(A) Blocks.
(1) Block length. In general, intersecting streets determining block lengths shall be provided at such intervals as to serve cross traffic adequately, and to meet existing streets. Where no existing plats control, the blocks in residential subdivisions shall normally not exceed 1,000 feet in length, except where topography, or other conditions, justify a departure from this maximum. In blocks longer than 800 feet, pedestrian ways, and/or easements, through the block may be required. The width and location of pedestrian ways shall be subject to the approval of the City Engineer and the Planning and Zoning Commission. Blocks for business, or industrial, use should normally not exceed 600 feet in length.
(2) Block width. The width of the block shall normally be sufficient to allow two tiers of lots of appropriate depth. Blocks intended for business, or industrial, use shall be of such width as to be considered most suitable for their respective use, including adequate space for off-street parking and deliveries.
(B) Streets and alleys.
(1) Thoroughfares and collector streets. The arrangement of thoroughfares and collector streets shall conform as nearly as possible to the comprehensive plan. Except for cul-de-sacs, streets normally shall connect with streets already dedicated in adjoining, or adjacent, subdivisions, or provide for future connections to adjoining unsubdivided tracts, or shall be a reasonable projection of streets in the nearest subdivided tracts. The arrangement of thoroughfares and collector streets shall be considered in their relation to the reasonable circulation of traffic, to topographic conditions, to runoff of stormwater, to public convenience and safety, and in their appropriate relation to the proposed use of the area to be served.
(2) Minor streets. Minor streets should be so planned as to discourage their use by non-local traffic. Dead end streets are prohibited, but cul-de-sacs will be permitted where topography, or other conditions, justify their use. Cul-de-sacs shall normally not be longer than 500 feet, including a terminal turn around which shall be provided at the closed end, with a right-of-way radius of not less than 70 feet.
(3) Future street system. Where the plat to be submitted includes only part of the tract owned, or intended, for development by the subdivider, a tentative plan of a proposed future street system for the unsubdivided portion shall be prepared, and submitted, by the subdivider.
(4) Arrangement of larger parcels. When a tract is subdivided into larger than normal building lots or parcels, lots or parcels shall be so arranged as to permit the logical location and openings of future streets and appropriate resubdivision, with provision for adequate utility connections for resubdivision.
(5) Intersection of streets. Under normal conditions, streets shall be laid out so as to intersect as nearly as possible at right angles, except where topography, or other conditions, justify variations. The minimum angle of intersection of streets shall be 80 degrees. Street intersection jogs with an offset of less than 125 feet shall be avoided.
(6) U.S. or state highways. Wherever the proposed subdivision contains, or is adjacent to, the right-of-way of a limited access U.S. or state highway, or thoroughfare, provisions may be made for a marginal access street approximately parallel, and adjacent, to the boundary of the right-of-way, or for a street at a distance suitable for the appropriate use of land between the street and right-of-way. The distance shall be determined with due consideration of the minimum distance required for approach connections to future grade separations, grade crossings, or for lot depths.
(7) Alleys. Alleys shall be provided in commercial and industrial districts, except that this requirement may be waived where other definite, and assured, provision is made for service access, such as off-street loading, unloading, and parking consistent with, and adequate for, the uses proposed. Except where justified by special conditions, such as the continuation of an existing alley in the same block, alleys will not be approved in residential districts. Alleys, where provided, shall not be less than 16 feet wide for residential alleys, and not less than 25 feet for commercial and industrial alleys. Dead end alleys shall not be permitted, except that this requirement may be waived where an adequate turn around is provided.
(8) Half street dedications. Dedication of half streets will not be approved, except where it is essential to the reasonable development of the subdivision, and in conformity with the other requirements of these regulations, where it is found that it will be practical to require the dedication of the other half when the adjoining property is subdivided, or where it becomes necessary to acquire the remaining half by condemnation so it may be improved in the public interest.
(9) Minimum right-of-way widths.
