Chapter 17.19
SUBDIVISION STANDARDS AND DESIGN
Sections:
17.19.010 Conformance requirements—Generally.
17.19.040 Application for exception to road standards.
17.19.050 Streets—Dedicated right-of-way or easement width and improved width.
17.19.060 Streets—General standards.
17.19.080 Streets—Safety standards.
17.19.100 Streets—Gravel, minimum standards.
17.19.130 Blocks—Size and shape.
17.19.150 Existing substandard lots.
17.19.170 Reservation of potential public sites.
17.19.010 Conformance requirements—Generally.
The proposed subdivision shall conform to:
A. The provisions of AS 40.15 as amended from time to time and all other relevant laws and regulations of the state;
B. All applicable ordinances, statutes, and regulations;
C. Substantially to the comprehensive plan of the city;
D. The regulations of the State Department of Environmental Conservation relating to lot size and lot elevation if the subdivision is not served by a public sewer, and provision for such services has not been made;
E. The regulations of the State Department of Highways relating to safety of access and the preservation of the public interest and investment in streets and highways if the subdivision or any lot contained therein abuts on a state highway. (Ord. 90-03 § 1 (part), 1990.)
17.19.020 Dedications.
All streets, alleys, easements and other public areas shown on the plat not previously dedicated to public use shall be so dedicated. (Ord. 90-03 § 1 (part), 1990.)
17.19.030 Access.
A. Every lot shall have access directly from a dedicated right-of-way or easement.
B. Access from lots directly onto streets other than a state highway may be restricted by the planning commission to protect public safety. (Ord. 90-03 § 1 (part), 1990; Ord. 14-08 § 9, 2014.)
17.19.040 Application for exception to road standards.
An exception to road standards may be requested if the subdivision meets the limitation requirements of Section 17.07.090. (Ord. 90-03 § 1 (part), 1990.)
17.19.050 Streets—Dedicated right-of-way or easement width and improved width.
A. Arterial Road. One-hundred-foot public dedicated right-of-way and twenty-six-foot improved width;
B. Collector Street. Sixty-foot public dedicated right-of-way or easement and twenty-six-foot improved width;
C. Major Local Streets. Sixty-foot public dedicated right-of-way or easement and twenty-four-foot improved width;
D. Minor Local Streets. Fifty-foot public dedicated right-of-way or easement and twenty-foot improved width;
E. State highways shall be subject to appropriate state standards;
F. Private access streets shall have at least a fifty-foot easement with a twelve-foot improved driving surface accessing up to six lots; a fourteen-foot improved driving surface accessing up to ten lots; and a twenty-foot finished surface accessing more than ten lots. Use of private access standards requires maintenance of the right-of-way ten feet on either side of the finished surface. (Ord. 90-03 § 1 (part), 1990; Ord. 14-08 § 10, 2014.)
17.19.060 Streets—General standards.
A. In General. Streets shall be designed and located in relation to existing and planned streets; topographical conditions and natural terrain features such as streams and existing tree growth; public convenience and safety; and the proposed uses of the land to be served by such streets.
B. Arrangement. Major streets shall be properly integrated with the existing and proposed system of major streets and highways. Minor streets shall be laid out to conform as much as possible to topography to permit efficient drainage and sewer systems.
C. Street Names. New street names shall not be so similar to the names of existing streets so as to cause confusion, but streets that are continuations of others already in existence and named shall bear the name of existing streets.
D. Dead End Streets. Dead end streets longer than one hundred fifty feet shall be prohibited.
E. Half Streets. Half streets shall be prohibited.
F. Cul-de-Sacs. Cul-de-sacs in areas served by community or city sewer and water systems shall have a maximum length of six hundred feet with a minimum turn-around diameter of sixty feet. Cul-de-sacs in areas served by on-site sewer and water systems or only by city or community sewer systems shall have a maximum length of one thousand three hundred feet.
Measurement of cul-de-sacs shall be along the centerline of the roadway from the near side of the intersecting street to the farthest point of the cul-de-sac. (Ord. 90-03 § 1 (part), 1990.)
