-site and off-site runoff to the receiving stream.In general,the
project drainage patterns have been designed to mimic the existing drainage patterns.The site has been designed to use natural
conveyances in lieu of storm drainage curb and gutter.Please refer to Appendix C for supporting calculations for the permanent
conveyance swale.The drainage area size and peak flow were developed using USGS StreamStats,and backchecked using
available topographic and aerial imagery.
Drainage Pervious
Swale BUA Q Slope Venow Va«�ai Flow depth
Area area
(ac) (cfs) (%) (fps) (fps) (ft)
(ac) (ac)
1 18.70 1.67 17.03 0.39 27.00 1.70 16.00 4.70 1.40
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