Municipality of Anchorage, AK Chapter 21.08 SUBDIVISION STANDARDS

§ 21.08.010 Purpose.

A. General. These standards are enacted generally to promote the goals of the comprehensive plan as to the health, safety, convenience, quality of life, and welfare of the present and future inhabitants of the municipality; to secure adequate utilities and public facilities, provide for consideration of school and open space needs, and protect sensitive natural areas such as critical habitat, high-value wetlands, and riparian corridors; to enhance or preserve other significant natural features; to ensure the functional and efficient layout and appropriate use of land so as to achieve property lots of reasonable utility and minimize public costs to construct and maintain infrastructure; and to facilitate orderly growth and harmonious development of the municipality.

B. Specific. Planning, layout, and design of a subdivision are of the utmost concern. The subdivision should provide safe, efficient, and convenient movement to points of destination or collection. Modes of travel to achieve this objective should not conflict with each other or abutting land uses. Lots and blocks should provide appropriate settings for the buildings that are to be constructed, make use of natural contours, and protect residents from adverse noise and vehicular traffic. Important natural features of the area should be preserved. Schools, parks, and other community facilities should be planned as an integral part of the area. New development should reflect and maintain the character of the neighborhood through layout of roads and lots, consideration of connectivity with minimal cut-through traffic, pedestrian access to neighborhood destinations, and buffers or open space where appropriate to maintain privacy and views.

(AO 2012-124(S), 2-26-2013)

§ 21.08.020 Applicability.

A. Generally. This chapter shall be applicable to all subdivision of land within the municipality that results in the partitioning, dividing, combining, or altering of any lot, parcel, or tract of land, including subdivisions created by an exercise of the power of eminent domain by an agency of the state or municipality.

B. Approvals required.

1. General. Before a preliminary plat for a subdivision shall be granted, the owner or his or her authorized agent shall apply for and secure approval under the provisions of Section 21.03.200, Subdivisions.

2. Before certificate of zoning compliance. A certificate of zoning compliance shall not be issued, pursuant to Section 21.03.060, and a building or structure shall not be occupied, until and unless all dedications and improvements required by this chapter have been installed or agreements/guarantees made in a satisfactory manner and approved by the municipality.

C. Design Criteria Manual. Whenever the Design Criteria Manual is referenced in this chapter, the reference shall mean the version of the Design Criteria Manual in effect at the time of preliminary plat approval.

(AO 2012-124(S), 2-26-2013)

§ 21.08.030 Design standards.

A. Subdivision layout and design generally. No subdivision shall be approved unless it complies with all of the following standards:

1. Name of subdivision. The title under which the subdivision will be recorded shall not duplicate the name of any existing subdivision in the municipality.

2. Compliance with comprehensive plan. The design of subdivisions shall further the goals and policies of the comprehensive plans as set forth in this title.

3. Compliance with other provisions of this title. All subdivisions shall comply with all other applicable zoning, design, and development requirements set forth in this title.

B. Phasing schedule. The platting authority may require that a subdivision conform to a phasing schedule based upon the scheduled availability of infrastructure to serve the subdivision. Submittals for the initial phase of a subdivision shall indicate utility easements and transportation connections to adjacent and undeveloped land/areas that are not part of the initial phase yet are under the same ownership.

C. Maintenance of existing natural drainage. The general lot configuration and layout of proposed rights of way, open space tracts, and development setbacks shall be consistent with naturally occurring drainage features and historical drainage patterns within the subdivision and surrounding areas. The subdivider shall demonstrate to the department of public works that reasonable efforts have been made to avoid and/or mitigate the damming, diversion, and/or contamination of natural and historical drainageways or watercourses. The subdivision design shall ensure that neighboring parcels, adjacent rights of way, water bodies, wetlands, and existing storm drainage facilities are not adversely impacted by new or altered drainage resulting from the development.

D. Drainage design. All drainage facilities shall comply with the standards of Section 21.07.040, Drainage, Storm Water Treatment, Erosion Control, and Prohibited Discharges, as implemented by the Design Criteria Manual.

E. Legal and physical access. A subdivision shall have legal and physical access.

F. Streets. All streets shall comply with the standards of this chapter and Section 21.07.060, Transportation and Connectivity, the specifications of the Design Criteria Manual, and the following intent and standards:

1. Intent Streets shall be arranged in relation to topography to provide usable lots, safe streets, safe and convenient pedestrian walkways and crossings, reasonable gradients, and minimum damage to terrain and existing vegetation.

2. Street grades.

a. Street grades shall be as required by the Design Criteria Manual.

b. Applicable streets shall comply with the standards of section 21.08.030H, subdivisions on slopes.

3. ROW open area. All street rights-of-way shall include an open area, which may contain sidewalks, for temporary snow storage. The open area shall extend seven feet outward from the back of curb or pavement edge.

4. Street alignment.

a. Arterial and collector streets shall be aligned to continue those streets from adjoining areas into the proposed subdivision. Local streets shall be aligned to discourage their use by through traffic, except in the DT districts. This provision is not intended to encourage cul-de-sacs or dead-end streets. 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.

b. Grade or median separations of street lanes may be permitted to preserve natural features, provide space for landscaping, or facilitate access in subdivisions containing hillside lots.

5. Street intersections. Streets shall intersect at or as near as is feasible to a 90-degree angle and in no event at less than a 75-degree angle. The distance between intersection centerlines shall be at least 150 feet. Corner roundings at intersections shall conform to the standards of the municipal engineer.

6. Culs-de-Sac.

a. Where topography and traffic circulation permit, the length of a cul-de-sac right-of-way shall not exceed 900 feet in the R-6, R-8, R-9, R-10, and TA zoning districts, and 600 feet in all other zoning districts. The platting authority may approve longer cul-de-sacs when necessary to accommodate natural features.

b. The length shall be measured from the centerline of intersecting through streets to the radius point of the cul-de-sac bulb.

c. A cul-de-sac right-of-way shall terminate with a turnaround having a minimum radius of 50 feet and a minimum return radius of 50 feet. Commercial/industrial cul-de-sacs shall have a minimum radius of 65 feet. The platting authority may permit a cul-de-sac street to terminate with a T-shaped or Y-shaped turnaround, or other turnaround approved by the traffic engineer, when such a design is required by extreme environmental or topographical conditions or unusually or irregularly shaped boundaries.

7. Alleys. Dead-end alleys shall be prohibited.

8. Street names and addresses.

a. The subdivider shall provide names for all new streets in the subdivision, which names shall neither duplicate, nor be subject to confusion with, the spelling or the pronunciation of any existing street name in the municipality. The subdivider's selection of street names shall be subject to review by the director, who may reject any proposed street name that does not conform to this section or to any regulation promulgated pursuant to this section. The municipality shall name all streets that are peripheral to the subdivision and all extensions of existing streets into the subdivision.

b. The director may promulgate regulations establishing a uniform street designation terminology. All street names shall conform to the terminology so established.

c. Street names may be modified using the procedure set forth in section 21.03.185.

9. Street addresses.

a. The director shall assign all official street address numbers within the municipality. A permanent address shall be assigned to occupiable buildings, and to other locations at the discretion of the director. Buildings with more than one unit shall be assigned sub-addresses. Addresses shall be displayed as required in section 21.07.010C.

b. The director may promulgate regulations establishing uniform street address numbering technology and procedures. All street addresses shall conform to the numbering technology and procedures adopted by regulation, unless unusual or exceptional circumstances warrant utilization of alternate technology or procedures.

G. Block arrangement.

1. Blocks shall have sufficient width to provide for two tiers of lots of depth meeting the minimum requirements of this title, except where lots back onto a collector or greater street, natural feature, or subdivision boundary, or where lots face an approved loop road or cul-de-sac.

2. Residential blocks in class A improvement areas (as defined in section 21.08.050B) shall not be less than 300 feet nor more than 500 feet long. Residential blocks in class B improvement areas shall not be less than 300 feet nor more than 1,320 feet long. The platting authority may approve a longer block length when necessary to accommodate natural features such as steep slopes, or when the longer block is divided by an improved pedestrian easement that provides connectivity and traffic circulation is not impaired.

H. Subdivisions on slopes.

1. Applicability. This section applies to parcels to be subdivided that are five acres or more, and

a. Have an average slope of 20 percent or greater over the entire property; or

b. 30 percent of the entire property to be subdivided has slopes of 30 percent or greater.

2. Additional submittal requirements. In addition to the submittal requirements in Section 21.03.200, applications for applicable subdivisions shall include a geotechnical engineering report that contains the following information:

a. Geology of the site: description of the geology of the site, including the nature, strength, and stability of the soils, the character and depth of any imported material; depth to groundwater and to bedrock; any avalanche and mass wasting areas; fractures; and any other significant geologic features.

b. Slope stability analysis: conclusions concerning the effects of material addition and/or removal, grading, presence of water (both on and offsite), seismic activity, and erosion, on slope stability.

c. Conclusions regarding the adequacy of the site for development, and specific recommendations for procedures for cut and fill slope stability, seepage and drainage control, grading, and all other applicable design criteria to mitigate geologic hazards, slope failure, and soil erosion, and to minimize disturbance to natural ecological and drainage functions.

d. A summary of field exploration methods and tests on which the report is based, such as probings, core drilling, or test pits.

3. Design standards.

a. For phases of subdivisions where all the lots created are 40,000 square feet or greater in area, the subdivider shall show for each lot that has an average slope of 20 percent or greater, to the satisfaction of the platting authority, a site disturbance envelope that:

i. Meets the requirements of section 21.07.020C.3.c; and

ii. If applicable, accommodates on-site systems meeting the requirements of AMC Title 15.

b. Phases of subdivisions that include any lots less than 40,000 square feet in area shall use the conservation subdivision process at Section 21.08.070.

4. ROW reductions. The platting authority may, with the recommendation of the municipal engineer, approve reductions in right-of-way standards in order to keep grading and cut and fill slopes to a minimum.

5. Downslope lots. Road/driveway access to all lots less than 5 acres with an average slope of 30 percent or greater shall be from the upslope side of the lot.

6. Sidewalks/Pathways. Requirements for sidewalks or pathways along local streets may be reduced or eliminated by the platting authority. In deciding the extent of pedestrian facilities to be required, the platting authority shall consider negative impacts to the terrain, the cost of improvements in relation to the anticipated use, the needs of pedestrians, and the identification of existing alternate locations for pedestrian facilities.

7. Grading. For phases of subdivisions where all the lots created are 40,000 square feet or greater in area, grading shall be limited to the road right-of-way to the maximum extent feasible. Mass grading of the entire subdivision is prohibited, except that previously disturbed areas, such as former gravel pits, may be graded. Lots shall be individually graded, within their site disturbance envelope, at the time of building construction, pursuant to section 21.07.020C. For the purposes of this subsection only, "previously disturbed" means alteration of the natural landform. It does not mean simply the removal of vegetation.

