(A) Purpose and findings. These regulations are designed to:
(1) Ensure that the design of streets conforms to the recommendations of the Comprehensive Plan;
(2) Provide for the safety for both vehicular and pedestrian traffic;
(3) Provide for livable residential and commercial environments;
(4) Provide economy of land use, construction and maintenance; and
(5) Provide safe and efficient access to property. Unlike the situation in traditional subdivision regulations, one intent of this section is to permit narrower street widths while requiring greater connectivity in order to more efficiently disperse traffic, to protect pedestrians from high vehicular speeds and to enhance the streetscape. The city further finds and determines that street layout and design can have a very significant influence on the total imperviousness and hydrology of a site. Alternative road layout can result in significantly reducing imperviousness, reducing storm water run-off, protecting water quality and providing cost savings for developers and home buyers.
Slope % | Local W = 30 feet | Subcollector W = 40 feet | Collector W = 44 feet | Secondary (with median) Maximum Water Depth = 7 Inches W = 24 feet Minimum and 29 Feet Maximum | Primary and Secondary (without median) Water Depth = 7 Inches W = 24 Feet Minimum and 29 Feet Maximum | |||||
Q cfs | V f/s | Q cfs | V f/s | Q cfs | V f/s | Q cfs | V f/s | Q cfs | V f/s | |
Slope % | Local W = 30 feet | Subcollector W = 40 feet | Collector W = 44 feet | Secondary (with median) Maximum Water Depth = 7 Inches W = 24 feet Minimum and 29 Feet Maximum | Primary and Secondary (without median) Water Depth = 7 Inches W = 24 Feet Minimum and 29 Feet Maximum | |||||
Q cfs | V f/s | Q cfs | V f/s | Q cfs | V f/s | Q cfs | V f/s | Q cfs | V f/s | |
0.40 | 35.4 | 2.8 | 47.8 | 2.9 | 44.1 | 2.7 | 20.6 | 2.5 | 19.2 | 2.3 |
0.45 | 37.5 | 3.0 | 50.7 | 3.0 | 46.8 | 2.8 | 21.9 | 2.7 | 20.4 | 2.4 |
0.50 | 39.6 | 3.2 | 53.4 | 3.2 | 49.3 | 3.0 | 23.1 | 2.8 | 21.5 | 2.5 |
0.55 | 41.5 | 3.3 | 56.0 | 3.4 | 51.7 | 3.1 | 24.2 | 2.9 | 22.5 | 2.7 |
0.60 | 43.3 | 3.5 | 58.5 | 3.5 | 54.0 | 3.3 | 25.3 | 3.1 | 23.6 | 2.8 |
0.65 | 45.1 | 3.6 | 60.9 | 3.7 | 56.2 | 3.4 | 26.3 | 3.2 | 24.5 | 2.9 |
0.70 | 46.8 | 3.8 | 63.2 | 3.8 | 58.4 | 3.5 | 27.3 | 3.3 | 25.4 | 3.0 |
0.75 | 48.5 | 3.9 | 65.4 | 3.9 | 60.4 | 3.7 | 28.3 | 3.4 | 26.3 | 3.1 |
0.80 | 50.0 | 4.0 | 67.6 | 4.1 | 62.4 | 3.8 | 29.2 | 3.5 | 27.2 | 3.2 |
0.85 | 51.6 | 4.1 | 69.6 | 4.2 | 64.3 | 3.9 | 30.1 | 3.7 | 28.0 | 3.3 |
0.90 | 53.1 | 4.3 | 71.7 | 4.3 | 66.2 | 4.0 | 30.9 | 3.8 | 28.8 | 3.4 |
0.95 | 54.5 | 4.4 | 73.6 | 4.4 | 68.0 | 4.1 | 31.8 | 3.9 | 29.6 | 3.5 |
1.00 | 55.9 | 4.5 | 75.5 | 4.5 | 69.8 | 4.2 | 32.6 | 4.0 | 30.4 | 3.6 |
1.50 | 68.5 | 5.5 | 92.5 | 5.5 | 85.4 | 5.2 | 40.0 | 4.9 | 37.2 | 4.4 |
2.00 | 79.1 | 6.4 | 106.8 | 6.4 | 98.66 | .0 | 46.1 | 5.6 | 43.0 | 5.1 |