17.19.070 Streets—Drainage.
Roads shall be constructed to:
A. Prevent ponding of runoff waters in roadside ditches which would degrade the quality of the roadway;
B. To provide that runoff waters will be conveyed to natural or manmade drainage courses;
C. Provide outfalls which prevent siltation or erosion of riparian habitats, channels, and other private or public property. (Ord. 90-03 § 1 (part), 1990.)
17.19.080 Streets—Safety standards.
A. Curves. Where a deflection angle of more than ten degrees in the alignment of a street occurs, a curve of reasonable radius shall be introduced. On streets one hundred feet or more in right-of-way width, the centerline of radius of curvature shall not be less than three hundred feet; on other streets, the centerline radius of curvature shall not be less than two hundred feet.
B. Reversed Curves. Reversed curves (sharp “S” curves in opposite directions) shall have a straight section of street (intermediate tangent) at least one hundred feet in length unless the curve radii are three hundred feet or more.
C. Broken Curves. Two curves in the same direction separated by a short straight stretch of road shall be avoided. The road shall be designed into a single curve of appropriate radius or with a straight stretch of road (intermediate tangent) at least one hundred feet between curves.
D. Sight Distances. A minimum sight distance, with visibility measured along the centerline of the street, shall be provided for both horizontal and vertical curves as follows:
1. Minor and major local streets or private access streets, one hundred twenty-five feet;
2. Arterials and collectors, two hundred twenty-five feet.
E. Anything other than straight stretches of road and gradual curves shall be avoided on high, long fills whenever possible. (Ord. 90-03 § 1 (part), 1990; Ord. 14-08 § 11, 2014.)
17.19.090 Intersections.
A. Right Angle. Streets shall intersect as nearly as possible at right angles and no intersection shall be at an angle of less than sixty degrees.
B. Rounded. Property lines at street intersections shall be rounded with a radius of at least twenty feet.
C. Distance Between Intersections. Where streets enter from opposite sides of a major street, intersections of less than one hundred fifty feet separation from centerline to centerline shall be avoided.
D. Three way intersections rather than four way intersections shall be designed unless topography, existing street patterns or property boundary patterns make such requirement impractical.
E. Not more than two streets shall intersect at one point unless approval is granted by the planning commission.
F. Intersection Sight Distances.
1. Intersecting local roads shall have a minimum sight distance of two hundred feet measured from the intersecting road’s centerline.
2. Collector roads shall have a minimum sight distance of two hundred seventy-five feet measured from the intersecting road’s centerline.
3. Arterial roads shall have a minimum sight distance of four hundred fifteen feet measured from the intersecting road’s centerline.
G. Grades. Maximum grades within fifty feet of an intersection for local streets shall be five percent; maximum grades within one hundred feet of collector streets shall be three percent. (Ord. 90-03 § 1 (part), 1990.)
17.19.100 Streets—Gravel, minimum standards.
A. Gravel street beds shall have all tree stumps cut flush with the ground or removed. The subdivider, or his designee, shall notify the office of the city manager for a preliminary street inspection prior to the placement of gravel upon the prepared street surface.
B. In place excavation material or borrow material shall provide for road stability and shall be composed of earth, sand, gravel, rock, or a combination thereof and shall contain no muck, peat, frozen material, roots, sod, or other deleterious material and shall be compactible.
C. Gravel street beds shall have a gravel depth sufficient to preclude excessive settlement. Not less than eighteen inches of gravel, compacted to ninety-five percent compaction, shall be used on the full length and width of streets to be constructed. The ratio for road shoulder slope shall be a minimum of three feet horizontal to one foot vertical.
D. Construction of streets in substandard soils or wetlands may require the use of geotextile stabilization material or suitable base materials upon which compacted gravel shall be placed. If geotextile stabilization material is utilized over substandard soils or organics, then the depth of subbase must be a depth which provides for stable embankment.
