To further the health, safety, and welfare of the inhabitants of the City and developers of project within the City, development in areas of special consideration shall be undertaken in accordance with the requirements of this chapter to minimize danger to persons and property and to ensure development of lasting value.

(Ord. 2014-6, 5-1-2014; Ord. No. 2024-15, 11-21-2024)

A.

Report required.

1.

A geotechnical report shall be prepared by a state licensed professional engineer who is trained and experienced in the practice of geotechnical engineering whenever a proposed building permit in an area that has not been reviewed under this chapter or a development project is located on land which falls within any of the identified natural hazards or adverse construction conditions shown on the maps associated with the Geologic Hazards and Adverse Construction Conditions, St. George—Hurricane Metropolitan Area, Washington County, Utah, 2008, by William R. Lund, Tyler R. Knudsen, Garrett S. Vice, and Lucas M. Shaw, Special Study 127 Utah Geological Survey, a division of the Utah Department of Natural Resources.

B.

Report requirements. The geotechnical report shall include the following:

1.

Conditions and features. A general description of the topography, drainage conditions and surface vegetation. The report shall include surface features such as rock outcroppings, existing structures, debris, and unstable or wet conditions.

2.

Location map. A location map showing the footprints of the planned improvements and the exploration locations with elevations.

3.

Subsurface condition evaluation. An evaluation of the subsurface conditions, including a complete record of the explorations, laboratory test results, and the elevation of the water table, if encountered.

4.

Potential geotechnical constraints. Identification of potential geotechnical constraints on the project site (such as expansive rock and soil, collapsible soil, shallow bedrock and caliche, gypsiferous rock and soil, potentially unstable rock or soil units, shallow groundwater, and windblown sand), and recommendations for their mitigation.

5.

Springs and seeps. The locations of any springs and seeps on the project site, and recommendations concerning the effects of the springs and seeps on the proposed development.

6.

Geotechnical recommendations. Specific geotechnical recommendations for the design and construction of the proposed project, which shall include the following:

a.

A general assessment of the requirements needing to be met to develop the proposed site.

b.

Site preparation and grading, and the suitability of the on site soils for use as structural fill.

c.

Stable cut and fill slopes, including recommendations concerning the effects of material removal and the introduction of water, both on and off site.

d.

Recommendations for foundation type and design criteria, including, but not limited to, bearing capacity of natural or compacted soils, provisions to mitigate the effects of expansive, compressible or collapsible soils, differential settlement and varying soil strength, and the effects of adjacent loads.

e.

Anticipated total and differential settlement.

f.

Special design and construction considerations, as necessary, such as the excavation and replacement of unsuitable materials, excavation difficulties, stabilization, or special foundation provisions for problem soil conditions.

g.

Design criteria for restrained and unrestrained retaining walls.

h.

Soil corrosion.

i.

Moisture protection and surface drainage.

7.

Design recommendations for walls and fill slopes. Detailed design recommendations for any planned rockery walls, mechanically stabilized earth (MSE) walls, and/or reinforced fill slopes.

8.

Slope stability analysis. A detailed slope stability analysis may be required if potentially unstable rock or soil units or slope creep has been identified on the site. The analysis should include, but not be limited to, a determination of shear strength and in some instances residual shear strength, soil saturation, and treatment methods required to provide a minimum safety factor of 1.5 for any slope within the project boundary.

9.

Inspection and certification. It is strongly recommended that the geotechnical firm for the project also provide inspection, testing, and verification services for all grading, foundations, pavement sections, retaining structures, utility line placement, and backfill and any other construction relating to geotechnical aspects of the development. For real property for which development has proceeded on the basis of a geologic or geotechnical report which has been accepted by the City, no final inspection of a subdivision or other improvements shall be completed or certificate of occupancy issued or performance bond released until the engineering geologist or geotechnical engineering firm who prepared and approved the report provides a letter of compliance, in writing, that the completed improvements and structures conform to the descriptions and requirements contained in said report including any approved revisions.

10.

Geology report. The Geologic Hazards and Adverse Construction Conditions, St. George—Hurricane Metropolitan Area Washington County, Utah document and maps prepared by the Utah Geological Survey (current edition) shall be reviewed when considering a site for development. A state licensed professional engineering geologist or a state licensed professional engineer who is trained and experienced in the practice of geotechnical engineering shall prepare the geology report. The geology report may be included in the geotechnical report, and shall include the following:

a.

The location and boundaries of the project site and its general geologic setting.

b.

A description of the specific geologic conditions at the site.

c.

Identification of potential geologic hazards (such as faults, landslides, rockfall, flooding and liquefaction).

d.