8. Vehicular routes. The intent of this subsection is to minimize disturbance to the natural landscape in the alpine areas of the municipality to the maximum extent feasible. This can be accomplished by a number of design techniques such as following the natural contour lines both horizontally and vertically, attaching required pedestrian paths to the edge of pavement, adjusting cut and fill slopes, or use of retaining structures.

a. Streets, roads, private access roads, and other vehicular routes shall be designed in accordance with the Design Criteria Manual and this subsection.

b. Land disturbance, including vegetation clearing and grubbing, grading, etc., shall be curtailed to the smallest area/extent feasible.

i. Initial land disturbance shall be limited to the proposed travel-way (lanes and shoulders) to accommodate land survey, geotechnical investigation of the in situ materials, and "rough" construction.

ii. The ultimate extent of land disturbance is dependent upon the nature of the subsurface materials. The extent of disturbance shall be the minimum necessary and is limited to within 25 feet of the right-of-way, including utility easements. Disturbance outside of the right-of-way and utility easements shall be re-vegetated using similar native trees and shrubs that were removed for the purpose of constructing the road improvements.

iii. The subdivision agreement shall be used to implement this subsection H.8.

c. Disturbed area abutting the right-of-way on both sides shall be contained within a slope reservation easement, for the purpose of providing and maintaining the lateral support of the constructed street. The slope reservation easement shall be in the form of a general dedication note on the plat.

d. Cut and fill slopes and all disturbed areas shall be stabilized and reinforced using appropriate engineering means. Vertical or near vertical constructed slopes or bedrock slopes shall be no taller than 12 feet. Vegetation employed as a means of stabilization outside of the right-of-way and utility easements shall replicate original native landscape conditions.

e. The platting authority may require common driveways to be shared by two or more lots, with the concurrence of the traffic engineer and the fire department, to avoid excessive and unnecessary disturbance to slopes by multiple and individual lot driveway cuts, and/or to avoid and/or reduce impacts to other natural features, such as wetlands, creeks, etc.

I. Seismically-induced ground failure hazard.

1. A geotechnical investigation shall be performed to evaluate the potential for seismic-induced ground failures across that portion of the subdivision within seismic zones 4 and 5 of the municipality's seismically-induced ground failure maps. The requirement for a geotechnical investigation shall apply to all zoning districts, unless otherwise waived by the platting authority.

2. A report of the findings and recommendations of the geotechnical investigation shall be prepared by a civil engineer licensed in the state of Alaska and submitted to the platting authority. The report shall include a discussion of the suitability of the proposed development and recommendations for any needed mitigation.

3. The scope of the geotechnical investigation shall include subsurface explorations (test borings), laboratory testing, and engineering analysis to evaluate the potential for, and potential magnitude of liquefaction, settlement, and lateral spreading, following methods conforming with the state-of-practice; and stability of existing slopes, natural or man-made, following methods defined in AMC Chapter 23.15, Section 1802.2.6D. These evaluations shall be based on probabilistic ground motion parameters corresponding to 475-year or greater return period.

4. The platting authority may reject a proposed subdivision in its entirety if the geotechnical investigation does not demonstrate that the area can be developed in accordance with this title and AMC Title 23.

5. The geotechnical investigation submitted with the plat application may supplement the requirements for geotechnical investigations included in AMC Title 23.

J. Avalanche zones. No lot shall be created, unless it is restricted to non-structural uses, that is completely in the "high hazard area", as identified on municipal avalanche maps based on the 1982 Anchorage Snow Avalanche Zoning Analysis or on amendments to those maps reviewed and approved by the geotechnical advisory commission.

K. Lot dimensions. Subject to the lot dimensions and area requirements of Chapter 21.06, all lots shall have the minimum dimensions required by this section.

1. The depth of a lot shall be at least 80 feet.

2. The width of a lot, except for a townhouse lot and a narrow lot or unit lot subdivision lot, shall be at least one-third the depth of the lot.

3. If a lot is to be served by an on-site wastewater disposal system, the lot shall have the minimum area required for such a lot under AMC Chapter 15.65.

4. Notwithstanding any other provision of this section, the width of the flagpole portion of a flag-shaped lot shall be no less than:

a. Thirty feet when both public water and sewer systems are to serve such a residential lot.

b. Forty feet when both public water and sewer systems are to serve such a commercial or industrial lot.

c. Twenty-four feet when only a public water or a public sewer system is to serve such a lot.

d. Twenty-four feet when the lot is located in the R-6, R-8, R-9, R-10 or TA districts and will not be served by either the public water or the public sewer system.

5. The length of the flag pole portion of the lot shall not exceed 300 feet in the R-6, R-8, R-9, R-10 or TA districts or 120 feet in all other districts, and all other measurements shall be consistent with other sections of this title.

6. To the extent possible, side lot lines shall follow natural terrain and create building sites that integrate into the natural terrain and minimize the need for fill and grading.

7. Lots tracted out for open space, well protection areas, or for undevelopable areas such as wetlands, are exempt from these dimensional requirements and the dimensional standards of chapter 21.06.

L. Lot frontage and access.

1. Except when platted under section 21.03.200E, commercial tract plats, or except for lots tracted out for open space, well protection areas, or for undevelopable areas such as wetlands, all lots shall have frontage on a street.

2. Unless approved by the director, access to a residential use on a residential lot shall not be from a collector or greater street as designated on the Official Streets and Highways Plan.

3. Subdivisions shall be designed to minimize lots with access to residential major streets carrying more than 1,000 average daily trips.

4. The frontage of a lot on a cul-de-sac bulb shall be at least 30 feet, except that the frontage on a cul-de-sac bulb of a lot with a side setback abated under section 21.06.030C.3, Construction on Adjoining Lots, shall be at least 18 feet. This subsection does not apply to flag lots.

5. In class A improvement areas, there shall be no more than one flag lot facing onto each cul-de-sac bulb.

M. Landscaping. The platting authority shall consider and require, where appropriate, landscaping and screening under Section 21.07.080, Landscaping, Screening, and Fences to separate property from incompatible uses or structures, including but not limited to streets designated for collector or greater capacity on the Official Streets and Highways Plan, commercial, or industrial uses. The area containing the landscaping shall be shown as an easement or open space area on the plat. The landscaping shall be installed before final plat approval, or its installation shall be guaranteed under Section 21.08.060, Subdivision Agreements, or by other performance guarantees acceptable to the platting authority. The landscaping shall be maintained by the property owner or designee.

N. Reserve strips. Privately owned strips may not be reserved to control access to public rights-of-way.

O. Electrical and telecommunication utilities. The width and alignment of transmission easements within subdivisions shall conform to the utility corridor plan. The platting authority shall preclude structures or uses of land within or beneath areas of electrical or telecommunications ground or aerial easements that are incompatible with electrical distribution or transmission facilities.

P. General subdivision standards are minimum standards.

1. The design standards in this chapter are minimum standards. The platting authority may impose more restrictive standards when it finds they are necessary to conform the design of a proposed subdivision to the approval criteria for subdivisions or to meet other requirements set forth in this title.

2. When the platting authority finds that it is not feasible to conform the design of a proposed subdivision to meet the approval criteria for subdivisions or other requirements set forth in this title, the platting authority may reject a proposed subdivision in its entirety.

(AO 2012-124(S), 2-26-2013; AO 2013-117, 12-3-2013; AO No. 2015-131, § 7, 1-12-2015; AO No. 2020-38, § 9, 5-28-2020; AO No. 2023-77, § 15, 7-25-2023)

§ 21.08.040 Dedication.

A. Streets.

1. All street rights-of-way shall be dedicated to the public, unless a variance for private streets is approved by the platting board. Applicants for a variance for private streets shall demonstrate the following:

a. Why a private street is appropriate and preferable to a publicly dedicated street;

b. That a private party is willing and able to maintain a private street to public standards; and

c. That a private street presents no conflict or obstruction to the orderly expansion of the public street system.

2. Street right-of-way widths shall conform to the Official Streets and Highways Plan (OS&HP). These standards are considered to be minimum standards and may be increased in a particular instance, where necessary, to make a proposed street conform to sound traffic engineering standards and principles. When steep slopes or other terrain features dictate, slope easements that exceed normal right-of-way requirements will also be required. Notwithstanding the above, the maximum dedication width that may be required for an arterial or collector street is 70 feet if the entire width of the street is within the subdivision, or 35 feet if the street is on an exterior boundary of the subdivision.

3. The platting authority may approve the dedication of a half-street only when the other half of the street has been dedicated or when the platting authority reasonably anticipates that the other half of the street will be dedicated. When a subdivision borders a dedicated half street, the platting authority shall require the dedication of the other half of the street, unless it determines that the street would be unnecessary or undesirable.

B. Alleys. The platting authority may require the dedication of alley rights-of-way where it finds that alleys are necessary for service access, off-street loading, or parking. The minimum width of an alley right-of-way shall be 20 feet.

C. Walkways. The platting authority shall require the dedication of pedestrian walkways where it finds that pedestrian walkways are necessary to provide for convenient and safe pedestrian circulation, to protect pedestrians from hazardous traffic, or as required in Section 21.07.060, Transportation and Connectivity. The minimum width of a walkway dedication shall be ten feet. The platting authority may require a wider dedication for reasons of topography, project use, or construction needs (if the walkway is to be paved).

D. Trails. The platting authority shall require the dedication of access for trails designated on adopted municipal plans, unless an alternative access point within the subdivision is clearly agreed to be preferable for dedication. For pedestrian access, a right-of-way dedication is the preferred method of providing access, but the platting authority may instead approve a public use easement dedication or an access tract where appropriate. If the platting authority approves an alternate location for trail access as a substitute for an existing easement or right-of-way, the existing unused easement or right-of-way shall be vacated, unless the property owner agrees otherwise. The platting authority may modify the alignment, width, and scope of trail access routes as necessary to integrate trail and subdivision design.

1. Access to community use areas and natural resource use areas.

a. The platting authority shall require the dedication of public pedestrian access for a trail designated on adopted municipal plans, for connectivity with a trail or access point to a large Community Use Area or Natural Resource Use Area (as defined in the Anchorage Bowl Park, Natural Resource, and Recreation Facility Plan or the Chugiak-Eagle River Comprehensive Plan). The platting authority may modify the alignment, width, and scope of trail access routes as necessary to integrate trail and subdivision designs, so long as the resulting trails are of comparable gradient, directness, and utility, and reflect the general locations and patterns of existing or planned public access routes. Acceptable pedestrian access shall be platted in accordance with relevant provisions of this title and be at least 20 feet wide, centered on an existing, recognized, new, or relocated trail.

b. The platting authority shall require the dedication of a vehicular right-of-way for public access to trails, parks, and other public lands as defined in subsection D.1 above that are identified in an adopted municipal plan. Acceptable vehicular right-of-way shall be a public street that is platted and dedicated in accordance with relevant provisions of this code.

E. Access to Chugach State Park.

1. During review and action on subdivisions at or near the boundary of the Chugach State Park, the platting authority shall require the dedication of public vehicular or pedestrian access to permit or preserve future access to the park unless, after consideration of the factors in subsection E.2 below, it determines that access at the subdivision is not appropriate and is not necessary to preserve future access to the park.

2. In determining whether or not such access shall be provided, the platting authority shall consider the Chugach State Park Access Plan, as well as the following criteria:

a. The size of the parcel to be subdivided;

b. The purpose of the subdivision;

c. The proximity of other existing and potential future access points, and their similarities or differences;

d. The proximity of any undeveloped secured site;

e. How dedication of an access point at the location will impact current private land use and current legal access;

f. Whether a comparable alternative access point could be made available through public land;

g. Recommendations from affected community councils and advisory boards entitled to notice under Section 21.03.020 or Section 21.10.030; and

h. Other factors to ensure an equitable balance between current private residential use and potential public access.

3. The access point locations identified in the Chugach State Park Access Plan may not be exact and may require some latitude in actual placement, considering feasibility and safety.

