A. Purpose. It is the purpose of this section to establish regulations that recognize development of land in hilly or mountainous areas involves special considerations and unique situations which result from the slope of the land. These special considerations and unique situations include but are not limited to increased hazards to development from rock falls, storm water runoff, geologic hazards, increased limitations on vehicular travel, and increased difficulties in providing public services. In addition, steeply sloped lands introduce design limitations to roadways, cuts and fills, and building sites. In general, the more steeply the land slopes, the greater potential hazard and development limitation. Additionally, since hilly or mountainous areas within the City offer a desirable setting, visible to the entire City, they are a unique natural asset. It is intended through these regulations to preserve the visual integrity and character of hillside areas, while allowing reasonable development which is both safe and functional. Additional hillside development standards are included in Section 710 of the Zoning Ordinance.
B. Applicability. The provisions of this section shall be applicable to all preliminary plats in process, all final plats not recorded on the date of the enactment of this original chapter; and the division of all land in a hillside development area whether or not the parcels are two and one-half acres or more in area.
1. Special preliminary plat requirements.
a. A topographic map of existing terrain with contour intervals adequate to show the nature and variations in the terrain.
(i) Two-foot intervals for grades less than 15 percent.
(ii) Five-foot intervals for grades greater than 15 percent.
(iii) Elevations of critical spots, rock outcrops and special characteristics.
b. Where necessary to determine that lots will be usable, the Department may require a grading plan for each lot, in conformance with the Grading and Drainage Ordinance showing the natural topography of the total parcel to be platted, the location and size of all structures, the finish grade of all improvement locations, and the depth and extent of all cuts and fills.
c. A soils report by a licensed geologist or engineer may be required.
d. Location of existing and proposed preservation or conservation.
2. Special final plat requirements.
a. A final grading plan per dwelling unit which conforms to the requirements of the Development Review Manual and the Grading and Drainage Ordinance or individual lot grading plans at the time of the individual building permit.
b. A detailed topographic map at larger scale and closer contour intervals and suitable cross sections or profiles of areas where streets, driveways, buildings, utility, or grading construction is proposed.
c. Road profiles and cross sections at all significant changes in slopes; the cross section to show proposed and natural grade at the centerline of the road, the right-of-way line and the proposed building setback lines.
d. Locations of all building sites and proposed driveways if tract development; not required if custom home development but will be required when submitting individual lot grading plans.
3. Special design standards.
a. Street and private access way grades shall conform as closely as possible to natural topography, but shall not exceed 15 percent.
b. Street grades exceeding 12 percent shall have a maximum length of 600 feet.
c. Upon concurrence by the Department’s Traffic Engineer horizontal alignments may provide curves with less than 100 feet centerline radius.
d. Upon concurrence of the Department’s Traffic Engineer various designs for turning and backing type of cul-de-sacs may be substituted for circular turnarounds.
e. Upon concurrence of the Department’s Traffic Engineer required paving width of the traffic lanes may be modified when off-street parking bays are provided, developed, and paved in the public right-of-way.
f. Centerline of the paving may be offset from the centerline of the right-of-way to provide parking bays in the right-of-way.
g. Where bridle trails are approved, sidewalks may be replaced by the trails on the upgrade side of the right-of-way.
h. Vertical curbs shall be required on the downhill side of streets having grades of six percent or greater; other types of approved curb may be installed in lieu of conventional rolled or vertical curb elsewhere.
i. On a corner lot no grading shall be allowed which results in the ground level being increased so as to present an obstruction to vision above a height of three feet above the grade of either street within an area formed by the lot lines on the street sides of such lot and a line joining points on such lot lines located a distance of 33 feet from the point of their intersection.
j. Transverse street cross section with gutter on the uphill side may be used upon concurrence by the Planning and Development Director.
k. All cut and fill slopes shall be within the roadway right-of-way or roadway easement; slope maintenance easement for roadway cuts and fills may be required by the Planning and Development Director.
l. All excavated material shall be removed from lots and roadways or contained behind retaining walls or landscaped so that the slopes of any fill material will not be visible from any public street or private access ways. All cut slopes shall be chemically color treated to blend with the adjacent rocks or desert.
m. Panhandle, double frontage, and other unorthodox lots shall be permitted so long as it can be adequately demonstrated that this design will eliminate excessive cuts and fills and that no lot will be adversely affected by any other lot so arranged.