(a) For all public ways hereafter dedicated and accepted, the minimum right-of-way widths for streets and thoroughfares shall be as shown in the comprehensive plan, and where not shown therein, the minimum right-of-way width for streets, thoroughfares, alleys, or pedestrian ways included in any subdivision shall not be less than the minimum dimensions for each classification as follows:
Classification
|
Width
|
Classification
|
Width
|
Collector street | 75 feet |
Industrial commercial alley | 25 feet |
Marginal access street | 50 feet |
Minor street | 60 feet |
Pedestrian way | 10 feet |
Residential alley | 16 feet |
Thoroughfare | 80 feet |
(b) Where existing, or anticipated, traffic on thoroughfares warrants greater widths of the right-of-way, the measurements in the table above shall be required.
(10) Street grades.
(a) The grades in all streets, thoroughfares, collector streets, minor streets, and alleys in any subdivision shall not be greater than the maximum grades for each classification as follows:
Classification
|
Grade Percent
|
Alley | 8% |
Collector street | 5% |
Minor street | 8% |
Thoroughfare | 4% |
(b) In addition, there shall be a minimum grade on all streets and thoroughfares of not less than five-tenths of 1%.
(11) Street alignment.
(a) The horizontal and vertical alignment standards on all streets shall be as follows (there shall be a tangent between all reversed curves of a length in relation to the radii of the curves so as to provide for a smooth flow of traffic):
Classification
|
Horizontal Radii of Centerline
|
Collector street | 400 feet minimum |
Minor street | 150 feet minimum |
Thoroughfare | 500 feet minimum |
(b) All changes in street grades shall be connected by vertical parabolic curves of such length as follows:
Classification
|
Vertical Parabolic Curves
|
Collector street or minor street | 20 times the algebraic difference in the percent of grade of the two adjacent slopes |
Thoroughfare | 30 times the algebraic difference in the percent of grade of the two adjacent slopes |
(12) Dedication as public streets. All proposed streets shall be offered for dedication as public streets. No private streets shall be permitted, except as set forth in other provisions of the city code.
(C) Lots.
(1) Minimum lot area. The minimum lot area, width, and depth shall not be less than established by Chapter 156 of the city code, except that in districts where a minimum area width, or depth, is not established, the lot area, width, and depth shall be adequate to serve the purposes for which the lot is to be used.
(2) Corner lots. Corner lots for residential use shall have additional width to permit appropriate building setback from both streets, as defined in Chapter 156 of the city code.
(3) Side lines. Side lines of lots shall be approximately at right angles to street lines, or radial to curved street lines.
(4) Double frontage lots. Double frontage lots shall be avoided, except where lots back on a thoroughfare, or other arterial street, or where topographic, or other conditions, render subdividing otherwise unreasonable. The double frontage lots shall have an additional depth of at least 20 feet in order to allow space for screen planting along the back lot line.
(5) Minimum required frontage. Every lot must have at least the minimum required frontage on a public-dedicated street other than an alley.
(D) Easements.
(1) Length and width minimum. An easement for utilities, at least six feet wide, shall be provided along each side of a side line of lots, and along any other lot line as may be deemed necessary to form a continuous right-of-way, at least 12 feet in width. If necessary for the extension of main water or sewer lines, or similar utilities, easements of greater width may be required along lot lines, or across lots.
(2) Connection with other easements. Utility easements shall connect with easements established in adjoining properties. These easements, when approved, shall not thereafter be changed without the approval of the Council, by resolution, upon the recommendation of the Planning and Zoning Commission.
(3) Additional easements. Additional easements for pole guys should be provided at the outside of turns. Where possible, lot lines shall be arranged to bisect the exterior angle so that pole guys will fall along side lot lines.
(4) Watercourses, drainage ways, channels, or streams. Where a subdivision is traversed by a watercourse, drainage way, channel, or stream, a stormwater easement, drainage right-of-way, or park dedication, whichever the Planning and Zoning Commission may deem the most adequate conforming substantially with the lines of watercourses, shall be provided, together with further width or construction, or both, as will be adequate for the stormwater drainage of the area.
(E) Public sites and open spaces. In subdividing land or resubdividing an existing plat, due consideration shall be given by the subdivider to the dedication, or reservation, of suitable sites for schools, parks, playgrounds, conservation areas, or other public, or semi-public, recreational areas or open spaces. Areas so dedicated, or reserved, shall conform as nearly as possible to the comprehensive plan. All areas to be reserved for, or dedicated to, public use shall be indicated on the preliminary plat in order that it may be determined when, and in what manner, such areas will be dedicated to, or acquired by, the appropriate agency.
(Prior Code, § 12.05)