4. When pedestrian access is to be provided, new rights-of-way, easements, or access tracts should be a minimum of 20 feet wide; however, the platting authority may require a different width in order to provide safe trails wide enough to buffer neighboring residences. Dedicated right-of-way is preferred for pedestrian access, but public use easements or access tract dedication may be considered when justified.

5. Where vehicular access is to be provided to the park boundary that also provides access to new subdivision lots, the developer shall construct public improvements to front the subdivision lots along with a regulation turnaround. Where vehicular access to the park does not provide access to new subdivision lots, the developer shall not be required to construct the road. At such time that the state develops a new park access or trailhead at that location, the state will be responsible for constructing the vehicular access road.

6. Any party aggrieved by a decision of the platting authority may appeal the decision as indicated in Table 21.02-1.

F. Riparian protection and maintenance easements.

1. The platting authority shall require the dedication of riparian maintenance and protection easements where a stream, water body, or wetland traverses or is adjacent to the subdivision, in accordance with section 21.07.020B, stream, water body, and wetland protection.

2. The easement shall conform substantially to the line of the watercourse. The width of the easement shall be that which the platting authority 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. At a minimum, the easement shall be the same as the applicable setback required in the zoning district, as set forth in section 21.07.020B.4, buffer/setback requirements.

3. Section 21.07.020B, stream, water body, and wetland protection, sets forth additional restrictions on development and the use of land and structures within the easement and, in some districts, beyond the easement.

4. In cases where two or more easements coincide, the outer limits of the combined easement shall be measured from the outer edge of the outermost watercourse edge in either direction.

5. Credit towards other open space dedication or private open space set-aside requirements shall be given for the dedication of riparian protection and maintenance easements at a ratio of one-to-one.

G. Reserve tracts.

1. Sites designated.

a. The platting authority may require that an area designated as a park, playground, or open space in an officially adopted plan, as preservation wetland (as designated in the Anchorage Wetlands Management Plan), or as a school site pursuant to AMC Section 25.25.040 be designated as a reserve tract. The designation shall be supported by a report from the municipal agency or department requesting the reservation, containing a statement that the municipality intends to purchase the designated area within the period allowed under subsection F.2 below.

b. Special, natural, or manmade features of historical or community significance in a proposed subdivision which enhance or have unique value to the community may be set aside in a reserve tract for acquisition, or voluntarily dedicated to the public.

2. Time for acquisition.

a. Within 24 months of filing of a final plat, or the period of the school site designation provided by AMC Section 25.25.040B, whichever is earlier, the municipality or any other public or private agency may acquire any parcel designated as reserve tract on the plat, by purchase or as otherwise authorized by law, for the purpose for which the parcel was reserved under subsection F.1 above.

b. If a reserve tract is not acquired within such time, it shall be released from the reserve tract designation, unless the time for acquisition is extended by the reserve tract's owners, or by another provision of law.

c. In consideration of the reservation, the municipality shall pay the owners of the reserve tract an amount equal to the municipal real property taxes that accrue on the reserve tract, during the period of reservation.

H. Utility easements.

1. Public utilities shall be placed in dedicated rights-of-way unless the utility demonstrates that there is a specific need that warrants a location elsewhere. Pad-mounted facilities may be located in easements abutting rights-of-way. Electric and telecommunication utilities are encouraged to co-locate in trenches.

2. In situations where utilities may not be placed within rights-of-way, easements shall be provided for utilities, and shall be centered along or adjacent to lot lines to the greatest extent practicable.

3. Where a utility has demonstrated, pursuant to H.1 above, the need to locate outside the right-of-way, utility easements shall be sized as follows, but the platting authority may approve different standards when justified by demonstrable site conditions or utility needs. The platting authority shall size the easements as small as is feasible. After January 1, 2014, utility easements shall not be placed in tracts set aside to protect environmental features, such as wetlands or steep slopes.

a. Utility easements along rear lot or side lot lines where a primary voltage conductor is placed shall be at least ten feet wide, or a total of 20 feet wide along adjoining rear lots.

b. Utility easements along rear lot or side lot lines where a service voltage conductor is placed shall be five feet wide, or a total of ten feet wide along adjoining side lots.

c. Where a front yard easement is needed to accommodate a transmission utility, which is included in the utility corridor plan, the easement shall generally be ten feet wide.

d. The platting authority may require wider utility easements along the rear lot lines of hillside lots.

4. The platting authority shall require the dedication of utility easements when a utility company demonstrates a specific need for them or an easement is needed to accommodate the routing included in the Utility Corridor Plan.

(AO 2012-124(S), 2-26-2013; AO 2013-117, 12-3-2013; AO No. 2014-140(S), § 2, 3-24-2015)

§ 21.08.050 Improvements.

A. General requirements.

1. Compliance. The subdivider shall construct and install improvements in accordance with this section, the design standards in Section 21.08.030, and the Design Criteria Manual and Municipality of Anchorage Standard Specifications. In the event of a conflict between the design standards in this chapter, the Design Criteria Manual, and the Municipality of Anchorage Standard Specifications, the design standards in this chapter shall control.

2. Minimum standards. The improvement standards in this section are minimum standards. The platting authority may require additional or more extensive improvements when it finds they are necessary to conform a proposed subdivision to the standards of Section 21.08.030, or the subdivider may provide such additional or more extensive improvements.

3. Eligibility for warranty.

a. All improvements required under this section shall be constructed under a subdivision agreement as provided in Section 21.08.060, Subdivision Agreements. Lots in subdivisions shall not be eligible for conditional certificates of zoning compliance or certificates of zoning compliance until the subdivision improvements included in this section have been accepted for warranty by the municipality.

b. Projects may be placed on warranty in the autumn season without landscaping and/or permanent erosion control provided that:

i. All other improvements are accepted for warranty;

ii. Temporary erosion control is maintained throughout the winter;

iii. The warranty guarantee plus a performance guarantee for landscaping is provided;

iv. The subdivider/developer meets all of the criteria to go on warranty; and

v. A separate warranty period is provided for the landscaping/permanent erosion control.

4. Engineer registered in the State of Alaska.

a. The subdivider shall have construction plans for the improvements required under this section prepared by an engineer registered in the State of Alaska, in accordance with the requirements of the municipal engineer.

b. The engineer shall maintain in good standing professional liability insurance in the amount of $1,000,000.00 during the term of the agreement. Policies written on a "claims-made" basis shall have a two year tail of coverage from the completion of the subdivision agreement term. The required insurance policy shall provide for no less than 30 days advance notice to the municipality prior to cancellation.

B. Improvement areas defined. For the purpose of this section, the municipality is divided into two distinct improvement areas. The class A improvement area includes areas of more dense population and/or intensive development, and thus requires a more urbanized level of improvements. The class B improvement area includes areas that are less densely populated and/or intensely developed, and thus requires a less urbanized level of improvements. The zoning districts associated with each improvement area are listed in the table below. See sections 21.09.020B.2 and 21.10.080A for Girdwood and Chugiak-Eagle River improvement areas.

TABLE 21.08-1: IMPROVEMENT AREAS DEFINED
District Type	Class A	Class B
Residential	R-1 R-1A R-2A R-2D R-2M R-3 R-3A R-4 R-4A R-5	R-6 R-7 R-8 R-9 R-10
Commercial	B-1A B-1B B-3 RO MC
Downtown (DT)	B-2A B-2B B-2C
Industrial	I-1 I-2 MI
Other Districts	A	TA WS
AF District DR District PCD District PLI District PR District	The platting authority shall place a subdivision within any of these districts in the improvement area that it finds to be most compatible with the proposed use of the parcel and the zoning district classifications of the surrounding area.

C. Improvement requirements by improvement area.

1. The subdivider or developer shall construct and install the required improvements prescribed by this section for the improvement area where the subdivision is located in accordance with the table below:

TABLE 21.08-2: REQUIRED IMPROVEMENTS BY IMPROVEMENT AREA
R = Improvement Required
Improvement	Class A	Class B
Paved Interior Streets	R
Strip-Paved Access and Peripheral Streets	R	R
Strip-Paved Interior Streets		R
Curbs and Gutters	R
Sidewalks	R
Walkways	R	R
Street Lighting	R
Traffic Control Devices	R	R
Monuments	R	R
Drainage	R	R
Telephone & Electrical Facilities	R	R
Water Supply Facilities	R
Sanitary Sewer Facilities	R
Landscaping	R	R

2. Notwithstanding subsection C.1 above, improvements in the Hillside District Plan area shall comply with Table 4.5 of the Hillside District Plan (page 4-16). In the case of any conflict between the standards of this Section 21.08.050 and Table 4.5 of the Hillside District Plan, the plan shall govern.

D. Interior streets.

1. Residential interior streets.

a. Categories. There are two categories of residential interior streets:

i. Residential minor streets. Residential minor streets have the sole purpose of providing frontage for service and access to individual lots. These streets carry only traffic having either an origin or a destination on the street itself, and include cul-de-sacs or small loops carrying 500 average daily trips.

ii. Residential major streets. Residential major streets are access streets that provide frontage for service and access to individual lots and may carry a small amount of through traffic from tributary residential minor streets. Residential major streets carry from 500 to 2,000 average daily trips. Lot frontage on residential major streets with average daily trips in excess of 1,000 should be restricted.

b. Determination of average daily trips. For the purpose of classifying and designing residential streets, the average daily trips carried by a street shall be determined by applying trip rates from the most current Institute of Transportation Engineers Trip Generation Manual or other acceptable estimates approved by the traffic engineer.

c. Improvement design. Interior residential streets, except as provided in section 21.08.050E, shall be improved in accordance with Table 21.08-3 and Table 21.08-4.

TABLE 21.08-3: PAVED RESIDENTIAL STREETS, MINIMUM STANDARDS
A.D.T.2	Street Section1 (feet)		Number of Lanes		Design Speed3 (mph)4	Right-of-Way (feet)	Spillover Parking5	Application
	Standard	Optional	Moving	Parking
0—75 Residential minor	31		2	1	20	60	No	Culs-de-sac, low-volume residential streets
		24	2	0	20	60	Yes
76—300 Residential minor	31		2	1	25	60	No	Residential minor streets, culs-de-sac and small loops
		24	2	0	25	60	Yes
301—600 Residential minor	33		2	2	25	60	No	Residential minor streets, loop streets, high-volume culs-de-sac
		24	2	0	25	60	Yes
601—1,000 Residential major	33		2	2	25	60	No	Residential major streets, loop streets and high-volume culs-de-sac
		28	2	1	25	60	Yes
1,001—2,000	38	24	2	0	25	60	Yes	Residential limited access
			2	2	30	60	No	Residential subconnector
		38	36	0	30	60	Yes	No on-street parking permitted

Notes:

¹ Street dimensions are from back of curb.

² See § 21.08.050D.1.b, Determination of Average Daily Trips.

³ Horizontal curve design of residential streets requires best judgment of planners and engineers in addition to design analysis.

⁴ Design speed (not posted speed) for vertical and horizontal curves.

⁵ Spillover parking; homeowners' association required. See § 21.08.050E below.

⁶ Center turning lane required.

