Chapter 16.16
DESIGN STANDARDS
Sections:
16.16.010 Conformance to standards generally.
16.16.030 Design—Lot dimensions.
16.16.050 Design—Lot frontage and access.
16.16.055 Design—Snow storage.
16.16.060 Design—Reserve strips.
16.16.070 Design—Hazardous areas.
16.16.080 Design—Phasing schedule.
16.16.090 Design—Block arrangement.
16.16.100 Streets—General design considerations.
16.16.110 Design—Street grades.
16.16.120 Design—Street alignment.
16.16.130 Design—Street intersections.
16.16.150 Design—Street names.
16.16.160 Design—Street addresses.
16.16.170 Design—Geometric and profiles.
16.16.180 Engineering and design criteria.
16.16.010 Conformance to standards generally.
A proposed subdivision design shall conform to the following standards:
A. All applicable provisions of this code and any other ordinances of the city;
B. The comprehensive development plan;
C. The official map;
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 service has not been made;
E. The regulations of the State Department of Transportation and Public Facilities relating to safety of access and the preservation of the public interest and investment if the subdivision or any lot contained therein abuts on a state highway;
F. The Valdez coastal management plan. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-20)
16.16.020 Design—Lot layout.
In areas served by municipal sewer and water the preferred lot layout is two tiers of lots on a cul-de-sac street with snow storage at the street end. Examples of the preferred development layout are available from the director. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-21)
16.16.030 Design—Lot dimensions.
A. Subject to the lot dimension and area requirements in the zoning regulations, all lots shall have the minimum dimensions required by this section.
B. The depth of a lot shall be at least one hundred feet.
C. The width of a corner lot shall be a minimum of seventy-five feet. Corner lots shall be designed to permit full setback on both streets as required by the applicable zoning district requirements.
D. The width of a lot shall be at least one-third the depth of the lot.
E. Double frontage and reversed frontage lots shall be avoided, except where necessary to provide separation of residential development from traffic arteries or to overcome specific disadvantages of topography and orientation.
F. Where lots are created of a size larger than the minimum for the area, the commission may require that the plat be so designed as to allow for the possible future re-subdivision of such lots into the minimum size required for the area.
G. Notwithstanding any other provision of this section, the width of the flag pole portion of a flag shaped lot shall be no less than:
1. Thirty feet when both public water and sewer systems are to serve such a residential lot;
2. Forty feet when both public water and sewer systems are to serve such a commercial or industrial lot;
3. Twenty feet when only a public water or a public sewer system are to serve such a lot;
4. Twenty feet when the lot is located in a rural area and will not be served by either public water or public sewer systems. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-22)
16.16.040 Design—Lot lines.
To the extent feasible, side lot lines shall be perpendicular to straight streets and radial to curved streets. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-23)
16.16.050 Design—Lot frontage and access.
A. All lots shall have frontage on a publicly dedicated street or navigable water.
B. The front lot line of a residential lot shall not abut a major street and shall not face a lot zoned or used for industrial purposes, except that an exemption may be granted in rural areas where access is limited to such streets.
C. The total width of driveway entrances to a lot from a street shall not exceed two-fifths of the frontage of that lot on that street, unless the subdivider provides for snow storage in a manner approved by the platting authority.
D. The frontage of a lot on a cul-de-sac bulb shall be at least thirty feet. This subsection does not apply to flag lots.
E. All street rights-of-way shall include an open area, which may contain sidewalks, for snow storage. The open area shall extend ten feet outward from the back of the curb.
F. No driveway shall be located closer than fifty feet from the corner of an intersection.
G. Depth and width of properties reserved or laid out for commercial and industrial purposes shall be adequate to provide for the off-street service and parking facilities required by the type of use and development contemplated. (Ord. 05-11 § 4; Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-24)
16.16.055 Design—Snow storage.
A. Snow storage areas shall be dedicated to the city. The size of the snow storage shall be equal to one square foot for every square foot of constructed street area, including sidewalks, with a minimum street width of thirty feet. The snow storage lots shall not be located more than one thousand feet apart. The location and layout of snow storage lots shall be designated after consultation with the public works director and approved by the commission.
B. The snow storage lots shall be cleared and graded to ensure that drainage from the snow storage lots does not adversely impact adjacent property. The final drainage plan for the snow storage lots shall be approved by the city engineer. (Ord. 96-27 § 1 (part))
16.16.060 Design—Reserve strips.
Privately owned strips may not be reserved to control access to public rights-of-way. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-25)
16.16.070 Design—Hazardous areas.
The design of a subdivision containing or abutting hazardous areas shall conform to this section, in addition to the remainder of this title.
