A. Purpose. The purpose of this section is to encourage, and provide incentives for, innovative site planning of residential subdivision lots that are designed in harmony with the natural features and constraints of property. This section establishes subdivision development standards which allow a landowner to achieve full density under the existing zoning of the land, and which also provide substantial preservation of natural open space and natural and cultural resources.
The goal of conservation site planning is to protect conservation features such as designated peaks and ridges, riparian areas, native plants and plant communities, areas near public preserves, wildlife habitat areas, biological corridors, and sites of archaeological and cultural value. Conservation subdivisions promote the establishment of conservation natural areas and, where possible and practicable, support interconnected, continuous, and integrated open space systems within an area, particularly when located contiguous to public preserves.
B. Applicability. These standards may be used to develop subdivisions on land containing undeveloped indigenous habitat and conservation features identified by the property owner in a conservation subdivision plat through aerials and supporting documentation, and certified as containing undeveloped indigenous habitat by the planning official. Any dispute about applicability of these standards to a particular parcel of land shall be reviewed at a public hearing before the planning and zoning commission. Except as noted in this section all other requirements of the Pima County Zoning Code shall apply.
C. Definitions. The following definitions apply to this section:
1. Conservation subdivision. A residential subdivision that is designed according to the procedures set forth in this section. A conservation subdivision allows a property to be developed to the full residential density permitted under the existing zoning classification, while also providing for the permanent conservation of substantial amounts of environmentally and culturally valuable open space areas, such as designated peaks and ridges, riparian areas, native plants and plant communities, areas near public preserves, wildlife habitat areas, biological corridors, and sites of archaeological and cultural value.
2. Conservation natural areas. Those areas within a conservation subdivision that are permanently designated and deed restricted to natural open space use by a conservation easement or owned in fee.
3. Conservation easement. A nonpossessory interest of a holder in real property imposing limitations or affirmative obligations for conservation purposes.
4. Conservation purposes. Any of the following activities which yield a significant public benefit:
a. Protecting a relatively natural habitat of wildlife, plants, similar ecosystem, or conservation natural area.
b. Preserving open space, including natural open space and conservation natural area, if the preservation is either:
1) For the scenic preservation of the natural area.
2) Pursuant to a clearly delineated federal, state or county governmental conservation policy.
c. Protection of archaeological and cultural resources.
5. Designated homesite area. That portion of a lot not restricted by a conservation easement.
6. Disturbed, disturbance. Refers to a significant visible man-caused change to an undisturbed natural area, site or conservation feature such as the ground surface, geology, vegetation, riparian area, or nesting habitat; and wherein such change results in (a) the degradation of the undisturbed natural area, site or conservation feature and (b) a corresponding reduction in the resource value of the natural area, site or conservation feature. Intrusive activities which degrade undisturbed natural area, site or conservation features, and reduce resource value include dumping, burning, toxic spills, plant pruning and removal, planting invasive and/or high water usage plant material that endangers or threatens the survivability of existing or introduced native plants and low water use, drought tolerant plant material, man caused erosion, grading, grubbing, scarifying, storage, vehicular, motorized and wheeled activity, grazing, pasturing, farming, and other similar intrusive activities.
7. Holder. Either:
a. A governmental body empowered to hold an interest in real property under the laws of this state or the United States.
b. A homeowners association, nonprofit charitable corporation or trustee of a charitable trust, the purposes or powers of which include retaining or protecting the natural, scenic or open space values of real property, and assuring the preservation, maintenance, and management of real property, and protecting and enhancing the undisturbed character and quality of conservation natural areas.
8. Indigenous habitat. Undeveloped areas consisting of plant communities that grow naturally in and are native to Pima County.
9. Primary conservation features. Those parts of the site which contain primary resource value natural features such as:
a. Lakes, ponds, wetlands, floodway and erosion hazard setback areas;
b. Riparian areas, prominent hilltops, peaks or ridges, and prominent rock outcroppings extending from public preserves;
c. Riparian habitat corridors and riparian areas of hydroriparian, mesoriparian, and xeroriparian A, B, and C, and any segments of riparian areas that are hydroriparian and mesoriparian according to Riparian Habitat Regulations in Article X of the Pima County Floodplain and Erosion Hazard Management Ordinance;
d. prominent vegetative and geologic features of a site, including saguaros and ironwoods, mesquite bosques, prominent hilltops and prominent rock outcrops, and peaks or ridges;
e. habitat with plant species listed as Highly Safeguarded by the Arizona Native Plant Law;
f. areas of undisturbed native upland vegetative communities adjacent to primary riparian area; and
g. slopes of twenty-five percent (25%) or greater.