TABLE 21.08-4: STRIP-PAVED STREETS, MINIMUM STANDARDS
A.D.T.	Street Section7, 9 (feet)	Design Speed8 (mph)	Right-of-Way (feet)	Application
0—500	20	20	50	Residential loop streets, rural peripheral/access roads
501—1,000	24	25	50	Residential loop streets, urban peripheral/access roads
1,001—2,000	24	25	60	Major residential streets

Notes:

⁷ Dimensions are from edge of pavement.

⁸ Design speed (not posted speed) for horizontal and vertical curves.

⁹ Street sections require two-foot shoulders with ten-and 12-foot driving lanes, respectively.

2. Commercial and industrial interior streets. Commercial and industrial interior streets shall be improved in accordance with table 21.08-5 below:

TABLE 21.08-5: CLASS A COMMERCIAL AND INDUSTRIAL STREETS, MINIMUM STANDARDS
Street Section10 (feet)	Number of Lanes		Design Speed11 (mph)	Right-of-Way (feet)	Application
	Moving	Parking
33	2	0	30	60	No on-street parking
40	2	212	30	60	Commercial/industrial streets
47	3(1TL)	0	35	60	Major commercial/industrial streets; no on-street parking permitted; parking shall be provided off-street; turning movements when traffic warrants

Notes:

¹⁰ Street dimensions are from back of curb.

¹¹ Design speed (not posted speed) for vertical and horizontal curves.

¹² Parking may be provided off-street when a planter strip is used.

E. Optional residential interior streets.

1. Residential interior streets shall provide for on-street parking unless the platting authority finds it is practical to substitute spillover parking for on-street parking in accordance with subsection E.2 below. If the platting authority so finds, residential interior streets may be improved in accordance with this section and Table 21.08-3.

2. The platting authority may find that it is practical to substitute spillover parking for on-street parking only in residential subdivisions containing at least five acres or 25 dwelling units with a homeowners' association that is responsible for operating and maintaining spillover parking facilities.

3. Spillover parking substituted for on-street parking shall conform to the design standards in Section 21.07.090, Off-Street Parking and Loading, shall be a designated common area owned and administered by the homeowners' association, and shall not be located within an individually owned lot or tract. The design of spillover parking lots shall be approved by the traffic engineer. The spillover parking lot shall be shown on the plat, and a plat note shall be provided limiting the use of that area to spillover parking. Spillover parking lots shall not be counted toward required open space requirements. Spillover parking spaces shall be provided for each lot fronting on a street without on-street parking under the following formula, using the maximum residential density permitted for the lot by its zoning district.

TABLE 21.08-6: ADDITIONAL SPILLOVER PARKING SPACES REQUIRED FOR EACH LOT FRONTING ON AN OPTIONAL RESIDENTIAL INTERIOR STREET WITHOUT ON-STREET PARKING
Residential Use	Number of Spaces Per Unit
Dwelling, single-family detached	1.0
Dwelling, single-family attached or two-family	0.5
Dwelling, multifamily, or townhouse	0.25 managed guest spaces per multifamily dwelling with single-family or two-family style construction 0.15 managed guest spaces per townhouse dwelling or multifamily dwelling with townhouse-style construction 0.10 managed guest spaces per other multifamily dwelling

F. Access streets, peripheral streets, and half streets.

1. Access streets. The platting authority may require access streets when it finds that they are necessary for the efficient flow of traffic or for emergency vehicle access. The platting authority shall determine the length of the access street that the subdivider shall improve. Access streets shall be improved in accordance with Table 21.08-4.

2. Peripheral streets.

a. The platting authority may require the improvement of peripheral streets when it finds that they are necessary for the efficient flow of traffic or for emergency vehicle access.

b. Peripheral streets whose improvement is required under this subsection shall be improved in accordance with Table 21.08-4, provided that peripheral streets used for access to individual lots shall be improved in accordance with Tables 21.08-3 and 21.08-5.

3. Half streets. The municipal engineer or the platting authority may require the improvement of an access street or a peripheral street to a half street standard in the urban area in accordance with the half-street standards in the Design Criteria Manual, if underground utilities will be installed before street construction, or if no utilities are anticipated under the street section.

G. Curbs and Gutters. Where required, the subdivider shall construct curbs and gutters in accordance with the Design Criteria Manual and Municipality of Anchorage Standard Specifications (MASS), or, in the case of a state-maintained road, the current standard specifications of the state department of transportation and public facilities. Curbs shall be of the MASS Curb Type 1.

1. Exceptions.

a. Curb and gutter within the arc of a residential scale cul-de-sac may be of the rolled curb variety, as identified in the MASS (Curb Type 2).

b. MASS Curb Type 2 (rolled curb) may be provided for residential minor streets as defined in section 21.08.050D.1.a.i, and existing subdivisions without sidewalks per Section 21.08.050H; unless the portion of the street and the side for this exception is on, or expected to be on, a preferred route for safe routes to schools as determined by the traffic department.

H. Pedestrian facilities.

1. Sidewalks.

a. Sidewalks are required as determined by the transportation and connectivity standards in Section 21.07.060.

b. Sidewalks shall be improved in accordance with Table 21.08-7 below.

c. Sidewalks at bus stops shall comply with the specifications of the Design Criteria Manual.

2. Walkways.

a. Walkways are required as determined by the transportation and connectivity standards in Section 21.07.060.

b. Walkways shall be improved in accordance with Table 21.08-7 below, as determined by the platting authority.

c. Walkways in dedicated pedestrian easements may be improved or unimproved, as determined by the platting authority.

3. Pathways.

a. Pathways shall be located and constructed as determined by the Anchorage Non-Motorized Transportation Plan: Pedestrian Plan, the Anchorage Non-Motorized Transportation Plan: Bicycle Plan, and other adopted municipal plans.

b. Where a pathway and a sidewalk are co-located, the facility shall be constructed according to the specifications for a pathway.

4. Trails. Trails shall be located and constructed as determined by the Areawide Trails Plan and other adopted municipal plans.

TABLE 21.08-7: MINIMUM SIDEWALK, WALKWAY, AND TRAIL IMPROVEMENTS
Type of material	Minimum width	Separation from curb	Right-of-way	Notes
Sidewalks
4″ PCC	5	0	N/A	As a general rule, sidewalks should only be attached to the curb where on-street parking is allowed.
4″ PCC	5	7	N/A
Pavers	5	0 or 7	N/A	Decorative concrete or brick pavers
Walkways
4″ PCC	5		N/A	Walkways through commercial developments as required by §§ 21.07.060 and 21.07.090 are generally not located in easements
4″ PCC	5		10″	Not recommended where peat is surcharged
1½″ AC	5		10″	Generally used for improved walkways creating through-block connections; between cul-de-sac bulbs; connecting to parks, trails, other open space
Gravel	5		10″	May be used in class B improvement areas
Unimproved			10″
Pathways
1½″ AC	6	7
Trails
1½″ AC	See Trails Plan	7
Gravel		7		For class B improvement areas or nature trails
Unimproved				Generally for existing historical trails or trails through parks and open space

I. Street lighting.

1. Street lighting apparatus shall meet municipal standards for materials and design and be provided with underground power. The location of the streetlight poles shall be approved by the traffic engineer and shall comply with standards contained in the Design Criteria Manual.

2. Street lighting constructed for collector streets located in rural zones defined as class B improvement areas in Table 21.08-1 shall be non-continuous and shall provide the collector (low) level lighting specified in Table 5.1 of the Design Criteria Manual at intersections. Lighting may also be considered on a case-by-case basis, when necessitated by specific safety issues, in the following areas: (1) crosswalks in established school zones; (2) public access approaches to schools and emergency services stations; (3) designated at-grade crossings of separated pathways; (4) non-motorized underpass tubes and tunnels; (5) left turn storage bays if using raised or flush medians; and (6) areas where crash rates exceed statewide averages and the night-to-day crash ratio is 2:1 or greater. For the purpose of this rural lighting standard, a driveway is not an intersection.

J. Traffic control devices. Traffic and street name signs and traffic signals shall be installed in accordance with the requirements of the traffic engineer and the Alaska Traffic Manual, per the requirements of AS 28.01.010.

K. Monuments. Monuments and lot corner markers for determining the boundaries of subdivisions and lot corners shall be set by a professional registered land surveyor licensed by the state of Alaska. Survey monumentation shall conform to such additional standards as the municipal surveyor may establish by regulation under AMC Chapter 3.40.

L. Drainage system. A drainage system approved by the municipal engineer, including necessary storm drainage facilities, drain inlets, subdrains, footing drain stub-outs, manholes, culverts, bridges and other appurtenances, shall be installed. The design of the drainage system shall provide for the preservation of designated high-quality wetlands critical to water table levels and wildlife habitat within and surrounding the subdivision, shall protect the water quality and the re-charge of groundwater and surface watercourses, and shall comply with the following standards:

1. No surface water drainage from the subdivision shall empty into a sanitary sewer; or directly, without treatment and energy dissipation, into a creek or stream channel.

2. The size, design, and construction of drainage structures shall conform to the Design Criteria Manual.

3. Where a subdivision is traversed by a watercourse, drainage way, channel, or stream, a storm water or drainage easement shall be provided that substantially conforms with the lines of such watercourse, plus additional width that is adequate and necessary to convey expected storm flows and/or storm water drainage facilities. Streets paralleling such easement may be required in connection therewith. Lakes, ponds, creeks, and similar areas will be accepted for maintenance by the municipality only if sufficient land is dedicated as a public recreation area or park or if such area constitutes a necessary part of the storm water drainage control system.

4. The municipality shall accept no responsibility to maintain any storm drainage structures, except for those lying within a municipal right-of-way, traversing municipally owned property, authorized by permit on state or federal land, or constructed in a publicly dedicated drainage easement of sufficient width to allow access.

5. The drainage system shall comply with the standards set forth in Section 21.07.040, Drainage, Erosion and Sediment Control, Storm Water Runoff, and Prohibited Discharges.

6. Unless waived by the municipal engineer, footing drain stub-outs shall be provided for each lot where there is a storm drain system.

M. Telecommunication and electric facilities.

1. All new telecommunication and electric lines shall be installed in accordance with the specifications of the municipality and the utility providing the service.

2. All new telecommunication and electric utility distribution lines, as defined in Chapter 21.15, shall be placed underground:

a. As required by Section 21.07.050, Utility Distribution Facilities; and

b. As required by the platting authority in areas with patterns of development similar to those where Section 21.07.050 requires that utility distribution lines be placed underground.

N. Water supply facilities.

1. Access to public water system.

a. If the platting authority requires that a subdivision be served by a public water system, the subdivider shall install the system in accordance with the requirements of the state department of environmental conservation and the most current edition of the Design Criteria for Sanitary Sewer and Water Improvements of the municipal water and wastewater utility.

b. Where connection to public water supply systems is required, such systems shall be dedicated to the municipality for operation and maintenance, thus allowing for the orderly expansion of the municipality, its water systems, and fire protection services that protect the health and property of the citizens of the municipality.

2. No access to public water system.

a. If the subdivision has no access to a public water system, the platting authority shall require either wells on individual lots or a water system for the common use of the lots in the subdivision, if site conditions require such a system.

b. If wells on individual lots are authorized, the subdivider need not install water supply facilities. A well serving an individual lot shall conform to the requirements of the municipal on-site water and wastewater program. A common water system serving a portion of the subdivision shall not preclude individual wells for the remaining lots.

c. If a common system is required, the subdivider shall install the system in accordance with the requirements of the state department of environmental conservation and the specifications of the municipal water and wastewater utility.

