For the purpose of this subchapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
ACCEPTABLE AND REASONABLE RISK. No loss or significant injury to occupants, no release of hazardous or toxic substances and minimal structural damage to buildings or infrastructure during a hazard event allowing occupants egress outside.
ACCESSORY BUILDING. Any structure not designed for human occupancy, which may include tool or storage sheds, gazebos and swimming pools. Accessory dwelling units and businesses located in ACCESSORY BUILDINGS must comply with all requirements of main buildings.
ACTIVITY CLASS OF FAULTS. The activity level of a fault is based on the latest Western States Seismic Policy Council policy recommendation defining “surface faulting,” which can be found at: (https://www.wsspc.org/publicpolicy/adoptedrecommendations/). Currently, policy recommendation 18-3 states that based on the time of most recent movement: Latest Pleistocene-Holocene faults are defined as movement in the past 15,000 years, late Quaternary faults are defined as movement in the past 130,000 years and Quaternary faults are defined as movement in the past 2,600,000 years.
ALLUVIAL FAN. A fan-shaped deposit where a fast-flowing stream flattens, slows and spreads, typically at the exit of a canyon onto a flatter plain.
AVALANCHE. A large mass of predominantly snow and ice, but may also include a mixture of soil, rock and/or organic debris that falls, slides and/or flows rapidly downslope under the force of gravity.
BUILDABLE AREA. Based on an accepted geologic hazard investigation report, the portion of a site not impacted by geologic hazards or the portion of a site where it is concluded the identified geologic hazards can be mitigated to an acceptable and reasonable risk. Buildable areas must be clearly marked on approved site plans and/or final approved plats, as appropriate.
COUNTY COMMISSION. The County Commission of Morgan County, Utah.
CRITICAL FACILITIES. Essential, hazardous, special occupancy and all risk categories III and IV structures, as defined in the currently adopted International Building Code (IBC), and lifelines, such as major utility, transportation, communication facilities and their connections to critical facilities.
DEBRIS FLOW. A slurry of rock, soil, organic material and water transported in an extremely fast and destructive manner that flows down channels and onto and across alluvial fans; includes a continuum of sedimentation events and processes, including DEBRIS FLOWS, debris floods, mudflows, sheet flooding and alluvial fan flooding.
DEVELOPMENT. All critical facilities, subdivisions, single-family dwellings, duplexes and multi-family dwellings, commercial and industrial buildings; also includes additions to or intensification of existing buildings, storage facilities, pipelines and utility conveyances and other land uses.
ENGINEERING GEOLOGIST. A state-licensed professional geologist, who, through education, training and experience, practices in the field of engineering geology and geologic hazards meeting the requirements of § 155.225 of the code.
ENGINEERING GEOLOGY. Geologic work that is relevant to engineering and environmental concerns and the health, safety and welfare of the public. ENGINEERING GEOLOGY is the application of geological data, principles and interpretation affecting the planning, design, construction and maintenance of engineered works, land use planning and groundwater issues.
ESSENTIAL FACILITY. Buildings and other structures intended to remain operational in the event of an adverse geologic event, including all structures with an occupancy greater than 1,000 shall also be considered IBC Risk Category III when not meeting the criteria for IBC Risk Category IV; and IBC Risk Category IV buildings and other structures are designated as ESSENTIAL (CRITICAL) FACILITIES.
FAULT. A fracture in the Earth’s crust forming a boundary between rock and/or soil masses that have moved relative to each other, due to tectonic forces. When the fracture extends to the Earth’s surface, it is known as surface fault rupture or a fault trace.
FAULT SCARP. A steep slope or cliff formed by movement along a fault.
FAULT SETBACK. A specified distance on either side of a fault within which structures for human occupancy or critical facilities and their structural supports are not permitted.
FAULT TRACE. The intersection of a fault plane with the ground surface, often present as a fault scarp, or detected as a lineament on aerial photographs or other imagery.
FAULT ZONE. A corridor of variable width along one or more fault traces, within which ground deformation has occurred as a result of fault movement.