The panhandle portion of a hillside lot will not contribute to hillside grading area calculations if used solely for ingress/egress to a residence. The driveway within the panhandle, retaining walls required to build the driveway and a revegetated utility corridor directly adjacent to the driveway will be allowed and not included as disturbed area. Additional disturbance within the hillside panhandle portion of the lot will contribute to hillside grading area calculations.
n. Private access ways may be permitted to provide access to lots in lieu of the required street frontage. Each private access way serving one lot shall be a minimum of 20 feet wide with a minimum paved surface of 12 feet in width, and each private access way serving more than one lot shall have a minimum paved surface of 24 feet in width. Where needed, additional easements for draining or utilities shall be provided.
o. Disturbed areas outside of public right-of-way or private accessways, which are designated as slope easements for adjacent road construction, will not contribute to hillside grading area calculations if revegetated.
p. Maximum driveway grades shall not exceed 20 percent.
q. Building sites shall be located in accordance with recommendations of any required soils or geologic report and shall be free of any geological hazards or unsuitable soil conditions.
r. Development review standards shall be incorporated into the overall subdivision design as well as the individual lot design.
s. All excavated material shall be removed from the premises or maintained behind retaining walls or landscaped so that the slopes of any fill material will not be visible from any public street or private access way. All cut slopes shall be chemically color treated to blend with the adjacent rock or desert.
t. Retaining walls shall not be higher than six feet; any additional retaining walls shall be set back from the first wall a minimum of four feet horizontally. Retaining walls over four feet in height shall be set back an additional one foot horizontal for every one foot vertical. The area between stepped retaining walls shall be improved with hardscape or landscaping as approved by the Planning and Development Department.
4. Utilities. All utilities shall be installed underground in the streets and/or private access ways. Public water and sewer service shall be provided to each lot.
5. Grading standards for hillside lots and hillside PRD and PAD sites.
a. No clearing, grubbing or grading shall be permitted within the hillside development area as defined in Section 710.B of the Zoning Ordinance except in accordance with a site grading and drainage plan approved by the Planning and Development Department in accordance with the Grading and Drainage Ordinance.
b. Single-family hillside lots. Minimum 18,000 square feet to one acre.
(i) Total area of grading (including building area under roof). The total area of all site grading (including building area under roof), and other disturbed areas shall not exceed 35 percent of the hillside area of the lot or 20,000 square feet except that the Planning and Development Department landscape architect may approve an additional five percent gradable area, if the applicant revegetates all disturbed areas with desert vegetation.
(ii) Total area of grading for lots may be based on standards of an 18,000 square foot lot for lots subdivided prior to 1972; or any lots annexed into the City that contain less than 18,000 square feet.
c. Hillside single-family PRD and PAD sites multi-family residential and any other zoning district. The total area of grading (including building area under roof) shall not exceed 35 percent of the hillside area of the lot, parcel or PRD site.
SINGLE-FAMILY RESIDENTIAL LOTS MINIMUM 18,000 SQUARE FEET CONVENTIONAL DEVELOPMENT OPTION
SINGLE-FAMILY RESIDENTIAL PLANNED RESIDENTIAL DEVELOPMENT OPTION, PLANNED AREA DEVELOPMENT
ANY NON-RESIDENTIAL ZONING DISTRICT
Total grading: all site grading (including building area under roof)
Not to exceed 20,000 square feet
Not to exceed 20,000 square feet
*The department landscape architect may approve an additional five percent of grading subject to revegetation with desert vegetation and chemical treatment of all exposed cut and fill scars to blend with natural terrain. The area between stepped retaining walls shall be included in gradable area calculations as follows:
1) Revegetated with desert vegetation: Included in revegetation grading area maximum five percent.
2) If not revegetated with desert vegetation: Included in total site grading area, maximum 35 percent.
Grading for lots: subdivided prior to 1972 or annexed into the City which contain less than 18,000 square feet may be graded based on standards of an 18,000 square foot lot.
The maximum continuous edge of development adjacent to non-preserve hillside areas shall not exceed 500 feet. Each area shall be separated by an undisturbed common tract which is a minimum 50 feet in width.
d. Appeals. The City Manager’s Representative (CMR) shall hear all appeals of the Special Design Standards and Grading Standards for hillside lots and parcels and hillside PRD, PAD sites, and may approve grading in excess of 35 percent of the hillside area of a hillside lot or parcel or PRD, PAD site if:
There exists one or more of the following hardships not caused by the applicant:
(a) The lot was legally created, but does not contain sufficient area to comply with the minimum hillside lot size requirements of this chapter;
(b) The lot was disturbed or graded prior to 1972 or prior to annexation by the City;
(c) The lot complies with the minimum hillside lot requirements of this chapter, but due to the steepness of the slope, additional grading is required to accommodate a driveway or cut and fill areas necessary to provide a building site and minimal pool, yard areas;
(d) Additional grading in flat areas will permit preservation of unusual topographic features such as washes or rock outcroppings;
(e) The lot has no significant natural topographic features or significant vegetation;
(f) The purpose of the ordinance will not be served due to the detrimental impact of the character on surrounding properties.