E. Roadway embankments shall be constructed to limit erosion.
F. The backslope ratio for drainage ways along roads shall be two feet horizontal to one foot vertical unless right-of-way constraints restrict it. In this case, the ratio may be altered to one and one-half feet horizontal to one foot vertical.
G. Intersecting driveways or other gravel streets or unusual drainage conditions shall be culverted. Streets shall normally be culverted near the point of intersection to provide proper drainage. Minimum culvert size shall be eighteen inches. Topographic conditions may require larger culverting on the basis of the planning commission’s review or the preliminary inspection by the city inspector. Culverts and fill over culverts shall conform to applicable Alaska State Department of Transportation and Public Facilities Standard Specification for Highway Construction (blue book) and related drawings.
H. Gravel streets shall be constructed in such a manner to allow a two percent slope from centerline to shoulder or shall be constructed in such a manner that proper drainage is provided.
I. The minimum requirements of this chapter may be adjusted subject to actual field conditions. To be adjusted below minimum standards, plans prepared or stamped by a registered engineer licensed in the State of Alaska based on a soil investigation and a report consisting of test holes at a minimum of every five hundred feet must be submitted and approved by the city manager or his designee.
J. Grades. The grade of arterial and collector streets shall not exceed six percent and the grade of other streets shall not exceed ten percent unless a steeper grade is necessitated by exceptional topography and approved by the planning commission. The minimum grade of all streets shall be one-half of one percent.
K. The site shall be available for inspection at all phases of construction. (Ord. 90-03 § 1 (part), 1990.)
17.19.110 Alleys.
A. Commercial and Industrial. Alleys shall be provided in all commercial and industrial districts. The planning commission may waive this requirement where other definite and assured provision is made for service access such as off-street loading and parking consistent with and adequate for the uses proposed.
B. Residential. Alleys shall not be approved in residential areas unless necessary because of topography or other exceptional circumstances.
C. Width. The width of alleys shall be at least twenty feet.
D. Dead-End. Dead-end alleys are prohibited. (Ord. 90-03 § 1 (part), 1990.)
17.19.120 Utility easements.
A. The planning commission shall require the reservation of utility easements along street rights-of-way and along lot lines in subdivisions when utility providers demonstrate a need for them. The subdivider and utility provider shall work together to agree on the location and width of easements prior to the planning commission hearing.
B. Easements for single phase utility service and for minor utility distribution within the subdivision shall be centered on rear and/or side lot lines and shall be a minimum of twenty feet wide (ten feet on each side) with a forty-foot guying easement when necessary.
C. Easements necessary for major utility distribution within the subdivision or for extending utilities to surrounding areas shall be a minimum of thirty feet in width and shall be provided within the street right-of-way whenever feasible.
D. All easements shall be sufficient to meet applicable city, state, and federal requirements.
E. Where utilities are deemed necessary, easements shall be reserved to provide for the extension of utilities to surrounding areas. The subdivider will be required to dedicate necessary easements but will not be required to build utilities to serve surrounding areas.
F. Where a subdivision is traversed by a watercourse, drainage way, channel or stream, there shall be a stormwater easement or drainage right-of-way conforming substantially with the lines of such watercourse, and such further width or construction, or both, as will be adequate for the purpose. (Ord. 90-03 § 1 (part), 1990; Ord. 14-08 § 12, 2014.)
17.19.130 Blocks—Size and shape.
The lengths, widths, and shape of blocks shall be such that are appropriate for the locality and type of development contemplated and that provide for adequate circulation patterns and traffic safety. (Ord. 90-03 § 1 (part), 1990.)
17.19.140 Lots.
A. Generally. The size, shape and orientation of lots shall be appropriate for the location of the subdivision and for the type of development contemplated.
B. Lot Dimensions.
1. Lot dimensions shall comply with the zoning ordinance.
2. Depth and width of properties reserved or laid out for commercial, industrial, and residential purposes shall be adequate to provide for the off-street service and parking facilities required by the type of use and development contemplated.
