(a) Proposed Grade. Grade line of proposed street construction must include the following:
(1) Percent of grade. The minimum grade for curb and gutter shall be not less than four-tenths percent (0.4%) or greater than ten percent (10%). Sidewalk grade shall not exceed twelve percent (12%) without use of steps.
(2) Elevations at beginning and end of all vertical curves.
(3) Length of vertical curves with elevations and stations of vertical points of intersection (VPI).
(4) Elevations computed every fifty feet on all tangent sections, and grades computed every twenty-five feet in all vertical curves. Grades to be computed at those minimum distances on all even stations; i. e., 00, plus 25 and plus 50.
(5) Elevations along all curbs and curb returns on intersecting streets. The grades of intersecting streets shall match at the intersection of the extensions of the respective curbs; in other words, a hypothetical curb. P.I. must be established.
(6) Elevations at all curb inlets.
(b) Centerline Extensions. Extend centerline profile 300 feet beyond property lines or boundary of all streets that provide for access to adjoining property.
(c) Existing Street Connection. When proposed street is an extension of, or connects with an existing street or road, show existing centerline profiles for 200 feet minimum distance to insure proper grade tie.
(d) Existing Street Intersection.
(1) When a proposed street intersects with an existing street or road, show centerline profile of existing street or road 300 feet minimum distance to right and left of proposed connection.
(2) Street intersections shall have 300 feet minimum sight distance.
(e) Vertical Curves. The following shall be used as a guide for minimum lengths of vertical curves located within a 50-foot right of way.
Algebraic Difference in % Grade | Length of Vertical Curve (feet) |
1.0 - 2.0 | 50 |
2.0 - 4.0 | 100 |
4.0 - 4.5 | 150 |
4.5 - 5.0 | 200 |
5.0 - 6.0 | 250 |
6.0 - 7.0 | 300 |
or 300 feet sight distance based on 3.75 feet height of eye and 6-inch object height.
(f) Different Curb Elevations. If a difference exists in elevations or proposed curb grades, identify curb elevations as: top of right curb and top of left curb.
(g) Cul-de-Sac Grade. Maximum centerline grade of permanent cul-de-sacs shall not exceed three percent (3%).
Grade profiles along the curb in cul-de-sacs to be computed along the back of curb starting at the beginning of the curb return, following the back of curb around the cul-de-sac, and then to the end of the return opposite the point of beginning. Grade ties of the proposed street before entering the cul-de-sac shall be shown on each end of the cul-de-sac grade profile to insure proper grade connection. Other approved methods may be used subject to the approval of the City. Minimum diameter shall be eighty feet.
(h) Storm Sewer. Storm sewer to be shown in profile with the following required information:
(1) Profile of existing ground at centerline of storm sewer.
(2) Profile of proposed finished grade.
(3) Percent of grade of proposed storm sewer.
(4) Size of proposed pipe or structure.
(5) Stations to be shown every 100 feet and at all appurtenances.
(6) Show curb inlets, inlets, etc., with proposed elevations for the tops and inverts, or tabulation in plan view may be permitted if all structures are identified.
(7) Show all existing stream crossings.
(8) Show compacted fill at all former stream crossings.
(9) Provide firm bearing for all storm sewer and appurtenances.
(i) Stream Profile. Profiles of streams that are not to be piped shall include:
(1) Profile of top of bank on both sides where difference in elevation exists.
(2) Profile of flow line (invert) of stream bed.
(3) Profile of computed water elevation.
(4) Where land included is subject to flood, cross sections, topography and spot elevation are required.
(j) Existing Ground. Show existing ground at centerline and proposed computed grade of invert on all streams where relocation of channel is proposed.
(k) End Slope. Provide 2:1 slope at the end of street construction with necessary easement shown on plan. (Ord. 85-11. Passed 4-1-85.)