10. Private living area. That portion of a designated homesite occupied by buildings, walls, patios, vehicular parking and circulation areas, and connecting pedestrian walks.
11. Riparian area. A geographically delineated area with distinct resource values that is characterized by deep-rooted plant species that depend on having roots in the water table or its capillary zone and that occurs within or adjacent to a natural perennial or intermittent stream channel, or within or adjacent to a lake, pond or marsh bed maintained primarily by natural water sources, or in or adjacent to ephemeral stream channels. Riparian areas routinely include hydroriparian, mesoriparian, and xeroriparian A, B, and C, any segments of riparian areas that are hydroriparian and mesoriparian. Riparian habit area does not include artificially created stockponds, man-made storage reservoirs constructed primarily for conservation or regulatory storage, municipal and industrial ponds or man-made water transportation, distribution, off-stream storage and collection systems.
12. Restored, restoration, mitigation. The process of repairing a previously disturbed, damaged, or graded site area or site feature and replicating its previously undisturbed, undamaged, or ungraded condition of vegetation, plant communities, geologic structures, grade, drainages, and riparian area that historically existed on site or in the neighborhood. Restoration of previously disturbed or graded areas will include revegetation, and may include corrective grading, natural and artificial rock, and top dressing.
13. Secondary conservation features. Those parts of a site which contain the secondary resource value natural features such as:
a. Segments of riparian area not connected to or extending from a public preserve;
b. Riparian areas not designated as primary conservation features;
c. Areas of undisturbed native upland vegetation communities;
d. Habitat with plant species listed as Salvage Restricted per the Arizona Native Plant Law;
e. Areas between fifteen percent (15%) and up to but not including twenty-five percent (25%) slopes;
f. One hundred year floodplain areas; and
g. Sites and features of archaeological and/or cultural value.
14. Third party right of enforcement. A right granted in a conservation easement to enforce any of its terms granted to a governmental body, nonprofit charitable corporation, charitable trust, or foundation, which, although eligible to be a holder, is not a holder.
15. Wildlife friendly fencing. Shall be a maximum 42? high fence using T-posts and 12-gauge wire as installed, maintained and further provided, and revised in conformance with the requirements and specifications of the Arizona Game and Fish Department for Standard Game Fence, or any subsequent revisions.
D. Permitted zones. This applies to subdivision development in the following zones: IR, RH, GR-1, SR, SR-2, SH, and CR-1, and specific plan development areas with land use designations that are comparable to IR, RH, GR-1, SR, SR-2, SH, or CR-1 zones.
E. Development standards.
1. Maximum density yield: Maximum density yield is obtained by dividing the minimum area per dwelling unit standard allowed under the zone of the property into the gross area of the subdivision site. SH shall use the same minimum area per dwelling unit as GR-1.
2. Minimum lot size:
a. GR-1, SH, and, CR-1: eighteen thousand (18,000) square feet, however, twenty percent (20%) of the lots may be smaller than eighteen thousand (18,000) square feet provided that the smaller lots are located on the interior of the project and provided that no lot is smaller than twelve thousand (12,000) square feet;
b. SR-2: thirty thousand (30,000) square feet;
c. IR, RH, SR: forty-three thousand five hundred and sixty (43,560) square feet;
d. All lots using a septic system shall meet all county requirements pertaining to lot size and septic use.
3. Minimum building setback:
a. Subdivision site setbacks for the entire subdivision are the same as the setbacks permitted in the zone for a single lot, but in no case shall a subdivision site setback be less than thirty feet (30');
b. Front yard setbacks of individual lots shall be a minimum of twenty feet (20');
c. Rear yard setbacks of individual lots shall be a minimum of ten feet (10');
d. Side yard setbacks along an internal subdivision street frontage and between adjoining subdivision lots shall be a minimum of ten feet (10');
e. The provisions of Section 18.07.070 (modification of setback requirements) apply to a conservation subdivision. For the purposes of this section, site setbacks and front yard setbacks in a conservation subdivision may also be reviewed for modification.
4. Domestic animals: the subdivision plat shall have covenants regulating the keeping of domestic animals as follows:
a. Domestic pets shall be confined to private living areas or accompanied on a leash outside private living areas by a resident or trainer, except as provided in the following subsection b. Domestic pets are domestic animals whose nature is consistent with the residential character of the neighborhood or the adjoining conservation natural area.
b. Fenced dog runs may be located outside private living areas within the designated homesite area;
c. Livestock may be kept in SR, RH, & IR Conservation Subdivisions and such livestock shall be confined in barns, sheds or fenced enclosures all within the designated home site areas.
d. No wild animal, as defined in Chapter 6.04 Pima County Code shall be kept.
e. The number of domestic animals on a lot shall be consistent with the residential character of the neighborhood.
