A. Purpose And Intent: This section is adopted to promote public safety and the general public welfare; to protect property against loss from erosion, earth movement and flooding; to maintain a superior community environment; to provide for the continued orderly growth of the City; and to ensure the maximum preservation of the natural scenic character of major portions of the City by protecting against detrimental impacts to neighboring properties due to large changes in the natural grade and topography; to prevent large unsightly exposed surfaces of retaining walls that attract graffiti, generate large amounts of heat and runoff, and create significant incompatibility between the grades of neighboring properties; and to encourage preservation of the natural grade and topography, and to encourage adaptation of new development to existing grades; to establish minimum standards and requirements relating to land grading, excavations, and fills, and procedures by which these standards and requirements may be enforced. It is intended that this section be administered with the foregoing purposes in mind and specifically in an attempt to:
1. Ensure that the development of each site occurs in a manner harmonious with adjacent lands so as to minimize problems of drainage, erosion, earth movement and similar hazards.
2. Ensure the public lands and places, watercourses, streets, and all other lands in the City are protected from erosion, earth movement or drainage hazards.
3. Ensure that the planning, design and construction of all development will be done in a manner which provides maximum safety and human enjoyment and except where specifically intended otherwise, makes such construction as unobtrusive in the natural terrain as possible.
4. Ensure the maximum retention of natural vegetation to aid in protection against erosion, earth movement and other hazards and to aid in preservation of the natural scenic qualities of the community.
5. Provide for a recordable instrument of acknowledgement executable by the property owner accepting maintenance of grading and/or surface water retention improvements. (Ord. 2018-16, 10-11-2018)
B. Permit Required:
1. Grading permits are required for work on new developments, construction projects, rivers, washes, streams, floodplains, detention basins, dams, ditches, drainage culverts, slopes in excess of fifteen percent (15%), rock pits, roads, utilities, well drilling. Permitted and non-permitted work shall not encroach nor impact on adjacent properties. Sanitary (garbage) landfills and hazardous material depositories shall not be allowed. A grading permit may be combined with a building permit.
2. For work requiring a permit, plans and specifications shall be completed by a registered professional engineer and/or a registered professional landscape architect or registered professional arborist.
3. Retaining walls in excess of four feet (4') require a permit. Plans shall be submitted in accordance with subsection F of this section. (Ord. 2019-04, 2-28-2019)
4. Approved permits shall be issued upon execution of an acknowledgement of "Site Grading Management Agreement" kept on file with the City, which shall be recorded against the property.
C. Responsibility: Failure of the City officials to observe or recognize hazardous or unsightly conditions, or to recommend denial of the conditional use permit, or of the Planning Commission to deny said permit shall not relieve the permittee from responsibility for the condition or damages resulting therefrom.
D. Retention Of Plans: Plans, specifications and reports for all conditional use permit applications submitted to the City for approval shall be retained by the City for a minimum period of two (2) years.
E. Inspections:
1. The Community Development Director and building official, with assistance from the City Engineer, shall make the inspections of all projects under "permit". Where it is found that conditions substantially differ from those stated or shown in the conditional use permit application, the City may stop further work until and unless approval is obtained for a revised grading plan conforming to the existing conditions.
2. Plans for grading work shall be maintained at the site during the progress of the grading. Until the final inspection is made, the building permit shall be prominently displayed near the front property line of the property involved so as to be visible from the street on which the property fronts.
3. In order to obtain inspections, the permittee shall notify the City twenty four (24) hours before said inspection is to be made.
4. Inspections shall be made:
a. Before commencement of grading operations and after required construction stakes have been set; and
b. When all rough grading has been completed; and
c. When all work, including installation of all drainage and other structures and required planting, has been completed.
F. Standards And Specific Requirements For Grading And Retaining Wall Systems:
1. All grading, fill work and excavation shall comply with the requirements set forth in this chapter in addition to other requirements of this Code.
2. All grading and excavation in or adjacent to residential neighborhoods shall comply with the City's noise ordinance.
3. All graded or disturbed surfaces of excavations, and all equipment materials and roadways on the site shall be dampened or suitably treated, managed, or contained to prevent the deposit of dust on neighboring properties; all materials transported to or from the site shall be so contained during transportation as to prevent spillage on streets or other property outside of the site.
4. Maximum unretained or exposed slope of a permanent cut and fill area shall be thirty percent (30%). The City Engineer may require the percent of slope of a cut or fill to be reduced if it is found that the cut or fill is subject to unusual or excessive erosion, or if other conditions make such requirements necessary for stability.
5. All fill, except in publicly approved refuse disposal or other landfill operations, shall be earth, rock, or other inert materials free from organic material and free of metal, and except that topsoil spread on cut and fill surfaces may incorporate humus for desirable moisture retention and plant growth properties.