GEOLOGIC HAZARD. A geologic condition that presents a risk to life, of substantial loss of real property, or of substantial damage to real property (UCA § 17-27a-103) and includes, but not limited to surface fault rupture, liquefaction, landslides, slope stability, debris flows, rockfalls, avalanches, radon gas and other hazards.
GEOLOGIC HAZARD STUDY AREA. A potentially hazardous area as defined in § 155.223 of this code within which geologic hazard investigations are required prior to development.
GEOTECHNICAL ENGINEER. A state-licensed professional engineer who, through education, training and experience, is competent in the field of geotechnical or geological engineering meeting the requirements of § 155.226 of this code.
GEOTECHNICAL ENGINEERING. The investigation and engineering evaluation of earth materials, including soil, rock and human-made materials and their interaction with earth retention systems, foundations and other civil engineering works. The practice involves the fields of soil and rock mechanics and the earth sciences and requires the knowledge of engineering laws, formulas, construction techniques and performance evaluation.
GOVERNING BODY. The County Commission, or a designee of the Commission.
INFRASTRUCTURE. The improvements which are required to be installed and guaranteed in conjunction with an approved subdivision or other land use approval. INFRASTRUCTURE may be public or private, on-site or off-site, depending on development design and may include streets, curb, gutter, sidewalk, water and sanitary sewer lines, storm sewers, flood control facilities and other similar facilities.
INTERNATIONAL BUILDING CODE (IBC). The latest, statewide adopted International Code Council International Building Code (UCA Title 15A, https://le.utah.gov/xcode/Title15A/15A.html).
LANDSLIDE. The downslope movement of a mass of soil, surficial deposits and/or bedrock, including a continuum of processes between LANDSLIDES, earth flows, debris flows, debris avalanches and rockfalls.
LEGAL LOT OF RECORD. A parcel of land which meets all zoning requirements to be eligible for the development of a dwelling, habitable structure or other facility or structure, pursuant to all county requirements.
LIQUEFACTION. A sudden, large decrease in shear strength of a saturated, cohesionless soil (generally sand and silt) caused by a collapse of soil structure and temporary increase in pore water pressure during earthquake ground shaking. May lead to ground failure, including lateral spreads and flow-type landslides.
LOT. A parcel or tract of land within a subdivision.
MORGAN COUNTY. The County Public Works Director, Engineer, Planning and Development Services Director, Zoning Administrator, Building Official, Commission Administrator, County Commission, land use authority or another county employee or designee.
NON-BUILDABLE AREA. The portion of a site which a geologic hazard investigation report has concluded is impacted by geologic hazards that present an unreasonable and unacceptable risk, and where the siting of habitable structures, accessory structures which house an accessory dwelling unit or business, or critical facilities, are not permitted.
PARCEL. A piece of land created by a partition, subdivision, deed or other instrument recorded with the appropriate recorder. This includes a lot, a lot of record or a piece of land created through other methods.
ROCKFALL. A rock or mass of rock, newly detached from a cliff or other steep slope which moves downslope by falling, rolling, toppling and/or bouncing; includes rockslides, rockfall avalanches and talus.
SETBACK. An area subject to risk from a geologic hazard within which habitable structures or critical facilities and their supports are not permitted.
SLOPE STABILITY. The resistance of a natural or constructed slope to failure by landsliding and assessed under both static and dynamic (earthquake-induced) conditions.
SNOW AVALANCHE. See definition of “avalanche.”
STRUCTURE DESIGNED FOR HUMAN OCCUPANCY. Any residential dwelling or any other structure used or intended for supporting or sheltering any use or occupancy by humans or businesses, includes all Risk Category II structures as defined in the currently adopted International Building Code, but does not include an accessory building which houses no accessory dwelling unit or business.
TALUS. Rock fragments lying at the base of a cliff or a very steep rocky slope.
(Prior Code, § 8-5I-2) (Ord. 10-02, passed 6-1-2010; Ord. 19-09, passed 10-15-2019; Ord. 21-07, passed 6-15-2021)