A. The subdivider shall demonstrate to the satisfaction of the platting authority, that the design is specifically adapted to the proposed development and that the design takes into account other development in the vicinity and does not increase hazards to other areas.
B. The commission may require the dedication of easements to construct and maintain cut and fill slopes and other control structures including but not limited to dikes or riprap.
C. Subdivision design shall take into consideration known areas susceptible to geophysical hazards including but not limited to landslide, mud and earth flow, soil creep, soil liquefaction, avalanche chutes, run-outs, or wind blast. Subdivisions which include areas within the tidal wave run up zone as indicated on official city maps and adopted studies shall have these areas identified and labeled “not for human occupation, tidal wave run up area.”
D. The commission shall require the dedication of stream maintenance and protection easements where a river, stream, creek, important surface watercourse, or drainage course traverses or is adjacent to the subdivision. The easement shall conform substantially to the line of the stream. Subject to subsection B of this section, the width of the easement shall be that which the platting authority or the director, as the authority applies, finds necessary to provide access to widen, deepen, slope, improve and maintain the stream, and to protect the stream and adjacent property from soil erosion, flooding, water pollution, and destruction of fish and wildlife habitat.
E. All stream maintenance and protection easements shall be at least twenty-five feet wide on either side of the stream, measured landward from the ordinary high water mark.
F. Within a stream maintenance and protection easement, all structures shall be readily movable or temporary. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-26)
16.16.080 Design—Phasing schedule.
The commission may require that a subdivision conform to a phasing schedule based upon the scheduled availability of infrastructure to serve the subdivision. The commission, upon a showing of good cause by the subdivider, may authorize the subdivider to proceed with the installation of improvements required under this title on a portion or part of the subdivision. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-27)
16.16.090 Design—Block arrangement.
Blocks shall consist of two tiers of lots, except where lots back onto a major street, natural feature or subdivision boundary. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-28)
16.16.100 Streets—General design considerations.
A. The streets in a subdivision shall be designed and located in relation to existing and planned streets, to topographical conditions and natural terrain features such as streams and existing tree growth, to public convenience and safety, and in their appropriate relation to the proposed uses of the land to be served by such streets. All subdivisions shall have legal and physical access.
1. Major Streets. Major streets shall be properly integrated with the existing and proposed system of major streets and highways.
2. Collector Streets. Collector streets shall be properly related to special traffic generating from facilities such as schools, churches and shopping areas to population densities, and to major streets into which they feed.
3. Minor Streets. Minor streets shall be laid out to conform as much as possible to topography, to discourage use by through traffic, to permit efficient snow removal, drainage and sewer systems and to require the minimum amount of street necessary to provide convenient, safe access to property.
B. Where a subdivision borders on or contains an existing or proposed major street, the commission may require that adjacent collector or minor streets be provided.
C. The rights-of-way of all streets shall be of the width specified on the official map or comprehensive plan or, if no width is specified there, they shall be not less than the width specified below, unless necessitated by unusual topographic, physical or design features.
|
Street |
Right-of-Way (feet) |
|---|---|
|
Major streets |
100 |
|
Collector streets |
80 |
|
Minor streets |
50 |
(Ord. 05-11 §§ 5, 6; Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-29)
16.16.110 Design—Street grades.
A. Streets shall be arranged properly in relation to topography to provide usable lots, safe streets, reasonable gradients, and minimum damage to terrain and existing vegetation. The minimum grade of all streets shall be no less than one-half percent and such minimum shall not be permitted for distances greater than six hundred feet.
B. Cul-de-sac turnaround grades shall not exceed five percent.
C. Major and collector street grades shall not exceed six percent unless necessitated by exceptional topography and approved by the commission. Minor street grades proving access to steep lots shall not exceed eight percent. Any street grade exceeding six percent shall be on a straight alignment no more than one hundred feet long; provided, that the commission may allow the grade to be longer where required by topographic conditions and consistent with sound design principles. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-30)
16.16.120 Design—Street alignment.
A. Collector streets shall be aligned to continue existing streets from adjoining areas into the proposed subdivision. Local streets shall be aligned to discourage their use by through traffic.
B. Stub streets with temporary turnaround areas shall be extended to the boundaries of the proposed subdivision where appropriate to provide future street connections to adjacent unsubdivided areas.
C. Grade or median separations of street lanes may be permitted to preserve natural features, provide space for landscaping, or facilitate access in subdivisions containing steep lots.