O. Sanitary sewer facilities.

1. Access to public sewer system.

a. If the platting authority or provisions of law require that a subdivision be served by a public sewer system, the subdivider shall install the system in accordance with the requirements of the state department of environmental conservation and the most current edition of the Design Criteria for Sanitary Sewer and Water Improvements of the municipal water and wastewater utility.

b. Where connection to public sanitary sewer systems is required, such systems shall be dedicated to the municipality for operation and maintenance, thus allowing for the orderly expansion of the municipality and its sanitary sewer system, which protects the health of the citizens of the municipality.

2. No access to public sewer system.

a. If the subdivision has no access to a public sewer system, the platting authority shall require either a sewer system for the common use of the lots, or sewage disposal systems serving individual lots, whichever is more suitable.

b. If site conditions require a sewer system for the common use of lots in the subdivision, the subdivider shall install such system in conformance with the requirements of the state department of environmental conservation and the municipal water and wastewater utility.

c. If the platting authority authorizes sewage disposal systems serving individual lots, the subdivider need not install sewer facilities. In such case, the minimum lot size requirements of AMC Title 15 shall apply. The systems shall conform to the requirements of the municipal on-site water and wastewater program.

P. Natural gas facilities. All new natural gas facilities installed pursuant to this section shall be installed in accordance with the standard specifications of the municipality and the utility providing the service.

Q. Erosion and sedimentation control. All grading, excavating, and removal or destruction of natural topsoil, trees, or other natural vegetation shall conform to an erosion and sedimentation control plan prepared by the subdivider and approved by the department of public works before the work may commence. The plan shall conform to the requirements of Section 21.07.040, Drainage, Erosion and Sediment Control, Storm Water Runoff, and Prohibited Discharges, as well as municipal guidelines and policies contained in the Soil Erosion and Sediment Control Manual, and any other applicable guidelines and policies approved by the department of public works.

R. Landscaping. The subdivider shall be responsible for the provision of landscaping required under Section 21.07.080, Landscaping, Screening, and Fences, except the tree provisions of section 21.07.080F.8, and it shall be installed by the subdivider or guaranteed under the provisions of section 21.08.060E.

S. Soil cleanup standards. Any soil contamination regulated by the State of Alaska Department of Environmental Conservation (DEC) or its successor shall be cleaned up in accordance with the applicable standards promulgated and utilized by the DEC. Any cleanup required under this section shall be approved by DEC. In subdivision plat areas for dedication, the municipality:

1. Shall not require clean up to any greater extent than the standards set forth in this section; and

2. May accept dedication of lands that are subject to institutional controls.

(AO 2012-124(S), 2-26-2013; AO 2013-117, 12-3-2013; AO No. 2013-89(S-1), § 1, 10-22-2013; AO No. 2016-131, § 3, 11-15-2016; AO No. 2017-176, § 11, 1-9-2018; AO No. 2020-38, § 9, 5-28-2020; AO No. 2021-71(S-1), § 1, 3-22-2022; AO No. 2021-74(S), § 1, 5-10-2022; AO No. 2024-24, § 6, 4-23-2024)

§ 21.08.060 Subdivision agreements.

A. Agreement required; application; contents.

1. Agreement required. Before a final plat for a subdivision where improvements are required under Section 21.08.050 is approved or filed, the subdivider shall enter into a subdivision agreement with the municipality in accordance with this section.

2. Application. Application for a subdivision agreement shall be made to the department. The application shall include a copy of the platting summary of action, a copy of the preliminary plat, a tentative schedule of all proposed construction of public improvements and utilities, and an engineer's estimate of the cost of each required public improvement. The engineer's estimate shall be based on the most current average of unit bid prices for capital improvement projects, as tabulated annually and published by the municipal engineer. The municipality may require a showing of the subdivider's financial responsibility.

3. Contents. Except as provided in subsection A.4 below, the subdivision agreement shall include but need not be limited to the following provisions:

a. A designation of the public improvements required to be constructed.

b. The construction and inspection requirements of the municipality or utility for which the improvements are constructed.

c. The time schedule for completing the improvements.

d. The performance guarantee required by section 21.08.060G.

e. A schedule for any payments required under this section.

f. The allocation of costs between the municipality and the subdivider for required public improvements.

g. The warranty required by section 21.08.060I.

h. The consent of the subdivider for the ownership of specified public improvements to vest with the municipality upon final acceptance by the municipality.

i. A warranty that the subdivider has title to the subdivision property and the authority to execute the subdivision agreement.

j. Where the subdivision is within the flood hazard area, a requirement that the subdivider will submit certification of floodproofing, information on the elevation of the lowest habitable floor, and information on the elevation to which the structure is floodproofed, for each building or structure to be constructed as part of the subdivision agreement.

k. A provision requiring the subdivider to submit plans, specifications, descriptions of work, the limits of the work area, the methods to be employed, a traffic control plan, and any other pertinent data and information necessary for the building official to evaluate the proposed installation.

l. A provision that all designs conform to the Design Criteria Manual, and that all work shall be performed pursuant to the Municipality of Anchorage Standard Specifications.

m. A provision that work shall not commence until plans have been approved by the building official and notice to proceed is given.

n. A provision requiring the subdivider to provide timely notice to the building official or other municipal official identified in the agreement of any soil contamination, if known or upon discovery during development, that requires cleanup pursuant to section 21.08.050S, and requiring such cleanup.

4. Exceptions.

a. If the subdivider elects to complete and obtain acceptance of all required public improvements before the approval or filing of a final plat for the subdivision, the subdivision agreement need not include the guarantee provisions specified in items 3.c and d above.

b. If the subdivider is a governmental unit, the subdivision agreement need not include the guarantee required by 3.d above.

B. Approval by assembly. Approval by the assembly shall be required to enter into those subdivision agreements where municipal participation in the cost of the required public improvements is estimated to be $30,000.00 or more.

C. Time limit for completion of improvements.

1. The building official shall determine the time duration of the subdivision agreement, which shall not be less than two years nor more than three, based on the size, complexity, and possible phasing of the subdivision. The improvements required under the terms of the subdivision agreement shall be fully completed and accepted for warranty within that time period. However, before the expiration of the time allowed for completion, the subdivider may request a time extension from the building official. The building official may grant one time extension, up to two years in length, upon a showing of good cause by the developer and provided such extension does not unreasonably impact adjacent properties or the general public. The building official does not have the authority to modify conditions placed by the platting authority. The building official may refer any extension application to the platting board if the project is in default or he or she deems further or more extensive analysis and public comment concerning the continuation may be needed. In considering whether an extension should be granted, the following shall be considered: the manner in which safety hazards, drainage problems, sanding, snow removal, grading, and other matters will be handled during the extension period. Performance conditions may be imposed on the extension to ensure that such matters are adequately handled.

2. Requests for subsequent two-year time extensions require platting board approval. All time extensions shall be conditioned to require provision of an adequate performance guarantee when the existing guarantee is inadequate.

D. Payment of costs of required improvements outside the anchorage roads and drainage service area.

1. Outside of the Anchorage Roads and Drainage Service Area, the subdivider/developer shall pay 100 percent of all costs associated with construction, including but not limited to design, engineering, project administration and inspection, testing, surveillance, related bank fees and interest payments, fair market value of right-of-way, as well as all work, labor, and materials furnished for the construction of required improvements. The exception shall be those utilities whose tariffs provide cost participation.

2. The subdivider shall retain an independent registered engineer who has no financial interest in the development, to inspect and test the improvement construction. The engineer shall maintain in good standing professional liability insurance in the amount of $1,000,000.00 during the term of the agreement. Policies written on a "claims-made" basis shall have a two year tail of coverage from the completion of the subdivision agreement term. The required insurance policy shall provide for no less than 30 days advance notice to the municipality prior to cancellation.

E. Payment of costs of required improvements inside the Anchorage Roads and Drainage Service Area. The cost of any public improvement shall be defined to include the cost of design, engineering, contract administration, inspection, testing, and surveillance as well as all work, labor, and materials furnished for the construction of the improvement. The subdivision agreement shall provide for the apportionment of the cost of required public improvements between the municipality and the subdivider as follows:

1. Administrative and recording costs relating to public improvement guaranties. The subdivider shall pay 100 percent of all costs incurred in supplying and administering any method of public improvement guarantee provided for in this Section 21.08.060.

2. Inspection, surveillance, and testing.

a. The subdivider shall pay 100 percent of all costs relating to any inspection, surveillance, and testing by the municipality, necessary for warranty acceptance of any required public improvement or during the warranty period. Surveillance shall be performed by the municipality during the course of construction and up to the point of final acceptance of the completed project.

b. The subdivider shall retain an independent registered engineer who has no financial interest in the development, to inspect and test the improvement construction. The engineer shall maintain in good standing professional liability insurance in the amount of $1,000,000.00 during the term of the agreement. Policies written on a "claims-made" basis shall have a two-year tail of coverage from the completion of the subdivision agreement term. The required insurance policy shall provide for no less than 30 days advance notice to the municipality prior to cancellation.

3. Administration of agreement. The subdivider shall pay 100 percent of all costs of plan review, agreement administration, and attendant costs.

4. Arterial and collector streets. Reasonable costs incurred in the construction of a street designated on the Official Streets and Highways Plan (OS&HP) as a collector, arterial, or greater shall be apportioned as specified in subsections E.4.a through d below. For purposes of this subsection, construction costs means only those costs associated with construction, design engineering, project administration and inspection, related bank fees and interest payments, and fair market value of right-of-way dedicated to the street in excess of 70 feet.

a. Interior collector streets. If a collector street lies within the subdivision, the municipality shall reimburse the subdivider a sum equal to the reasonable construction cost of building to the standard specified by the platting authority, less the estimated cost of construction in accordance with the residential standard approved by the platting authority under Tables 21.08-3 and 21.08-5, provided that:

i. When the subdivision agreement is executed:

(A) The street is programmed for improvement to the designated standard in the six-year capital improvement program; and

(B) Sufficient funds (bonds, designated state grants, or mil-levy) have been appropriated for reimbursement in the capital improvement budget for the current fiscal year; or

ii. When the preliminary plat of the subdivision is approved:

(A) Construction to the designated standard is required by the platting authority;

(B) Improvement to the designated standard is programmed in the six-year capital improvement program; and

(C) Sufficient funds (bonds, designated state grants, or mil-levy) have been appropriated for reimbursement in the capital improvement budget for the current fiscal year.

If the conditions set forth in subsections E.4.a.i or ii are not met at the time specified, then the total cost of construction required by the platting authority shall be borne by the subdivider.

b. Interior arterial streets. If an interior arterial or greater street is required to be constructed to arterial standards by the platting authority, the municipality shall reimburse the subdivider 100 percent of the reasonable construction cost subject to the availability of bond funds, state grants, or mil-levy funds appropriated for the construction of that street. If the platting authority has not required construction to arterial or greater standards, the subdivider shall construct the street to the standards required under section 21.08.050D and shall bear 100 percent of the construction cost.

c. Peripheral streets. If the subdivider is required to construct an abutting collector street, the municipality shall reimburse a sum equal to the reasonable construction cost of the standards specified by the platting authority less the estimated cost of construction in accordance with the residential standards under Table 21.08-4, subject to the conditions specified in subsection 4.a above. If a subdivider is required to construct an abutting arterial or greater street to arterial or greater standards, the municipality shall reimburse in a manner and subject to the conditions set forth in subsection b above. If the subdivider is not required to construct an abutting street to arterial or greater standards, the subdivider shall construct the street to the standards required under section 21.08.050F and shall pay 100 percent of the cost of construction.

d. Access streets. If the platting authority requires the construction of an access street under the authority of section 21.08.050F that is designated as a collector, arterial, or greater, the municipality shall reimburse a sum equal to the reasonable construction cost of the standard specified by the platting authority less the estimated construction cost in accordance with the residential standards under Table 21.08-4, subject to the availability of bond funds, state grants, or mil-levy funds appropriated for the construction of that street. If the platting authority has not required construction to collector or greater standards, the subdivider shall construct the street to the standards required under section 21.08.050F and shall pay 100 percent of the construction costs.