5. Fencing and walls are permitted as follows:
a. Fencing and walls in private living areas on individual lots;
b. Wildlife friendly fencing that is required to protect cultural and natural resources from negative impacts such as human trespass and adjacent grazing areas;
c. Fencing and walls for livestock enclosures in the designated homesite area.
6. Driveway widths shall be limited to twelve feet (12') with a maximum six-foot (6') graded area on each side of the driveway where required to accommodate sloping site conditions.
F. Conservation natural area standards. The planning official, or the planning official's designated representative qualified in such matters, shall review the subdivision's conservation natural area to ensure that it protects natural area connections and important habitat features. A conservation subdivision shall comply with the following standards:
1. Minimum conservation natural area designation:
a. A minimum of fifty percent (50%) of the area of the subdivision site after deducting major streets and scenic routes rights-of-way dedications shall be set aside and restricted to conservation natural areas. When the best available scientific information confirmed by the planning official, or his designated representative qualified in such matters, indicates that a higher percentage of conservation natural area or conservation easement is required, such additional area shall be provided to the maximum extent practicable. Primary conservation features shall be the highest priority feature to be included in conservation natural areas within the subdivision. After all primary conservation features are designated as conservation natural area, any remaining required percentage of natural area shall include secondary conservation features.
b. On lots containing two (2) or more acres, or in low density subdivisions with a density less than one (1) dwelling unit per two (2) acres, up to thirty percent of the conservation natural areas required in the preceding subsection 1.a. may be located within individual subdivision lots, provided they are restricted to natural area use through recorded conservation easements.
c. No graded or disturbed area shall be part of the conservation natural area calculation.
2. Grading and conservation natural areas.
a. Grading of a subdivision site is permitted only for roadways, utilities and within the approved development areas.
b. The maximum grading area on lots smaller than one (1) acre shall be twenty thousand (20,000) square feet plus the area of a single lane twelve foot (12') wide driveway that extends from the lot property line to the garage or carport.
c. The maximum grading area on lots one (1) acre or larger shall be thirty thousand (30,000) square feet plus the area of a single lane twelve foot (12') wide driveway that extends from the lot property line to the garage or carport.
d. To the fullest extent possible, improvements shall be sited to minimize disturbance in conservation natural areas and of the primary and secondary conservation features within them.
e. The design of the development area shall be done so the grading has the least impact on the primary conservation features.
f. Mitigation of disturbed conservation features shall be done in accordance with the purpose of this section, as approved by the planning official, or his designated representative qualified in such matters.
g. Mitigated areas are not counted or included in the calculation of the percent of conservation natural area required for a subdivision site.
h. Washes. Within washes that are primary or secondary conservation features, only that grading for roadways and utilities that is necessary to provide access to approved development areas is permitted in accordance with Chapter 16.54 (Riparian Habitat Ordinance) of this code. Wash disturbance shall be minimized and all utilities shall be installed within roadway easements, except that where a roadway easement is not a practicable location for the utility as confirmed by the planning official, or his designated representative qualified in such matters, then the utility may cross a wash using the least intrusive construction methodology and subject to mitigation and revegetation of the wash disturbance. Wash areas so disturbed and subsequently mitigated shall not be included as part of any open space or natural area requirement.
i. Native plants. To the fullest extent possible, buildings and other improvements shall be sited so as not to disturb primary and secondary conservation features such as saguaros and ironwood trees. Transplantation of existing indigenous plant material shall be within the subdivision. Transplanting or mitigation shall be conducted as follows:
1) Mitigation including transplanting and revegetation for roadways, utilities, and siting of dwellings and private living areas must be done in accordance with Chapter 18.72 (Native Plant Preservation Standards).
2) Grading and disturbed areas in designated homesite areas located outside private living areas, fenced dog runs, and livestock enclosures shall be revegetated with plant material indigenous to the site or subdivision that replicates the understory, midstory, and canopy of adjoining conservation natural areas; except that native, drought-tolerant, low-water use plants (including trees shrubs, cacti, ground cover, grasses and seed mixes) approved by the planning official, or his designated representative qualified in such matters, may also be used.
j. Except as otherwise provided in subparagraph i. above, revegetation of graded or disturbed areas shall be with indigenous trees, shrubs, and ground cover to simulate understory, midstory, and canopy of adjoining natural areas.
k. Site development shall include reduction of runoff by means of stormwater harvesting, erosion control through benign grade stabilization, and careful siting of improvements to minimize negative impacts in conformance with accepted local green infrastructure and low impact development practices and concepts.