2.50 | 88.5 | 7.1 | 119.4 | 7.2 | 110.3 | 6.7 | 51.6 | 6.3 | 48.1 | 5.7 |
3.00 | 96.9 | 7.8 | 130.8 | 7.8 | 120.8 | 7.3 | 56.5 | 6.9 | 52.7 | 6.2 |
3.50 | 104.7 | 8.4 | 141.3 | 8.5 | 130.5 | 7.9 | 61.0 | 7.4 | 56.9 | 6.7 |
4.00 | 111.9 | 9.0 | 151.1 | 9.1 | 139.5 | 8.5 | 65.2 | 7.9 | 60.8 | 7.2 |
4.50 | 118.7 | 9.5 | 160.2 | 9.6 | 148.0 | 9.0 | 69.2 | 8.4 | 64.5 | 7.6 |
5.00 | 125.1 | 10.0 | 168.9 | 10.0 | 156.0 | 9.5 | 72.9 | 8.9 | 68.0 | 8.0 |
5.50 | 116.0 | 10.0 | 153.0 | 10.0 | 163.6 | 9.9 | 76.5 | 9.3 | 71.3 | 8.4 |
6.00 | 108.0 | 10.0 | 143.0 | 10.0 | 157.0 | 10.0 | 79.9 | 9.7 | 74.5 | 8.8 |
6.50 | 102.0 | 10.0 | 134.0 | 10.0 | 148.0 | 10.0 | 81.0 | 10.0 | 77.5 | 9.1 |
7.00 | 96.0 | 10.0 | 127.0 | 10.0 | 140.0 | 10.0 | 76.0 | 10.0 | 80.4 | 9.5 |
7.50 | 91.0 | 10.0 | 120.0 | 10.0 | 132.0 | 10.0 | ||||
8.00 | 87.0 | 10.0 | 115.0 | 10.0 | 126.0 | 10.0 | ||||
8.50 | 83.0 | 10.0 | 110.0 | 10.0 | 120.0 | 10.0 | ||||
9.00 | 79.0 | 10.0 | 105.0 | 10.0 | 115.0 | 10.0 | ||||
9.5 | 76.0 | 10.0 | 101.0 | 10.0 | 111.0 | 10.0 | ||||
NOTES TO TABLE: Manning’s “n” = 0.018; W = width of ponded water; Q cfs = design flow in cubic feet per second; and V f/s = velocity feet per second. Note to reader: This table should be modified for local conditions. | ||||||||||
Street Classification | Standard |
Alleys or TND trails, alleys and lanes | Alleys and TND trails, alleys, and lanes shall be designed for 5-year frequency within the limits of the alley pavement/curbs and 25-year frequency within the right-of-way/easement to carry storm water. |
Collector streets or main streets with more than 34 feet of pavement width | A maximum flow depth to the top of curb on a subcollector and collector street is permitted during a 25-year storm event. |
Local streets or TND avenues and main streets with less than 34 feet of pavement width | Five-year frequency design basis. A 25-year frequency storm must be contained within the street right-of-way. |
Primary and secondary arterial streets or traditional neighborhood development (TND) boulevard/parkway | One lane in each direction on arterial streets shall remain passable with a flow depth not to exceed 0.30 feet during a 25-year storm event. The maximum depth of water in the street section shall not exceed 7 inches. |
(B) Applicability.
(1) This section applies to:
(a) Any application for subdivision plat approval;
(b) Any application for site plan approval if no subdivision plat is required; and
(c) Any ministerial development approval where required by subsection (B)(2) below.
(2) The construction of standard curbs and sidewalks shall be a condition of the granting of a development approval, if:
(a) A new building or structure when curbing is in place or curb lines are established for a sidewalk; and
(b) A new or an additional driveway approach is required.
(Ord. 3020, passed 9-10-2013, § 5.23.1)