D. The minimizing of potential wind damage and snow removal shall be considered in aligning streets. (Ord. 05-11 § 7; Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-31)
16.16.130 Design—Street intersections.
Streets shall intersect at or as near as feasible to a ninety-degree angle and in no event less than a seventy-five-degree angle. The distance between intersection centerlines shall be at least one hundred fifty feet. Corner roundings at intersections shall have a minimum radius of twenty feet. A minimum sight distance shall conform with AASHTO policy for geometric design or highway and streets, with clear visibility, measured along the centerline of the street, shall be provided for at least three hundred feet on major streets, two hundred feet for collector streets and one hundred feet on minor streets. Pedestrian crosswalks not less than fifteen feet wide may be required by the commission where deemed desirable to provide convenient pedestrian circulation or access to schools, playgrounds, shopping areas, transportation and other community facilities. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-32)
16.16.140 Design—Culs-de-sac.
Where topography and traffic circulation permit, the length of a cul-de-sac shall not exceed nine hundred feet. The length shall be measured from centerline of intersecting through streets to the radius point of cul-de-sac bulb or a line running from the radius point perpendicular to the street centerline. A cul-de-sac shall terminate with a turnaround having a minimum radius of the right-of-way of fifty feet, and forty-one and one-half feet back of curb for constructed streets. In rural residential subdivisions, the minimum radius shall be eighty feet. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-33)
16.16.150 Design—Street names.
New street names shall not duplicate the names of existing streets, but streets that are continuations of others already in existence and named shall bear the name of the existing streets. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-34)
16.16.160 Design—Street addresses.
A. The director shall assign all official street address numbers. A permanent address shall be assigned only for property that is subject to a plat filed depicting the dedicated right-of-way serving the property.
B. The director may establish uniform street address numbering procedures. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-35)
16.16.170 Design—Geometric and profiles.
In addition to the requirements below, the provisions of Chapter 12.04 and Section 16.16.180 apply. Detailed requirements for current construction materials and methods are available from the director.
A. Horizontal Curves. Changes in horizontal alignment of roads shall be made through the use of horizontal circular curves. The radii of such curves shall not be less than:
1. Major streets, eight hundred feet;
2. Collector street, six hundred feet;
3. Minor street, one hundred fifty feet.
B. Compound curves and broken-back curves should not be used. Reverse curves should have an intermediate tangent of one hundred feet or more unless the curve radii are three hundred feet or more.
C. Cross Slopes. The minimum road cross slope shall not be less than two percent.
D. Superelevations shall be installed in accordance with the AASHTO policy on geometric design of highways and streets. The maximum superelevation allowed is six percent. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 24-36)
16.16.180 Engineering and design criteria.
A. Dedicated streets in any residential subdivision within any service area of the city shall receive street maintenance and snow removal only if all of the streets located within such subdivision are dedicated to public use and meet the engineering and design criteria set by the planning and zoning commission. In determining the engineering and design criteria to be applied to such subdivision the planning and zoning commission shall consider the following factors:
1. The anticipated population density within the subdivision;
2. The anticipated level of vehicular traffic upon the subdivision streets;
3. The anticipated level of pedestrian traffic upon the subdivision streets;
4. The cost of constructing such streets to higher engineering and design criteria as compared to the benefits derived from such higher criteria.
The acceptable criteria are set forth in Exhibit A, and the planning and zoning commission shall specify Type I, II or III, or a combination thereof. The planning and zoning commission may impose additional conditions or requirements as it deems to be in the public interest. It may set different engineering and design criteria for different subdivisions and for different streets within a subdivision and is not limited by any of the requirements of this title.
B. A subdivision in which the streets do not meet the criteria or requirements set forth by the planning and zoning commission will not be accepted.
C. The criteria and requirements referred to in subsection A of this section shall be determined by the planning and zoning commission prior to final approval of a subdivision plat and shall be noted on the face of the plat.
D. The city or any property owner within the city may appeal to the city council from the criteria determined by the planning and zoning commission by giving written notice of the appeal, stating the reasons therefor, to the city clerk within thirty days from the determination.
E. The planning and zoning commission shall determine criteria and requirements for subdivisions presently in existence, but which have streets not in conformance with street design requirements presently existing under this title. The commission shall require streets of Type I, II or III, or a combination thereof, together with such additional requirements as the commission may deem to be in the public interest. For any particular street in a subdivision which the commission determines may be a Type III street, and which presently is constructed in accord with Type III standards except that its width is between twenty-four and thirty feet, the commission, in its discretion, may approve a road width of not less than twenty-four feet. These criteria and requirements shall be set within ninety days after the effective date of the ordinance from which this section is derived, after twenty days’ notice to property owners of record in the subject subdivision. No determination of criteria and requirements need be made for existing subdivisions in which all streets meet Type I or II standards. (Ord. 96-27 § 1 (part): Ord. 93-03 § 1 (part): prior code § 23-5)