3. Residential lots abutting major streets and highways shall be platted with sufficient depth to permit adequate separation between the buildings and such traffic ways.
4. Lots should be designed with a suitable proportion between width and depth. Normal depth should not exceed two and one-half times the width, nor be less than one hundred feet.
C. Corner Lots. Corner lots shall be designed to permit setback on both streets as required by the zoning ordinance.
D. Lots at Right Angles. Lots at right angles to each other shall be avoided wherever possible, especially in residential areas.
E. Lot Lines. Side lot lines shall be substantially at right angles or radial to street lines.
F. Large Lots. Where lots are created of a size larger than normal for the area, the planning commission may require that the plat be so designed as to allow for the possible future resubdivision of such lots into sizes normal for the area.
G. Municipal Boundaries. Lots shall follow municipal boundary lines wherever practicable, rather than cross them.
H. Double Frontage. Lots abutting a street at both front and rear shall be avoided except where necessary to provide separation of residential development from traffic or to overcome specific disadvantages of topography and orientation.
I. Flag Lots.
1. The use of flag lots in standard and abbreviated subdivisions shall be prohibited unless the applicant requests a variance and the findings of fact required in Section 17.27.020 are met.
2. If a variance is approved, the flag lot shall conform to the following standards:
a. The “flagpole” portion of the lot shall not exceed in length 2.5 times the average lot width (excluding the flagpole) or twice the depth of the lot, whichever dimension is the lesser.
b. The flagpole shall be a minimum width of thirty feet and of a grade not exceeding fifteen percent.
c. The flagpole shall be parallel to the closest existing lot line.
d. The flagpole shall not interfere with future access to surrounding properties.
e. The flagpole shall provide access to only one lot.
f. The flagpole is not adjacent to an adjoining flag lot or parallel to a public or private road unless unique topographic conditions exist which would effectively prevent access from the existing road.
g. No redivision shall be allowed to alter the status of the flagpole driveway unless other access, meeting all of city, state, and federal requirements is first provided. (Ord. 90-03 § 1 (part), 1990.)
17.19.150 Existing substandard lots.
Conveyance Restricted—Petition for Determination. In the case of a lot record at the time of passage of land use regulations affecting that lot, which does not conform to the land use regulations of the city, and which adjoins along a side lot line property held in the same ownership, no such lot shall be conveyed nor shall a building permit be issued for a structure on such a lot except in conformity with the following:
A. The owner of such substandard lot may, at any time prior to the proposed conveyance of such lot or request for building permit, petition the city for a determination as to the status of such lot.
B. Such petition shall be referred to the planning commission for study to determine the practical possibility of a redivision of such ownership to provide lots which will be in conformity to the land use regulations of the city and shall act within sixty days to give consideration, among others, to the following factors:
1. The size, quality, and character of existing lots and building development in the immediate area with a view to maintaining compatibility and protecting existing values.
2. Where public sewer is not available, a lot size necessary to comply with DEC standards.
3. The economic and engineering practicability of any possible redivision. (Ord. 90-03 § 1 (part), 1990.)
17.19.160 Utilities.
Constructed to required state and federal standards. (Ord. 90-03 § 1 (part), 1990.)
17.19.170 Reservation of potential public sites.
A. Design Consideration. In the design of the plat, consideration shall be given to the adequate provision of and correlation with public sites or open areas which insure adequate open spaces, sites for public use, public safety, and which serve to most equitably apportion the cost of providing public facilities necessary to serve additional families brought into the community by the subdivision development.
B. Reservation May Be Required. Where it is determined by the planning commission that a portion of the plat is required for such public sites or open spaces, the subdivider may be required to reserve such area for a period not to exceed three years, after which the city shall either acquire the property or release the reservation.
C. Tracts or lots which may be returned to the subdivider shall be provided with legal and physical access, right-of-way easements for utilities, and other requirements for buildable lots required by this code in the event that lots or tracts are subsequently sold. (Ord. 90-03 § 1 (part), 1990.)