The purpose of this section is to provide for the public health, safety, and general welfare and to protect and preserve the aesthetics of the natural desert environment through regulation of all types of excavation and earthwork on private and/or public land. It complements the applicable provisions of the Hillside Development Zone and the floodplain management ordinance and does not authorize any grading activity prohibited by any town ordinance.
The grading regulations contained in this ordinance are designed to:
1. Regulate the development of potentially hazardous terrain; and
3. Enhance the quality and value of new development; and
Further, the intent of this section is to assure that the design and implementation of all grading projects shall:
2. Blend with the natural contours of the land; and
3. Restrict the areas of disturbance and volume of material displaced to the minimum amount necessary to implement the planned development; and
5. Employ measures that:
d. Ensure that proposed development activity is designed and implemented to avoid adverse impacts and appropriate restorative measures; and
The design, implementation, and mitigation of grading regulated by this section shall be reviewed to ensure full compliance with the regulations, requirements and specific standards set forth herein, prior to the issuance of any grading permit type as defined in Section 22.10.B. This section shall apply to all grading operations for which applications were received subsequent to its adoption date (August 19, 1998), unless exempted by Section 22.10.A.2.
C. General Grading Requirements
1. Cut and Fill Limitations
a. The maximum depth of a cut or fill shall not exceed six (6) feet measured vertically from the existing grade to the finished elevation. The depth of a cut or fill slope may be increased to eight (8) feet when terracing is utilized in conformance with Illustration 27.9 - 3. The terraces shall be landscaped to the satisfaction of the Town. For any construction, the height of exposed, constructed slopes shall not exceed twelve (12) feet in vertical dimension.
Should a PAD (planned area development), existing at the time of adoption of the ordinance codified in this section, have conflicting cut and fill limitations, the PAD limitations shall govern grading operations within the PAD area.
b. Cut or fill slopes three to one (3:1) (horizontal: vertical) or less steep shall be revegetated. At the Town’s discretion, the Town may retain sufficient funds from the restoration or landscape assurance to ensure revegetation of slopes again, should the initial revegetation efforts fail to become established to the satisfaction of the Town.
c. Cut or fill slopes two to one (2:1) or less steep (but steeper than three to one (3:1)) shall be rock riprapped with filter fabric installed beneath the rock. Filter fabrics used shall meet specifications found in the latest edition of the “Pima County - City of Tucson Standard Specifications for Public Improvements.”
g. Any structure used to retain slopes shall be designed to blend with the surrounding natural colors of the native rock and soils of the site. The surface shall be rough textured with heavy shadow patterns, which may be achieved by color-treated or veneered surfaces (or other methods approved by the Town).
2. Site Revegetation and Stabilization
a. All graded areas, except those to be used for agriculture or livestock purposes, shall be revegetated, stabilized, and/or constructed prior to the expiration of the grading permit. Should the graded area not be revegetated and/or stabilized per approved grading plans or permit conditions at the time of expiration, the applicant shall have sixty (60) days from the date of permit expiration to revegetate and/or stabilize per approved plans and permit conditions. If after the sixty (60) day period, the applicant has not revegetated and/or stabilized graded areas, the applicant is in violation of this section. The Town may use the posted restoration assurance to restore the native vegetative community or complete the revegetation and stabilization per the approved grading plan.
b. The applicant shall provide the Town with an assurance in a form approved by the Town (see Section 26.6) equal to one hundred twenty (120) percent of the monetary amount necessary to hydroseed and revegetate cut/fill slopes or graded areas. Said assurance shall be posted prior to any site disturbance. The assurance shall be held until such time as the grading operation, infrastructure installation, building construction is completed to the satisfaction of the Town, or until such time as the project is deemed abandoned. If, after twelve (12) months from the date of commencement of work, revegetation efforts fail to establish growth to the satisfaction of the Town, the Town may use the assurances to revegetate or apply other erosion control methods to cut/fill slopes or the graded area.
All driveways shall be paved with a durable asphalt, concrete, brick, aggregate, or other surface that will maintain a dust free condition.
4. Slope Setbacks
a. Top of cut slope: The top of cut slopes shall be made not nearer to a site boundary line than one-fifth (1/5) of the vertical height of cut, with a minimum of two (2) feet, unless otherwise approved by the Town Engineer and the Planning and Zoning Administrator and upon written consent from the adjacent property owner. The setback may need to be increased for any required interceptor drains.
b. Toe of fill slope: The toe of fill slope shall be made not nearer to the site boundary line than one-half (1/2) the height of the slope, with a minimum of two (2) feet, unless otherwise approved by the Town Engineer and the Planning and Zoning Administrator and upon written consent from the adjacent property owner.
c. Building: Buildings shall be set back from the toe and top of slopes in accordance with the building codes (minimum five (5) feet, see Figure 27.9 – 1) and the approved soils report. In addition, the building setbacks of the applicable zoning district shall apply.
i. Easements are not required, or
ii. Retaining walls are used.
