Moab Valley and the contiguous Spanish Valley comprise a popular residential and recreational area in east-central Utah. Geologic processes that created the rugged and scenic landscape of Moab-Spanish Valley are still active today and can be hazardous to property and life. To address development in areas with geologic hazards, the Utah Geological Survey (UGS) conducted a geologic-hazards investigation to provide information to Moab City and Grand County to help guide development and reduce losses from geologic hazards. This report includes maps of Moab Valley and the northern and central parts of Spanish Valley that provide information on geologic hazards to assist homeowners, planners, and developers in making informed decisions. The maps show areas where hazards may exist and where site-specific studies are advisable prior to development. The maps are for planning purposes only, and do not preclude the necessity for site investigations. Site-specific studies by qualified professionals (engineering geologists, geotechnical engineers, hydrologists) should evaluate hazards and, if necessary, recommend hazard-reduction measures. Because of the small scale of the maps, some hazard areas are not shown; hazard studies are therefore recommended for all critical facilities (for example, hospitals, schools, fire stations), including those outside the mapped hazard areas.

Large, damaging earthquakes can happen in many parts of Utah. Therefore, when choosing where to live in this state, we should be aware of the earthquake risk. It is important to know what potential earthquake hazards exist in an area, and what action we can take to reduce the earthquake risk to ourselves and our families. This brochure introduces homebuyers and others to earthquake hazards so that informed choices can be made when selecting homes, building sites, or hazard-reduction measures.

The purpose of this study is to provide tools for water-resource management and land-use planning; to accomplish this purpose we (1) characterize the relationship of geology to ground-water conditions in the Glen Canyon and the unconsolidated valley-fill aquifers, (2) classify the groundwater quality of the Glen Canyon (east of the valley only) and valley-fill aquifers to formally identify and document the beneficial use of ground-water resources, and (3) apply a ground-water flow model using a mass balance approach to determine the potential impact of projected increased numbers of septic-tank systems on water quality in the valley-fill aquifer and thereby recommend appropriate septic-system density requirements to limit water-quality degradation