6. Adequate provisions shall be made to prevent any surface waters from damaging the cut face of an excavation or any portion of a fill. All drainage ways and structures shall carry surface waters without producing erosion to the nearest practical street, storm drain or natural watercourse acceptable to the City Engineer as a safe place to deposit and receive such waters. The City Engineer may require such drainage structures to be constructed or installed as necessary to prevent erosion damage or to prevent saturation of the fill or material behind cut slopes.
7. Exposed or finished cuts or slopes of any fill or excavation shall be smoothly graded to a maximum slope of thirty percent (30%). All exposed slopes of any cut or fill shall be protected from erosion or sloughing by approved plantings or graded terracing, crib walls or walls and planting, terracing, or combination thereof.
8. Artificial Grade Alterations:
a. Grading intended to raise and level the developable area of a site to support driveways, patios or other structures shall be limited to a maximum of two feet (2') above the averaged grade elevations of the abutting properties.
b. Maximum depth of backfilled grades within four feet (4') of a property line shall be two feet (2') and finished at a 1:1 slope.
9. Retaining walls or retaining wall systems within a required yard setback require review and approval by the City Engineer and shall be located, designed and constructed as follows.
For the purposes of this section a retaining wall or grade retaining system may include, but is not limited to, gravity, crib, gabion, cantilever, rip-rap boulder or anchored systems designed to retain lateral soil loads.
a. Prohibited Locations: No retaining wall or retaining wall system shall be constructed on a property line, or within a recorded easement(s) as shown in figure 13.76.1.
b. Retaining walls holding the cut soil of the natural slope shall designed and constructed as shown in figure 13.76.1.
(1) Minimum one foot (1') setback to any footing of the retaining wall.
(2) The maximum height of any retaining wall shall not exceed six feet (6') below the natural grade.
(3) The area to be cut and retained shall not to exceed twenty percent (20%) of the required setback area.
(4) Retaining walls located in a required front yard or required corner side-yard setback, along a public or private right-of-way, shall be set back a minimum of four feet (4') from the right-of-way line.
(5) Each subsequent retaining wall must be accompanied by a horizontal landscaped offset measuring no less than the height of the retaining wall.
(6) Guard rails, barriers, or other screening type structures used in conjunction with a retaining wall shall not exceed forty two inches (42") above the top of the wall.
c. Retaining walls or retaining wall systems holding artificially backfilled grades within a required setback shall be designed and constructed as shown in figure 13.76.1, Retaining Backfilled Grades.
(1) Minimum of an eight foot (8') setback required for any retaining wall system.
(2) Each subsequent retaining wall must be accompanied by an additional, horizontal landscaped offset of eight feet (8').
(3) The maximum height of any retaining wall shall not exceed four feet (4') measured from the natural grade. Height shall be stepped horizontally every ten feet (10') to accommodate the natural topography.
(4) Guard rails, barriers, or other screening type structures used in conjunction with a retaining wall shall not exceed forty two inches (42") above the top of the wall.
d. Retaining walls or retaining wall systems adjacent a natural waterway or canal shall adhere to the provisions set forth in section 13.76.400 of this title.
10. Retaining walls associated with a residential or nonresidential, planned development use may be approved by the Planning Commission upon recommendation of the Technical Review Committee according to procedures set forth in section 13.78 of this title.
11. Any pipe trench or other trenching or excavation made in any slope of any excavation or filled site shall be backfilled and compacted to the level of the surrounding grades.
12. Unless otherwise directed by the City Engineer, all fills governed by this Code intended to support buildings, structures, or where otherwise required to be compacted for stability, shall be compacted, inspected and tested in accordance with the following provisions:
a. The natural ground surface shall be prepared by removal of topsoil and vegetation and, if necessary, shall be graded to a series of terraces;
b. The fill shall be spread in a series of layers, each not exceeding six inches (6") in thickness, and shall be compacted by "sheepsfoot" roller compactor (after each layer is spread) or other method acceptable to the City Engineer;
c. The moisture content of the fill material shall be controlled at the time of spreading and compaction to obtain required maximum density;
d. The fill material after compaction shall have an average dry density of not less than ninety five percent (95%) of maximum dry density and a minimum of ninety percent (90%) in all portions of the fill requiring compaction as determined by the AASHO soil compaction test method T180-57, or other testing method acceptable to the City Engineer;
e. A written report of the compaction, showing location and depth of test holes, materials used, moisture conditions, recommended soil bearing pressures, and relative density obtained from all tests, prepared by a civil engineer or soils engineer licensed by the State of Utah, shall be submitted to the City Engineer; and
f. The Community Development Director and/or the City Engineer may require additional tests or information if, in his opinion, the conditions or materials are such that additional information is necessary, and may modify or delete any of the above listed requirements that in his opinion are unnecessary to further the purpose of this Code.