3. To assure the most beneficial natural area design, conservation natural areas shall provide, where possible and practicable, connections to public preserves, undisturbed riparian areas, and natural areas on adjoining properties, and protection of undeveloped indigenous habitat.
4. Long thin strips of natural areas shall be avoided unless the feature is linear, such as a wash or the configuration is necessary to connect with other washes or trails. The conservation natural areas shall generally abut existing or potential natural areas on adjacent parcels. Where possible, such subdivision conservation natural areas shall be designed as part of a larger contiguous and integrated open space system of undeveloped indigenous habitat.
G. Infrastructure standards.
1. Conservation subdivisions may use the more flexible street development standards established in the standards and policies of the department of transportation and flood control district for conservation subdivisions and shall emphasize protection of wildlife corridors and minimization of traffic killings of wildlife.
2. Notwithstanding the restriction on the length of cul de sacs contained in Section 18.69.040.A2.l (Subdivision Standards), there is no restriction on cul de sac length in a conservation subdivision. However, no cul-de-sac may serve more than one hundred dwellings or any use that would generate one thousand or more average daily vehicle trips.
3. Existing ingress and egress easements adjacent to or within the subdivision boundaries and which serve lots within the subdivision shall be designated as common area. Existing ingress and egress easements within the subdivision that do not serve lots within the subdivision but only serve parcels outside the subdivision may remain as part of a subdivision lot. Existing ingress and egress easements connected to subdivision boundaries may serve subdivision lots.
H. Site planning procedure.
1. Pre-application meeting: Prior to the submittal of a tentative subdivision plat, the applicant shall prepare a tentative plat sketch proposal which shows the proposed conservation natural areas, the lot pattern, streets, and trail linkages of development areas and to meet with the planning official, or the planning official's designated representative, to discuss how the conservation subdivision standards can be applied to the subject property.
2. Tentative plat. The tentative plat shall be prepared in compliance with the following design process:
a. Determine the maximum density yield.
b. Identify conservation natural areas. All potential conservation natural areas are to be identified. Lands shall be considered for designation as conservation natural areas in the following order:
1) Areas which qualify as primary conservation features;
2) Areas which qualify as secondary conservation features;
3) Areas the property owner may want to preserve.
c. Identify development areas. The areas that are not identified as conservation natural areas and are available for development.
d. Locate building sites. The approximate sites of individual buildings are tentatively located.
e. Align streets. Streets shall be laid out in a way that avoids, or at least minimizes, adverse impacts on conservation natural areas to the greatest extent practicable. Wash crossings and streets traversing existing slopes greater than fifteen percent (15%) are discouraged.
f. Draw the lot lines. The lot lines should, where possible, be located approximately midway between house locations and may include L-shaped lots which meet county standards.
3. County evaluation of tentative conservation subdivision plat. Development services shall review the plat to ensure that the design is appropriate to the site's natural, historic, and cultural features and the purposes of this section. Diversity and originality in lot layout are encouraged to achieve the best possible relationship between development and conservation natural areas. To the greatest extent possible and practicable, the layout of a tentative plat shall meet the following standards:
a. Protects and conserves riparian areas, slopes greater than fifteen percent (15%), and designated peaks and ridges from clearing, grading, filling, or construction except as may be approved for essential infrastructure;
b. Creates buffer areas to minimize conflicts between residential uses, public preserves, and wildlife habitat;
c. Locates development on the least environmentally sensitive areas of the site with the least intrusion into primary and secondary conservation features and is least disruptive to connections with public preserves and surrounding undeveloped indigenous habitat;
d. Protects wildlife habitat areas of species listed as endangered, threatened, or of special concern by the U. S. Fish and Wildlife Services, Arizona Game and Fish Department, and the adopted Sonoran Desert Conservation Plan.
e. Minimizes development impacts on ironwoods, saguaros and their understory, and large clusters of sensitive plant groups protected by the native plant preservation standards (Chapter. 18.72);
f. Avoids siting dwellings on prominent hilltops or ridges by taking advantage of lower topographic forms;
g. Designs around and preserve sites of historic, archeological, or cultural value and their environs insofar as needed to safeguard the character and integrity of the feature;
h. Improves public safety and protects the character of scenic routes by avoiding lot development which directly accesses onto scenic routes that are also major routes;
i. Where trails are provided, they shall be designed as a pedestrian circulation path system to ensure that pedestrians can walk safely and easily on the site, between properties and activities or special features within the neighborhood open space system;
j. Provides natural areas that are contiguous and whose configuration minimizes fragmentation of natural areas within the development;
k. Incorporates a water harvesting plan.
l. Revegetation shall be indigenous trees, shrubs, and ground cover to simulate when practicable understory, midstory, and canopy of adjoining natural areas.