5. Other streets. Except as provided in subsection E.4, the subdivider shall pay 100 percent of the cost of streets within the boundaries of the subdivision. The subdivider shall additionally pay 100 percent of the cost of all peripheral streets and access roads except as provided in subsection E.4 whose construction may be required by the building official. The property within subdivisions that is later assessed by the municipality for final improvements to access and peripheral streets shall receive credit for the cost of salvageable improvements to those peripheral and access streets. Nonsalvageable improvements will not receive credit. Credit will be provided only when:

a. The municipality approved the award of the contract which included the work for which the credit is to be issued; and

b. The subdivider provided the municipality with a sworn notarized statement setting forth the distribution of the costs of salvageable improvements, which he utilized for purposes of establishing lot price, for each lot within his subdivision to which such costs were spread.

The credit will be applied as a reduction of assessment to each applicable lot, except that in no case will the amount of credit given to any lot exceed the amount of the assessment to that lot.

6. Curbs, sidewalks, and walkways adjacent to streets. The subdivider shall pay the cost of constructing curbs, and sidewalks and walkways adjacent to streets, in the same manner as the cost of constructing the streets to which they are adjacent as provided in subsections E.4 and 5.

7. Sidewalks and walkways not adjacent to streets. The subdivider shall pay 100 percent of the cost of constructing all sidewalks and walkways not adjacent to streets.

8. Storm drains, inlets, and manholes. The subdivider shall pay 100 percent of the cost of storm drains, inlets, and manholes necessary to serve the subdivision, provided that, within areas where the municipality provides drainage maintenance, the municipality shall reimburse the subdivider those costs attributable to oversizing required by the municipality. In those areas where the municipality does not maintain drainage facilities, the subdivider shall pay all costs, including those for any required oversizing.

9. Water improvements. If the subdivision is to receive water service from a public utility, the subdivider shall provide water facilities, including service connections to all lots, with cost participation as provided in the current approved tariff of the utility. If the subdivision is to receive water service from a community water system, the subdivider shall provide water facilities, including service connections to all lots, and pay 100 percent of the cost of those facilities.

10. Sanitary sewer improvements. The subdivider shall provide sanitary sewer facilities, including service connections to all lots, with cost participation as provided in the current approved tariff of the municipal sanitary sewer utility.

11. Electrical and telecommunication facilities. The subdivider shall provide electrical and telecommunication facilities with cost participation as provided in the current approved tariffs of the applicable utility companies.

12. Deferred utilities. When paved street or sidewalk improvements are installed prior to placement of traffic control devices and electrical and telecommunication cable placement, the subdivider shall, at appropriate crossings as directed by the municipality, provide any necessary underground conduit consistent with conduit size, type, and installations standards provided by the utility.

13. Street lighting. The subdivider shall pay the cost of street lighting apparatus in the same manner as the cost of constructing the streets to which it is adjacent as provided in subsections E.4 and 5.

14. Traffic control devices. The subdivider shall pay 100 percent of the cost of traffic control devices. Traffic control devices, except electric-operated traffic signals, shall be installed prior to any structure being occupied in the subdivision.

15. Landscaping. The subdivider is responsible for required landscaping as stated in section 21.08.050R. Landscaping shall meet the standards of Section 21.07.080, Landscaping, Screening, and Fences.

F. Subsequent Development Reimbursement. (Reserved)

G. Guarantee of completion of improvements required; amount; methods.

1. Guarantee required. To ensure the installation of required public improvements that are not accepted at the time the final plat is filed, the subdivision agreement shall require the subdivider to guarantee the completion of all such improvements by one or more of the methods specified in this section. The means of a guarantee may be changed during the guarantee period upon approval by the building official. The amount of the guarantee shall be determined on the basis of the subdivider's cost estimate. The guarantee shall remain in effect until warranty acceptance of the public improvements and the posting of an acceptable security for the warranty period.

2. Cost estimate; overrun allowance. The engineer's cost estimate shall state the estimated cost of completion for each required public improvement. Cost estimates for each required public improvement shall be approved by the department. For purposes of establishing the amount necessary for the guarantee of completion of public improvements, a percentage for overrun allowance shall be added to the total estimated cost of public improvements as follows:

TABLE 21.08-8: PERCENT FOR OVERRUN ALLOWANCE
Total Estimated Cost of Improvements	Percent for Overrun Allowance
$0.00—$500,000.00	20%
$500,000.01—$1,000,000.00	15%
More than $1,000,000.00	10%

3. Methods. The subdivision agreement shall include one or more of the following methods to guarantee the construction of required public improvements:

a. Performance bond. The subdivider may elect to provide a surety bond from a company authorized to do such business in the state. The bond shall be in a form acceptable to the municipal attorney and in an amount equal to the estimated cost of all required public improvements, plus an overrun allowance as provided in subsection G.2 above. The bond shall be payable to the municipality if any required public improvements are not finally accepted in accordance with the provisions of this title, and shall be posted by no person other than the subdivider or a contractor obligated by written contract to the subdivider for construction of all the required public improvements. In the event a contractor posts the bond, the subdivider and the municipality may be dual obligees under mutually agreed terms.

b. Deposit in escrow. The subdivider may elect to deposit a cash sum equal to the estimated cost of all required public improvements plus overrun allowances as provided in subsection G.2 above, either with the municipality or in escrow with a responsible financial institution authorized to do such business in the state. In the case of an escrow account, the subdivider shall file with the municipality an escrow agreement that includes the following terms:

i. Funds of the escrow account shall be held in trust until released by the municipality and may not be used or pledged by the subdivider as security in any matter during that period other than payment for the improvements.

ii. In the case of a failure on the part of the subdivider to complete any improvement within the required time period, the institution shall immediately make all funds in such account available to the municipality for use in the completion of those improvements.

c. Letter of credit. The subdivider may elect to provide from a bank or other responsible financial institution authorized to do such business in the state an irrevocable letter of credit. Such letter shall be filed with the municipality and shall certify the following:

i. That the creditor irrevocably guarantees funds in an amount equal to the estimated cost of all required public improvements plus overrun allowances as provided in subsection G.2 above, for the completion of all such improvements; and

ii. That in the case of failure on the part of the subdivider to complete any specified improvements within the required time period the creditor shall pay to the municipality immediately and without further action such funds as are necessary to finance the completion of those improvements up to the limit of credit stated in the letter.

H. Release of guarantee of improvements.

1. Inspection shall be made by the municipality prior to acceptance of the improvements for warranty. The municipality shall have 14 days to complete the inspection and provide a list of deficiencies, except that the building official may extend the 14-day period for unusual circumstances such as extreme weather. The 14-day period shall begin on the day the municipality receives written notice from the subdivider that the subdivider's own comprehensive inspection has confirmed that construction of all required improvements is complete, all applicable subdivision agreement requirements are fulfilled, and the project is ready for municipal inspection.

2. After the initial municipal inspection provided for in subsection H.1 has been completed and all listed deficiencies noted in the initial municipal inspection and provided in writing to the subdivider have been corrected, the subdivider shall notify the municipality in writing and the municipality shall perform a final inspection of the listed deficiencies within seven days of receiving the notification, except that the building official may extend the seven-day period for unusual circumstances such as extreme weather.

3. If the final inspection reveals uncorrected listed deficiencies that were identified in the initial inspection that was provided to the subdivider in writing prior to the final inspection, this procedure shall be repeated until all deficiencies noted in the initial inspection have been corrected. The warranty period shall begin after all the deficiencies in the initial inspection have been corrected.

4. Excepting any new deficiency or deficiencies resulting from the subdivider's activities correcting the deficiency or deficiencies identified above, any new deficiencies that were not discovered and identified in writing and delivered to the subdivider during the initial inspection, but are found in any final or any continuing inspection, shall be noted and corrected by the subdivider during the warranty period. However, these deficiencies shall not delay the commencement of the warranty period.

5. In addition to correcting deficiencies in the work, and prior to being placed on warranty, the subdivider shall also submit:

a. A complete record of the engineer's daily inspection reports;

b. Copies of test results;

c. Reproducible mylar record drawings of the facilities constructed;

d. Acceptance letters from electric and telephone utilities that all lots have service available;

e. As applicable, acceptance letters from gas and water/wastewater utilities that all lots have service available;

f. Certificate of monumentation;

g. Certificate of compliance that all suppliers and subcontractors have been paid;

h. Payment in full for municipal billings associated with the subdivision agreement; and

i. A deposit as required by AMC Section 24.20.040D to cover administrative and inspection costs during the warranty period.

6. When all deficiencies in the work have been corrected and all items listed in subsection H.5 above have been submitted, reviewed, and accepted, the project shall be eligible to be placed on warranty.

7. The municipality shall release the obligation for performance guarantees upon the acceptance of the improvements for warranty, together with the posting of adequate security for warranty.

8. The municipality may refuse to release the obligation for any particular public improvement if the subdivider or contractor is in present or imminent default in whole or in part on the completion of any public improvement or warranty covered by the subdivision agreement.

I. Improvement warranty.

1. The subdivider shall warrant and guarantee that required public improvements constructed under the agreement will remain in good condition and meet operating specifications for two years, commencing with warranty acceptance of each public improvement when it is completed. Such warranty includes defects in design, workmanship, materials, and any damage to improvements caused by the subdivider, his or her agents, or others engaged in work to be performed under the subdivision agreement. If the building official deems appropriate, extensive repairs or modifications made during the warranty period may extend the duration of the warranty period for those repairs or modifications only. The subdivider shall not be responsible for cleaning, snow removal, ditching, grading, dust control, or similar activities during the warranty period. Nothing in this title, however, is intended to waive the requirements of AMC chapter 24.80, pertaining to miscellaneous use provisions.

2. To secure the warranty:

a. The guarantee of performance provided for in subsection G shall remain in effect until the end of the warranty period. If the guarantee is a performance bond posted by a contractor, the bond cannot secure the warranty unless the subdivider and contractor, by written agreement, elected this option at the time the performance bond was posted; or

b. The subdivider shall furnish the municipality with a corporate surety bond, cash deposit, or letter of credit in an amount equal to a percent of the total construction costs as set forth in this subsection. This security shall guarantee the payment of any reconstruction or repair costs that may be undertaken due to failures occurring during the warranty period. Responsibility for identifying the necessity of repairs or reconstruction of the improvements shall rest with the municipality.

TABLE 21.08-9: PERCENT TO SECURE WARRANTY
Total Construction Cost	Percent to Secure Warranty
$0.00—$500,000.00	10%
$500,000,01—$1,000,000.00	7½%
More than $1,000,000.00	5%

c. A governmental units acting as the subdivider, in executing the subdivision agreement, agrees:

i. To the warranty terms in this section and its subdivision agreement, but need not post a guarantee, and

ii. Shall, upon breach of the warranty, either correct the deficiencies or pay the municipality's costs, in accordance with subsection J.