13. All cut and fill surfaces created by grading except for firebreak purposes shall be seeded with a ground cover that is compatible with the natural ground covers in the City. Topsoil is to be stockpiled during rough grading and used on cut and fill slopes. When slopes too steep to support continuous ground cover have been permitted and in lieu thereof niches and ledges provided for planting, such slopes need not be planted with a continuous ground cover, but may instead be screened with vines and plantings. Cuts and fills along public roads may be required to be landscaped so as to blend into the natural surroundings. All plant materials must be approved by the Community Development Director prior to issuance of a conditional use permit.
14. Filling of the ground for agricultural or fire protection purposes shall be accomplished with such practices as will prevent erosion and damage to natural drainage channels. (Ord. 2018-16, 10-11-2018; amd. Ord. 2020-12, 7-16-2020))
G. Final Inspection:
1. If upon final inspection of any grading it is found that the work authorized by the conditional use permit has been satisfactorily completed in accordance with the requirements of this Code and any other requirements imposed, the Community Development Director shall issue a certificate of compliance.
2. The Planning Commission shall have the power to revoke any conditional use permit whenever it is found that the work covered by the certificate has been materially extended or altered without prior approval, or that any planting, retaining walls, cribbing, drainage structures, or other protective devices as shown on the approved plans and specifications submitted with the application for a permit have not been maintained in good order and repair.
3. Before such revocation, the Community Development Director shall first give fifteen (15) calendar days' written notice to the owner of the property involved, specifying the defective condition and stating that unless such defective condition is remedied satisfactorily, the conditional use permit may be revoked. If the defective condition is remedied to the satisfaction of the community development director, the certificate shall not be revoked.
H. Special Precautions:
1. Special precautions shall be taken to preserve life, property values, stable soils conditions and aesthetics, including, but not limited to, the following:
a. Requiring a level exposed slope, construction of additional drainage facilities, berms, terracing, compaction, or cribbing, installation of plant materials for erosion control, and reports of a registered soils engineer and/or engineering geologist whose recommendation may be made a requirement for further mitigation of unstable conditions. (Ord. 2012-15, 9-20-2012)
b. Where it appears that storm runoff damage may result from work performed hereunder, such work may be stopped and the permittee required to take such measures as may be necessary to protect adjacent property or the public safety. On large operations or where unusual site conditions prevail, the community development director may specify the time at which grading may proceed and the time of completion or may require that the operation be conducted in specific stages so as to ensure completion of protective measures or devices prior to the advent of seasonal rains. (Ord. 2015-02, 2-5-2015)
I. Excavations:
1. All excavations shall be limited as follows:
a. No cut slope shall exceed a vertical height of fifty feet (50') unless horizontal benches with a minimum width of twenty feet (20') are installed at each fifty feet (50') of vertical height.
b. No excavation shall be made with a cut face steeper in slope than two horizontal to one vertical (2:1) unless otherwise approved by the community development director based on the recommendation of a professionally prepared soils report and/or after supporting data supplied by the applicant. In no case shall slopes be cut steeper than the bedding planes, fault or joint in any formation where the cut slope will lie on the dip side of the strike line of the fracture, bedding plane, fault or joint. No slopes shall be cut in an existing landslide, mudflow, or other form of naturally unstable slope except as recommended by a qualified geological engineer. Where the excavation is exposed straight above the top of the cut that will permit the entry of water along bedding planes, this area shall be sealed with a compacted soil blanket having a minimum thickness of two feet (2'). The soil for this blanket shall be relatively impervious and must be approved for such use by the soils engineering geologist. If the material of the slope is of such composition and character as to be unstable under the anticipated maximum moisture content, the slope angle shall be reduced to a stable value.
2. No excavation for construction of new utility lines shall be made in paved public streets within three (3) years after paving. During said three (3) year period, utility excavations may be authorized by the city for emergency reasons and when delaying such excavation would cause undue hardship provided that pavement repair and mitigation measures acceptable to the city engineer are implemented.
J. Fills:
1. All fills shall be limited as follows:
a. No fill slope shall exceed a vertical height of fifty feet (50') unless horizontal benches with a minimum width of twenty feet (20') are installed at each fifty feet (50') of vertical height.
b. No fill shall be made which creates an exposed surface steeper in slope than two horizontal to one vertical (2:1) unless otherwise approved by the community development director based on the recommendations of a professionally prepared soils report and/or other supporting data provided by the applicant.
K. Prohibited Activities:
1. The provisions of this chapter shall not be construed as permitting the removal of topsoil solely for resale, or of permitting quarrying of any site within the limits of the city.
2. This chapter shall also not be construed as authorizing any person to maintain a private or public nuisance upon his or her property, and compliance with the provisions of this chapter shall not be a defense in any action to abate such nuisance.
L. Remediation: In addition to enforcement provisions pursuant to chapter 13.94 of this title, violations of this section shall be subject to mandatory remediation of the site as specified by the community development director with technical assistance from the city engineer. (Ord. 2012-15, 9-20-2012)