Conclusions and recommendations regarding the effects of the geologic conditions and any potential hazards on the proposed development, and recommendations to minimize any hazard to life or property, or any adverse impact on the natural environment.

C.

Development standards. The following minimum standards shall apply to minimize the effect of geologic hazards:

1.

No structures shall be built on or within ten feet of any known fault line, or such distance as may be recommended by a licensed engineering geologist.

2.

No structure or improvement shall be allowed on any area known to be within an active landslide area.

3.

Problems associated with development on or near perched groundwater and shallow groundwater shall be mitigated.

4.

For any development proposed in a rock fall hazard zone as determined by Utah Geological Survey Special Study 127, a geotechnical engineering report shall acknowledge the existence of the hazard and identify where the proposed development is located within the rockfall hazard zone. Platted developments must depict the rockfall hazard zone boundary with a notice to property owners on the recorded plat. Prior to receiving building permit approval on properties within a rockfall hazard zone, the property owner shall record a waiver of liability, in a form approved by the City Attorney, that acknowledges the existence of the rockfall hazard and indemnifies the City against any claims, damages, or liabilities resulting from or related to the rockfall hazard zone, any development therein, and any rockfall event affecting the property at any level of severity.

5.

In addition to the foregoing, a waiver of liability shall be signed by the property owner and recorded with the county recorder in a form approved by the City Attorney, for any parcel where the geotechnical report identifies the potential existence of any of the above hazards.

(Ord. 2014-6, 5-1-2014; Ord. No. 2024-15, 11-21-2024; Ord. No. 2025-07, 4-17-2025)

A.

Floodplain study required. Whenever a proposed building permit or development project is located within two hundred (200) feet of Frog Hollow Wash an engineering analysis shall be prepared which identifies the effect of the 100-year flood or floodway on the building or project site. This 100-year identification shall not be required when a flood study has previously been completed for the area by a licensed civil engineer, and when said study clearly identifies the 100-year flood elevations and floodway for the area and project site.

B.

Habitable floor elevation. Building permits and development plans found to be located within a 100-year floodplain shall be conditioned to require the location of the ground floor of any building a minimum of one foot above the identified 100-year flood. Prior to issuance of final occupancy of any building, a certification shall be prepared by a licensed surveyor or civil engineer, providing the elevation of the lowest habitable floor, noting that the lowest habitable floor is at least one foot above the identified 100-year flood. No buildings shall be allowed within an identified floodway.

C.

Special flood hazard areas. Development within a special flood hazard area or within one hundred fifty (150) feet of a special flood hazard area without an identified floodway as identified on an official flood insurance rate map issued by the Federal Emergency Management Agency shall be required to meet all the requirements of chapter 40, flood damage prevention, of this title.

D.

Prohibited activities. No person shall disturb, remove, fill, dredge, clear, destroy or alter any stream corridor or identified floodway, except as may be expressly allowed by a valid stream channel alteration permit issued by the state department of natural resources.

E.

Required setbacks. Setbacks for any building, structure or improvement located within or adjacent to a stream corridor shall comply with the most restrictive setback requirements of either the zoning district in which it is located, the requirements of the state department of natural resources, or the requirements of the U.S. Army Corps of Engineers.

F.

Runoff controls. All construction and development projects located adjacent to any stream corridor shall apply best management practices as may be required by a federal or state agency with jurisdiction.

G.

Management recommendations. The City Council, Planning Commission, or Zoning Administrator, as applicable, may request recommendations from any federal, state, or local agencies, or other professionals, prior to deciding on an application required for any permit or approval.

(Ord. 2014-6, 5-1-2014; Ord. No. 2024-15, 11-21-2024)

A.

Applicant responsibility. The applicant shall be responsible to contact the U.S. Army Corps of Engineers to determine if a project site contains any wetlands, and obtain necessary permits and meet permit specified requirements as may be necessary. A copy of the permit shall be provided to the Zoning Administrator prior to issuance of a notice to proceed.

(Ord. 2014-6, 5-1-2014; Ord. No. 2024-15, 11-21-2024)

The intent of this requirement is to avoid the unnecessary or inadvertent disturbance of prehistoric or historic human remains and to preserve important archaeological site locations wherever possible. Density transfer and/or including the site in an open space set aside are encouraged as a way to avoid disturbance of important sites.

Location of known important archaeological sites is on file with the City Planning Department. Local landowners are likely aware of substantial sites on their land and should include these in the planning process for a parcel.

(Ord. 2014-6, 5-1-2014; Ord. No. 2024-15, 11-21-2024)