(2) Hearings. The CMR shall hold a hearing on applications to exceed the grading standards at which the applicant and any interested parties have an opportunity to be heard.
(a) The property which is the subject of the hearing will be posted by the City for a period of 15 days prior to the hearing to notify interested parties of the impending hearing. It shall be the responsibility of the applicant to ensure that the posting remains in place for the entire 15-day period.
(b) At least 15 days prior to the hearing, the applicant will notify property owners’ neighborhood organizations registered with the Neighborhood Services Department surrounding the property which is the subject of the appeal to a distance of 300 feet of the impending hearing through a certified letter sent at the applicant’s expense. The form of letter shall be approved by the Planning and Development Department. Properties within 300 feet will be identified by the applicant. The applicant will obtain names and addresses of the owners of these properties from the Maricopa County Assessor’s Office and will notify these owners at the applicant’s expense by certified mail of the impending hearing. Before the appeal is processed, the applicant must provide to the Planning and Development Department the list of property owners and receipts from the certified letters sent to each of these owners.
(c) The CMR may approve a grading waiver subject to general or substantial conformance to a submitted plan. A CMR hearing is required for a major amendment to an approved grading plan. The determination of the need for a public hearing will be made by the Subdivision Committee of the Planning and Development Department.
(d) The CMR’s decision shall be final unless the applicant or any interested parties, within ten days after the decision is announced, requests in writing that the Development Advisory Board hold a hearing on the appeal, at which the applicant and any interested parties have an opportunity to be heard. Notice of any hearing held pursuant to this subsection shall be posted on the subject property at least 15 days prior to the hearing.
(3) Administrative approval. The CMR may consider administrative approval of a grading waiver without holding a public hearing if the following conditions are met:
(a) The Planning and Development Department recommends approval of the request.
(b) The applicant is in agreement with the Planning and Development Department recommendation and any proposed stipulations.
(c) The property has been posted for a period of 15 days prior to the administrative approval date. It shall be the responsibility of the applicant to ensure that the posting remains in place for the entire 15-day period.
(d) At least 15 days prior to the administrative approval date, the applicant will notify property owners’ neighborhood organizations registered with the Neighborhood Services Department surrounding the property which is the subject of the appeal to a distance of 300 feet of the impending approval date through a certified letter sent at the applicant’s expense. The form of letter shall be approved by the Planning and Development Department. Properties within 300 feet will be identified by the applicant through Maricopa County Assessor’s website resources. The applicant will notify these owners at the applicant’s expense by certified mail of the impending hearing.
(e) The administrative approval will become effective on the proposed approval date unless a grading waiver is provided in writing to the Planning and Development Department by close of business prior to the administrative approval date. The written form of letter requesting the grading waiver hearing shall be approved by the Planning and Development Department. If the Planning and Development Department is notified in writing as described, a grading waiver hearing will be conducted by the City Manager’s representative.
e. Validity. The approved grading waiver shall be valid for a period of 24 months and continues in effect beyond 24 months if a grading permit has been issued and has not expired.
f. Enforcement. Maintaining premises in violation of Hillside Regulations after annexation or after the effective date of the Hillside Ordinance provisions shall be grounds to prohibit the issuance of additional building permits until violations are corrected.
(1) Any lot which is graded after annexation or the effective date of the Hillside Ordinance without a valid grading permit or beyond areas shown on an approved hillside plan shall be restored to natural grade and revegetated with plant material to resemble and blend with:
(a) Surrounding undisturbed hillside areas; and/or
(b) Surrounding plant material in the immediate context area; and/or
(2) Receive appropriate plan approvals or grading waivers as approved by the Planning and Development Department or subsequent appeal.
g. Definitions. All definitions are from the Zoning Ordinance unless otherwise referenced. (Ord. No. G-3588, § 2; Ord. No. G-3732, § 1; Ord. No. G-3995, § 1, 1997; Ord. No. G-4176, §§ 6, 7, 1999; Ord. No. G-4554, § 1, 2003; Ord. No. G-5590, § 1, 2011; Ord. No. G-5707, 2012)
Cross reference—Grading and drainage, ch. 32A.