5. Restriction of Slope Development
a. For the purposes of this section, a regulated slope is one that has a minimum vertical difference of six (6) feet from its toe to top edge, and the regulated sloped area extends for a distance greater than thirty (30) feet in any horizontal direction.
b. New subdivisions shall not create lots where access to any individual lot requires crossing a naturally occurring slope that is twenty-five percent (25%) or steeper, nor shall new subdivisions be created where the actual building area for homes or buildings would require grading activity on slopes of twenty-five percent (25%) or steeper.
c. The design for new subdivisions shall be created to avoid construction on naturally occurring slopes fifteen percent (15%) or greater. On parcels or lots with fifteen percent (15%) or steeper slopes, any grading on said slopes shall be consistent with restrictions in the Hillside Development Zone, Section 27.10.
6. Protective Cover and Dust Control
Cleared or graded land shall not be left at any time without dust control nor shall be left uncovered for more than sixty (60) days without temporary or permanent protective cover of the entire cleared or graded area as determined by the Town Engineer.
7. Erosion Control Systems
a. Permanent Systems
iv. The shoulders of a paved public or private roadway shall be protected against erosion wherever curbing or constructed spillways are not provided.
v. Surface drainage:
b) Drainage control shall be provided to keep drainage away from foundations;
d) Subsurface drainage: Should subsurface drainage be encountered or expected by the soils engineer or the Town, then appropriate measures shall be employed to ensure stability and protection of affected properties from ground water seepage. Methods used to minimize impact by subsurface drainage/seepage shall be approved by the Town prior to installation.
b. Interim Systems: Plans for interim erosion control systems shall be submitted with all grading permit applications and shall be approved by the Town. Erosion control measures shall be implemented and properly maintained to prevent erosion of slopes, and cleared, brushed, grubbed or graded areas. Stabilization devices to prevent erosion or sediment deposition on adjacent roads and off-site property shall be required. The applicant shall be responsible for the control of dust emissions and shall use appropriate dust control measures. Applicants who are required to submit a U.S.E.P.A. Notice of Intent (NOI) for coverage under the National Pollutant Discharge Elimination System (NPDES) for their project shall provide a copy of the NOI and the Storm Water Pollution Prevention Plan (SWPPP) to the Town prior to issuance of a grading permit.
8. Import and Export of Earth Material
a. Loading of earth material shall occur only within the time limits of subsection C.9 of this section, and dust emissions shall be controlled through appropriate dust control measures.
b. The transportation of earth material on or across public rights-of-way shall be done in a manner that minimizes blowing soil and other hazards.
9. Hours of Grading
a. Grading equipment operation within one-half (1/2) mile of an occupied residential structure shall only be conducted between 6:00 a.m. and sunset Monday through Friday. Grading equipment operation shall only be conducted between the hours of 8:00 a.m. and 5:00 p.m. on Saturdays and Sundays.
b. Equipment maintenance involving lights, motors, or generators, and occurring within six hundred (600) feet of an occupied residential structure, shall not be conducted after sunset, or before 6:00 a.m.
c. The Town may allow grading equipment operation or maintenance during other hours, if such operations are not detrimental to the health, safety, or welfare of the residents of surrounding properties.
d. Permitted hours of operation or maintenance may be shortened by written notice to the permittee, if the Town finds a substantial adverse effect on the health, safety, or welfare of the surrounding community.
10. Phased Grading
b. For all projects ten (10) acres or larger requiring site plans, a phased grading concept plan may be required with the final site plan submittal. This plan shall be reviewed and approved by the Town Engineer.
ii. Efficient installation of infrastructure,
iii. Minimal need for stockpiling earthen material for more than six (6) months,
11. Restriction of Vehicles
12. Additional Requirements
b. Public rights-of-way, sidewalks, and other improvements shall be maintained during grading in a neat and clean condition, free of loose soil, mud, construction debris, and trash. Any damaged areas shall be restored to original appearance at no cost to the Town of Oro Valley.
d. If applicable, archaeological exploration and mitigation work, as recommended by a qualified archaeologist (see Section 27.3.E.2), shall be performed prior to commencement of grading operations on the affected portion of the site. If, during the grading phase of construction, unexpected archaeological findings are encountered, said grading shall cease and the grading permit shall be temporarily suspended until the significance of said finding is determined and mitigation is provided by a qualified archaeologist. The analysis of any finds shall be provided to the Town prior to reactivation of the grading permit, granting occupancy permits or release of assurances. The expiration date of a reactivated grading permit may be extended for a period equal to the time of suspension necessary to complete archaeological work.
e. Adjoining property(ies) shall be protected in such a manner as to prevent damage to said property(ies). Protection from caving, settlement, and other similar occurrences shall be the responsibility of the permittee (see Section 22.10.D.2, Liability).