J. Correction of deficiencies under warranty.

1. Within 30 days, or a reasonable extension at the sole discretion of the building official, of notification by the municipality of the need for repair or reconstruction, the subdivider shall correct the deficiencies, satisfactory to the municipality. Such notification shall be made by certified mail. If the subdivider fails to repair or reconstruct the deficiency within the time specified in this section, the municipality will make the repair at the subdivider's sole expense. The municipality may then bill the subdivider for the cost of the repair and associated administrative costs, or declare the bond or deposit forfeited.

2. Notwithstanding subsection J.1 above, if the subdivider or the subdivider's engineer retained through the warranty period first identifies need for repair or reconstruction, the subdivider shall notify the municipality by certified mail, and the subdivider shall make the repair or reconstruction with authorization (in lieu of the above notification) from the municipality.

K. End of warranty period.

1. The municipality shall inspect the required improvements and provide a list of deficiencies to the subdivider no later than 30 days before the end of the warranty period, except that the building official may extend this time due to inappropriate weather or other conditions that impede complete inspection.

2. All deficiencies identified in the warranty period shall be corrected, inspected, and approved within 30 days, except that the building official may extend the 30-day period for unusual circumstances or inappropriate weather. The municipality is under no obligation to release any remaining security if the subdivider fails to correct any identified deficiencies.

3. Upon final acceptance, the municipality will release the remaining security within 90 days.

4. If the municipality does not timely inspect and provide a report as required in K.1 above, the warranty period ends.

L. Default. If the subdivider defaults on any obligation to construct required public improvements or the obligation to warrant and repair such improvements, the municipality may demand immediate payment on the performance or warranty guarantee. In the case of a performance bond, deposits in escrow, or letter of credit, the municipality may demand immediate payment of a portion of all sums obligated for the performance or warranty of any improvement. All funds received by the municipality shall be used for any construction, repair, or reconstruction necessary to ensure that:

1. All required public improvements are built to specifications necessary to receive warranty acceptance; and

2. The improvements remain in good condition for the completion of the warranty period. The municipality may use guarantee funds for the construction, repair, or maintenance of required public improvements from the date of initial default until three years after the funds have become available to the municipality for such use, except that no use shall be made of the funds later than two years after satisfactory completion and warranty acceptance of the work. Following either: (1) the warranty acceptance of all public improvements and posting of the warranty security, or (2) final acceptance, or (3) the three-year period provided for in this subsection, the municipality shall pay to the subdivider all guarantee funds which were not used or obligated for the completion of the improvements.

M. Agency coordination. Upon receipt of notification of violation or concern by municipal departments or outside agencies, the building official may suspend approval on work authorized through the subdivision agreement until such time that the issue is resolved.

N. Standards may not be altered; enforcement of chapter. All provisions of this chapter are mandatory and may not be altered by the subdivision agreement. The obligations contained in this chapter shall be enforceable by methods of enforcement of ordinance as well as contract.

(AO 2012-124(S), 2-26-2013; AO 2013-117, 12-3-2013; AO No. 2015-60, § 2, 5-26-2015; AO No. 2021-74(S), § 2, 5-10-2022)

§ 21.08.070 Alternative residential subdivisions.

A. Purpose. This section offers three alternatives from conventional subdivisions for new residential neighborhoods: conservation subdivisions, cluster housing, and narrow lot housing. The intent of these options is to give flexibility to developers to respond to environmental conditions or market preferences.

Each alternative shall be considered through the platting process outlined in Section 21.03.200, Subdivisions.

B. Conservation subdivisions.

1. Purpose. A conservation subdivision is an alternative type of residential development in which the lots are allowed to be smaller in area or narrower than otherwise required in the zoning district, but in which the overall number of lots does not exceed the maximum number of lots allowed in a conventional subdivision by the zoning district. Conservation subdivisions are intended to create a more compact residential development to preserve and maintain open areas, high value natural lands, and lands unsuitable for development, in excess of what would otherwise be required by this title.

2. Applicability. The conservation subdivision option may be used on any parcel with a minimum of at least two acres in any residential district in which single-family housing is permitted, provided that the proposal is consistent with the requirements in this Section 21.08.070.

3. Conservation design process. Conservation subdivisions shall be approved through the procedure set forth in Section 21.03.200, Subdivisions and Plats.

4. Reduction in minimum lot area allowed. Conservation subdivisions may include one or more lots that do not conform to the minimum lot size or lot width requirements of Chapter 21.06, or the dimensional requirements of section 21.08.030K.1 and K.2, provided that:

a. The amount of any reduction in minimum lot size shall be used for common open space, pursuant to subsection B.6 below;

b. There shall be no more than one principal single-family structure per lot;

c. Front and rear setbacks interior to the subdivision are not less than half the depth required by the underlying zoning district, but side setbacks are not less than the width required by the underlying zoning district;

d. On any lot that is less than the minimum lot size of the underlying zoning district, the principal structure shall have a maximum floor area ratio of not more than 0.5;

e. In class A improvement areas, street sections shall have vertical curbs;

f. Driveways shall have a maximum width of 14 feet at the curb;

g. Where on-street parking is allowed, a minimum 20-foot separation distance between the curb returns of adjacent driveways shall be provided; and

h. Common open space with level 4 Screening landscaping shall be provided along any lot line abutting a residential neighborhood where any adjoining lot is greater than 150 percent of the average lot size along that lot line of the conservation subdivision. In class B areas this abutting landscaped open space area shall be 100 feet wide.

5. Lot coverage allowed. The maximum lot coverage requirements for lots in a conservation subdivision, as set forth in Chapter 21.06, may be increased by no more than 10 percent.

6. Minimum open space. The amount of lot size reduction of each lot shall, in total, be provided as common open space, except that under no circumstances shall the amount of common open space provided be less than 30 percent of the property shown on the subdivision plat. Open space shall be identified using the standards set forth in section 21.07.030D, private open space, standards, except that no portion of the land preserved as common open space may be located within the boundaries of an individual lot for residential development, or in a road right-of-way, and no portion of the land preserved as common open space may be less than 30 feet in its smallest dimension in class A districts or less than 100 feet in its smallest dimension in class B districts, or have less square footage than one-half of the square footage of the minimum lot size for that district. In order that all residents of a development have access, there should be, provided by the developer, a common pedestrian corridor leading into all common open space. Common open space areas in class B improvement areas shall remain undisturbed.

7. Dedication and recording. The required common open space shall be preserved from development in perpetuity through the use of a deed restriction or easement, and shall be conveyed to a property owners' association or other organization with responsibility for maintenance of the open space and the ability to collect assessments or dues for such purpose. The applicant shall submit proof that:

a. Such deed restriction or easement has been recorded at the district recorder's office; and

b. The property owners' association or other organization has been established before any building or land use permits for construction in a conservation subdivision shall be issued.

C. Cluster housing.

1. Intent.

a. A cluster housing development is a design technique that provides open space and other site amenities in a subdivision by permitting individual lots of less area than otherwise permitted in the underlying use district. The community receives the benefits of open space within subdivisions and land developers may provide subdivisions at a somewhat higher density than permitted by the underlying use district.

b. Cluster housing is intended to provide a development option particularly suited to tracts of land that include marginal areas. Marginal lands may include wetlands, steep slopes, or geophysical hazard areas. By clustering the overall number of units possible on the developable portion, construction and infrastructure costs may be lowered. Correspondingly, open space amenities are provided and environmentally sensitive lands are conserved.

c. It is also intended to provide a design option in transition density areas, where zones of different densities abut. Lower costs in subdivision development should be reflected in housing costs.

d. Cluster housing developments may include single-family detached and various types of attached housing.

2. General standards.

a. In addition to a preliminary plat, a cluster housing proposal shall include a site plan, to be approved by the platting authority.

b. No land use permits shall be issued until a final plat for the cluster housing development has been approved and filed in accordance with this title.

3. Maximum density and minimum site area.

a. There shall be no more than one principal structure per lot.

b. The maximum number of dwelling units permitted in the cluster housing development shall be based upon the following schedule. The density shall be calculated using gross acreage.

TABLE 21.08-10: MAXIMUM DENSITY FOR CLUSTER HOUSING SUBDIVISIONS
Zoning District	Dwelling Units Per Acre	Minimum Site Area (acres)13
R-1	5.0	2.5
R-1A	5.0	2.5
R-2A	10.0	1.5
R-2D	16.0	1.5
R-2M	19.0	1.5
R-3	20.0	1.0
R-4	24.0	1.0
R-4A	35.0	1.0
R-5	5.0	2.5
R-6	0.8	5.0
R-7	2.0	5.0
R-8	0.2	10.0
R-9	0.4	5.0
R-10	See § 21.04.020O.2	10.0
TA	As provided in the Turnagain Arm Comprehensive Plan	5.0
GR districts	As determined by the Platting Board	5.0

Note:

¹³ The minimum site area may be reduced by up to 5 percent to account for irregular lots or difficult sites.

4. Review of housing type. The pre-application submissions for a cluster housing development in the R-1 or R-1A zoning districts, more than 50 percent of whose dwelling units are attached, are subject to review and approval by the planning and zoning commission for compatibility with surrounding land use patterns.

5. Lot area and width. The applicant may propose lot areas and widths that are less than the minimum required by Chapter 21.06.

6. Maximum lot coverage. Maximum lot coverage for areas other than common areas is as follows:

a. Two common walls per dwelling unit: 70 percent.

b. One common wall per dwelling unit: 50 percent.

c. All others: 40 percent.

7. Minimum setbacks.

a. Minimum setbacks for the R-6, R-8, R-9 and R-10 zoning districts shall be as follows:

i. Front setback: 25 feet.

ii. Side setback: 10 feet.

iii. Rear setback: 20 feet.

b. Minimum setbacks for all other zoning districts shall be the same as the underlying district.

8. Common area.

a. General standards.

i. Development of the common area in accordance with an approved site plan and subdivision plat shall be guaranteed in the subdivision agreement.

ii. All areas of the common area not devoted to buildings, structures, parking areas, courts, walkways, improved areas for sport and game activities, and driveways shall be covered by one or more of the following: lawn grass, shrubbery, trees, or undisturbed indigenous vegetation.

iii. The space between and surrounding clusters is allocated to pedestrian circulation and open space.

b. Common open space.

i. In a cluster housing development, at least 30 percent of the site area shall be common open space. Environmentally sensitive features such as wetlands, natural drainage ways, steep slopes, ponds, lakes, creeks, streams, and the like may be included in the computation of open space provided towards this requirement. Private spaces, such as patios, decks, balconies, yards within individually owned lots, and the like are not included in the definition of common open space.

ii. Of the required common open space, at least 600 square feet per dwelling unit shall be provided as common usable open space within cluster subdivisions that are created with any lots less than 6,000 square feet in area.

c. Common usable open space. The cluster housing development shall have a common usable open space area with the following characteristics:

i. Shall not be less than 2,500 square feet.

ii. Shall have no dimension that is less than 30 feet.

iii. Shall be within a distance of 1,000 feet from every lot within the cluster subdivision.

iv. Shall not contain roads, parking facilities, driveways, storage, snow storage, service areas, wetlands, or water bodies (unless they provide or substantially contribute to a recreation area).

v. Shall have a slope equal to or less than five percent when the common usable open space area is 10,000 square feet or less. A common usable open space area of greater than 10,000 square feet may have slopes exceeding 15 percent on no more than ten percent of the area, unless the platting authority finds that a greater slope is consistent with the intent of this section.

vi. Except as provided in subsection c.iv above, shall be drained to carry away storm and seepage water.

vii. May be retained as natural vegetation. Improvements may include seeding with lawn grass or other seed mix approved by the planning division, with an established access to a source of water for maintenance. Improvements may also include pavement or other appropriate surfaces or complementary structures to allow for active outdoor recreation uses.

