(A) Blocks.
(1) Block length. In general, intersecting streets, determining block lengths, shall be provided at the intervals as to serve cross-traffic adequately and to meet existing streets. Where no existing plats control, the block 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 the 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 2 tiers of lots of appropriate depth. Blocks intended for business or industrial use shall be of the 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) Arrangement of thoroughfares and collector streets. The arrangement of thoroughfares and collector streets shall conform as nearly as possible to the City 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 or adjacent subdivisions, or provide for future connections to adjoining unsubdivided tracts. The arrangement of thoroughfares and collector streets shall be considered in their relation to the reasonable circulation of traffic, to topographic conditions, to run-off of storm water, 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. Permanent cul-de-sacs shall normally not be longer than 500 feet, including a terminal turn-around that shall be provided at the closed end, with a right-of-way radius of not less than 50 feet.
(3) Unsubdivided plat portion. 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) Larger than normal building lots. When a tract is subdivided into larger than normal building lots or parcels, the 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 the resubdivision.
(5) Angle of intersection. Under normal conditions, streets shall be laid out so as to intersect as nearly as possible to 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) Marginal street access. Wherever the proposed subdivision contains or is adjacent to the right-of-way of a limited access U.S. or state highway or thoroughfare, provision 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 appropriated 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. 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 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 20 feet wide for residential alleys and not less than 25 feet wide 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 streets. 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 improved in the public interest.
(9) 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 in the Plan, 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:
1. Thoroughfare - 100 feet;
2. Collector street - 70 feet;
3. Minor street - 70 feet;
4. Marginal access street - 50 feet;
5. Residential alley - 20 feet;
6. Industrial-commercial alley - 25 feet; and
7. Pedestrian way - 10 feet.
(b) Where existing or anticipated traffic on thoroughfares warrants greater widths of rightway, these 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:
1. Thoroughfares - 4%;
2. Collector street - 5%;
3. Minor street - 8%; and
4. Alley - 8%.
(b) In addition, there shall be a maximum grade on all streets and thoroughfares of not less, than 5/10 of 1%.
(11) Street alignment. The horizontal and vertical alignment standards on all streets shall be as follows:
(a) Horizontal - radii of center line (There shall be a tangent between all reversed curves of a length not less than 50 feet.):
1. Thoroughfare - 500 feet minimum;
2. Collector street - 400 feet minimum; and
3. Minor street - 150 feet minimum.
(b) Vertical - all changes in street grades shall be connected by vertical parabolic curves the lengths as follows:
1. Thoroughfares 30 times the algebraic difference in the percent of grade of the 2 adjacent slopes; and
2. Collector street 20 times the algebraic or minor street difference in the percent of grade of the 2 adjacent slopes.
(12) 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 city code provisions.
(C) Lots.
(1) Frontage on public dedicated street. The minimum lot area, width, and depth shall not be less than that established by Chapter 152, 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 152.
(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) Frontage on public dedicated street. Every lot must have at least the minimum required frontage on a public dedicated street other than an alley.
(D) Easements.
(1) Easements for utilities. An easement for utilities, at least 10 feet wide, shall be provided along each side of a rear lot line of lots and along any other lot line as may be deemed necessary to form a continuous right-of-way, at least 20 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) Easement connections. 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 motion 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 alongside lot lines.
(4) Subdivision traversed by a water course. Where a subdivision is traversed by a water course, drainage way, channel, or stream, a storm water 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 the water courses shall be provided, together with the further width or construction, or both, as will be adequate for the storm water drainage of the area. The Community Development Director shall determine the width of the easements.
(E) Public sites and open spaces.
(1) 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.
(2) Areas so dedicated or served shall conform as nearly as possible to the City 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 the area will be dedicated to or acquired by the appropriate agency.
(Ord. 239, § 1509, passed 1-22-2000; Am. Ord. 6, Second Series, passed 7-23-2007) Penalty, see § 10.99