I. Lot development. Lots thirty-six thousand (36,000) square feet or greater with grading areas greater than fourteen thousand (14,000) square feet shall, at the time the lot is developed, incorporate a thirty percent natural area set aside into the lot design, if not already delineated by the plat. The natural area set aside should, when possible, provide connections to adjoining common or individual lot conservation natural areas, and building area footprints should be minimized. To the maximum extent possible, open space areas adjacent to streets that are located on individual lots shall be left natural.
J. Conservation natural areas ownership and maintenance. Conservation natural areas shall be restricted to natural open space in perpetuity. The conservation natural areas shall remain undivided. Conservation natural areas located outside of individual residential lots shall be owned and managed by either a homeowners' association, the county, or a recognized land trust or conservancy.
1. Conservation natural areas located outside of individual lots shall be preserved by one of the following methods:
a. Dedication. Conservation natural areas may be dedicated to the county, either in fee simple or as a conservation easement, by a form of instrument approved by the county. The county may, but is not required, to accept conservation natural areas.
b. Transfer to a private conservation organization, land trust, or conservancy. Conservation natural areas may be transferred either in fee or by easement to a private nonprofit organization, among whose purposes it is to conserve conservation natural areas and/or natural resources provided that:
1) The organization is acceptable to the county;
2) The organization is a bona fide conservation organization with perpetual existence;
3) The conveyance contains appropriate provisions for the transfer of the conservation natural area to the county, an appropriate homeowners association, or another private nonprofit organization acceptable to the county, if the original organization becomes unwilling or unable to continue carrying out its function; and
4) A maintenance agreement approved by the county is entered into by the owner of the subdivision site and the non profit conservation organization.
c. Transfer to a homeowners' association and maintenance standards. If the conservation natural areas are to be owned and maintained by the homeowners' association of the subdivision, the subdivider shall record covenants, conditions and restrictions including maintenance and preservation standards, running with the land, providing for the creation of a homeowners' association. The covenants shall contain the following provisions:
1) A clause assuring that Pima County is not responsible for maintenance or liability of the common natural areas but that Pima County may enforce the maintenance and preservation standards;
2) A clause stating the common areas designated natural area on the subdivision plat shall be restricted to natural areas in perpetuity and maintained by the homeowners association and a requirement that the county is a third party beneficiary with a third party right of enforcement to such clause, and that the clause cannot be amended or repealed without the written consent of the county.
3) The developer shall present to the development services department a plan for the transfer of control of all common natural areas to the homeowners association;
2. Conservation natural areas on individual lots shall be preserved as recorded conservation easements. The conservation easement shall include a statement that all area within the conservation easement shall be preserved as natural open space and shall not be graded or disturbed except that previously graded or disturbed areas within the conservation easement shall be restored, and revegetated in conformance with the provisions of the following subsection 3.
3. Maintenance of conservation natural areas on individual lots:
a. Conservation natural areas shall be preserved as natural open space and shall not be graded or disturbed, except for restoration and the mitigation of previously disturbed area.
b. Existing grading or disturbance within the conservation natural area shall be restored, and mitigated subject to the following:
1) The existing grading and disturbance occurred two (2) years or more before the effective date of the ordinance that establishes this provision, and
2) The existing grading and disturbance was not created during the current owner's ownership of the lot, parcel, or project site.
3) An application for a building or grading permit on a lot, parcel, or project site that meets the preceding conditions in subparagraphs 1) and 2) shall be accompanied by a mitigation and revegetation plan which mitigates the existing grading and disturbance in conformance with the revegetation requirements of Section 18.61.100.F.2.i.2)
4) If the existing grading and disturbance does not meet one (1) or both of the preceding conditions in subparagraphs 1) and 2), then supplemental mitigation requirements may be established by the planning official or a hearing officer.
(Ord. 2015-7 § 3, 2015; Ord. 2001-22 § 1, 2001; Ord. 2000-66 § 1, 2000)