9. Homeowner's association.

a. A homeowner's association shall be established for all cluster housing developments. All owners of property within the cluster housing development shall automatically become members of the homeowner's association.

b. Any declaration under the Horizontal Property Regimes Act, common wall agreements, declaration of covenants, conditions and restrictions, and homeowner agreements proposed to be recorded to govern the use of land and structures within a cluster housing development shall be reviewed for conformity with this title by the director.

c. The responsibility for the operation and maintenance of the common area facilities shall reside with the homeowner's association.

10. Buffer landscaping. L2 buffer landscaping shall be planted along each lot line abutting a right-of-way designated for collector or greater capacity on the Official Streets and Highways Plan. The landscaping shall be maintained by the property owner or his or her designee.

D. Narrow lot housing.

1. Purpose. Narrow lot housing is a form of small-lot housing that provides fee simple, single-family home lots that are smaller than such lots created by right in various zoning districts, in order to provide more affordable housing choices. As narrow lot housing will be available and frequently used for infill development, there are increased design standards for narrow lot housing in order to mitigate the impacts of increased density on existing neighborhoods.

2. Applicability. Narrow lot housing is permitted in the R-2A, R-2D, R-2M, R-3, R-4A, R-5, and RO districts. The various applicable standards of Title 21 apply, unless specifically addressed and replaced below.

3. Approval process. Narrow lot housing shall be platted in accordance with Section 21.03.200C, and shall not be eligible for the abbreviated plat process.

4. Uses. Only detached single-family homes and customary accessory uses/structures may be located on narrow lots, except that ADUs and bed and breakfasts are prohibited accessory uses.

5. Size of narrow lot developments. The total contiguous area (including streets) developed with narrow lots shall be no greater than one acre.

6. Standards.

a. Lot area and width. Narrow lots shall be at least 30 feet wide, and no less than 80 feet long.

b. Setbacks. The setbacks of the underlying zoning district shall apply, as provided in Chapter 21.06, except that where an entire block is subdivided with narrow lots in a residential district, the principal structure may encroach into the front setback by up to ten feet.

c. Height. Structures are limited to 25 feet and two stories in height.

d. Lot coverage. For one-story structures, the lot coverage is 50 percent. For two-story structures, the lot coverage is 40 percent.

e. Floor area ratio (FAR). The principal structure on each narrow lot shall have an FAR of 0.5.

f. Access. Homes on narrow lots shall not be accessed from the street abutting the shorter end of the lot. Access shall be from an alley at the rear of the lot, or for corner lots, from a street abutting the longer side of the lot.

g. Number of lots created. No more than 12 narrow lots may be created abutting one another.

h. Design.

i. Mix of housing models. Any subdivision of three or more units shall have a mix of housing models, as determined during the building permit process, according to the following table:

TABLE 21.08-11 MIX OF HOUSING MODELS FOR NARROW LOT HOUSING
Number of units	Number of different models required
3—6	2
7—12	3
See § 21.07.110E.2 for how to determine a mix of housing models.

Where only two narrow lots are created, if the same design is proposed for both homes, the homes shall be constructed in a "mirror image."

ii. Primary entrance. Homes on narrow lots shall meet the standards of section 21.07.110E.3.

iii. Street-facing façade. Homes on narrow lots shall feature at least one design element from each of the following subsections: 21.07.110E.4.c.i, E.4.c.ii, and E.4.c.iii.

iv. Garages. Garages shall not be longer than 30 feet in length and shall be located facing the rear of the lot, or for corner lots, may face the secondary front setback.

v. Windows. Windows facing side lot lines are encouraged to be located in such a manner as to not be directly across from windows in neighboring narrow lot homes.

E. Unit lot subdivisions.

1. Purpose. The unit lot subdivision is intended to allow fee simple ownership of a dwelling unit within a multifamily development, simplifying the financing process for the developer, but not increasing the density allowed on the lot or changing the development standards.

2. Applicability. The unit lot subdivision process may be used within the R-2M, R-3, R-4, R-4A, RO, B-1A, B-1B, B-2C, B-3, gR-4, gR-5, gC-6, gC-7, gC-8, gC-9, CE-R-2M, CE-R-3, CE-RO, and CE-B-3 districts.

3. Approval process.

a. A unit lot subdivision shall be reviewed in accordance with AMC Section 21.03.200C. Review and Approval of Subdivision Plans.

b. Before filing an application, the applicant shall request a pre-application conference with the director, in accordance with section 21.03.020B.

c. In addition to the submittal requirements for preliminary plats, an application for a unit lot subdivision shall include a preliminary development plan, drawn to scale, which shall contain:

i. Property lines of the parent lot and the proposed unit lots.

ii. Setbacks of the parent lot.

iii. The footprint of any existing structures to remain, along with the distance to property lines and lot coverage calculations.

iv. The location and footprint for each proposed structure on each unit lot.

v. A delineation of the required open space.

vi. The driveway and parking locations, layout, dimensions, circulation, ingress and egress.

vii. The location, if applicable, of any buildings to be used in common by the residents of the housing development.

viii. The layout and dimensions of all pedestrian circulation facilities.

ix. A utility plan addressing water and wastewater in accordance with the current Design and Construction Practices Manual-DCPM, approved by AWWU.

x. Any other information the director finds necessary to ensure compliance with this title.

4. Uses.

a. In residential districts where unit lot subdivisions are permitted, the allowed uses are limited to the residential uses as shown in Tables 21.05-1, 21.09-2, and 21.10-4 as permitted in the applicable district.

b. In commercial and DT districts where unit lot subdivisions are permitted, only one unit lot within any parent lot may contain nonresidential uses. Unless authorized by the director, the unit lot containing the nonresidential uses(s) shall abut a street. The unit lot containing the nonresidential uses(s) may also contain a dwelling unit, in which case section 21.04.030G or H may apply.

c. Only one dwelling unit is permitted per unit lot.

5. Dimensional standards.

a. The standards of Tables 21.06-1, 21.06-2, 21.09-5, 21.09-6, 21.10-6, 21.10-7, and 21.11-4 apply to the parent lot.

b. No setbacks are required by this title on lot lines between unit lots, but setbacks may be required by title 23.

c. The lot size of the parent lot shall determine the maximum number of units permitted on the parent lot, in accordance with the dimensional standards tables.

d. Where a maximum floor area ratio (FAR) applies, it shall apply to the parent lot.

6. Design standards.

a. Open space requirements shall be provided in accordance with Section 21.07.030 and shall be applied to the parent lot, except that none of the open space is required to be common open space.

b. Drainage shall be designed for the parent lot. Design and construction on each unit lot shall comply with the approved drainage plan for the parent lot.

c. Snow storage shall be provided in accordance with section 21.07.040F and shall be applied to the parent lot.

d. Landscaping requirements shall be applied in accordance with Section 21.07.080 and shall be applied to the parent lot.

e. Refuse collection standards shall be applied in accordance with section 21.07.080G.2 and shall be applied to the unit lots.

f. The applicable residential design standards shall be applied in accordance with Section 21.07.110.

g. Where multiple unit lots abut a street, driveway cuts shall be minimized, either through shared access on the other side of the buildings from the street, or by shared driveways.

h. AWWU service standards shall be applied in accordance with AMC Chapter 26.40, Water Service and Chapter 26.50, Sewer Service.

i. All applicable design standards in Section 21.11.070 shall apply to parent lots in the DT districts.

7. Covenants, conditions, and restrictions.

a. A Homeowners' Association with covenants, conditions, and restrictions is required for each unit lot subdivision, in order to ensure the long term success, maintenance, cohesive appearance, and curb appeal of a small subdivision.

b. Prior to recording the final plat, the applicant shall provide access easements, joint use and maintenance agreements, and final covenants, conditions, and restrictions identifying the rights and responsibilities of property owners and/or the homeowners' association, complying with the requirements described below, in a form satisfactory to the director. The documents shall be reviewed and approved by the platting officer and AWWU, and shall then be recorded with the state recorders office.

c. Prior to recording the final plat, the applicant shall provide evidence that the Homeowners' Association has been incorporated pursuant to the laws of the State of Alaska.

d. The covenants, conditions, and restrictions shall provide authority for the Homeowners' Association to perform required maintenance, repairs, or replacement, to recover any costs incurred by the Homeowners' Association to maintain, repair, or replace components that are the responsibility of the unit lot owners which are visible from the exterior of the residence, due to a failure of individual owner of the unit lot to adequately maintain, repair, or replace these components.

e. The covenants, conditions, and restrictions shall identify/define areas and components which are the responsibility of the Homeowners' Association to maintain, repair and replace and areas and components which are the responsibility of the individual unit lot owners to maintain, repair, and replace.

f. In unit lot subdivision developments, the Homeowners' Association shall be responsible for maintenance, repair, and replacement of, including without limitation, shared landscaping; easements for: vehicle and pedestrian access, joint use and access, parking, open space, and similar areas; snow removal within shared areas and easements; on-site private utility and drainage infrastructure; and, except as provided in subsection 7.g below, exterior building components which are visible from outside the building including without limitation: roofs, siding, gutters, decks and porches, and other similar features. For purposes of this section, maintenance obligations of the Homeowners' Association need not include snow clearing and removal from the exterior building components.

g. For unit lot subdivisions where all units are detached units, the Homeowners' Association is not required to be responsible for exterior building components which are visible from outside the building including without limitation: roofs, siding, gutters, decks and porches, and other similar features. Per subsection 7.d above, the Homeowners' Association does have authority to perform required maintenance, repairs, or replacement and recover costs associated with maintenance, repairs, or replacement to exterior building components which are the responsibility of individual unit lot owners' and which are visible from the exterior of the residence.

h. The Homeowners' Association shall maintain in reserves, or in their operating budget, adequate funding for maintenance, repairs, and future replacement of the items and areas for which the Homeowners' Association is responsible per subsection 7.f above.

i. The Homeowners' Association shall perform all maintenance, repair, and replacement of the improvements that are the responsibility of the Homeowners' Association in accordance with applicable municipal codes and the covenants, conditions, and restrictions.

j. Individual unit lot owners shall perform all maintenance, repair, and replacement of the improvements that are the responsibility of the individual unit lot owners in accordance with applicable municipal codes and the covenants, conditions, and restrictions.

8. Existing development. Existing development may be subdivided through the unit lot subdivision process if it meets or can be made to meet the requirements of this title.

(AO 2012-124(S), 2-26-2013; AO 2013-117, 12-3-2013; AO No. 2017-75, § 3, 5-9-2017; AO No. 2020-38, § 9, 5-28-2020; AO No. 2020-93, § 3, 10-1-2020; AO No. 2021-89(S), § 15, 2-15-2022; AO No. 2023-42, § 7, 8-22-2023; AO No. 2024-24, § 6, 4-23-2024)