Recharge areas and quality of ground water for the Glen Canyon and valley-fill aquifers, Spanish Valley area, Grand and San Juan counties, Utah

Evaluation of groundwater resources in the Spanish Valley Watershed, Grand and San Juan Counties, Utah

“…1). Within the Spanish Valley study area, the Moab and Spanish valleys (hereafter referred to as Moab-Spanish Valley) encompass about 23 mi 2 (Steiger and Susong, 1997) and are located within a northwest-trending, elongate trough formed by the collapse of the Moab salt-cored anticline (Lowe and others, 2007); they are not topographically or geologically separable (Sumsion, 1971). In previous studies, the Spanish Valley area, which included both valleys, was defined as stopping at the topographic divide (or watershed boundary) between the Kane Springs Creek watershed and southern Spanish Valley.…”

“…near Moab, to more than 30 in. in the La Sal Mountains (Sumsion, 1971;Blanchard, 1990;Steiger and Susong, 1997). The mean annual temperature near Moab (altitude 4,000 ft) is about 13 degrees Celsius (°C), whereas the mean annual temperature in the La Sal Mountains (altitude 9,580 ft) is about 4 °C (data from SNOTEL (Snow Telemetry) station number 572 accessed November 5, 2018, at https://wcc.sc.egov.usda.gov/nwcc/ site?sitenum=572&state=ut).…”

“…Blanchard (1990) provided a reconnaissance of groundwater conditions in the bedrock aquifers of Grand County and parts of San Juan County, with emphasis on bedrock aquifers in the Mill Creek-Spanish Valley area. Steiger and Susong (1997) presented a map of recharge areas and groundwater-quality data for the Spanish Valley area. Kovacs (2000) developed a numerical groundwater-flow model to investigate the effects of increased well withdrawals in an unincorporated area of Moab-Spanish Valley at the request of the GWSSA.…”

“…The VFA is currently the principal groundwater source of irrigation water in the Spanish Valley area (Blanchard, 1990;Steiger and Susong, 1997;Lowe and others, 2007), although at one time it was the principal source of all groundwater used in Moab-Spanish Valley (Sumsion, 1971). The second is the GCGA, which consists of consolidated rocks of the Glen Canyon Group, namely the Lower Jurassic to Upper Triassic Wingate Sandstone, Kayenta Formation, and Navajo Sandstone (Blanchard, 1990;Freethey and Cordy, 1991;Lowe and others, 2007), and is the principal source of public drinking water (Blanchard, 1990;Steiger and Susong, 1997;Lowe and others, 2007). The water in the VFA is of slightly poorer quality than water in the GCGA, with higher total-dissolved solids concentrations (Steiger and Susong, 1997;Lowe and others, 2007).…”

“…The second is the GCGA, which consists of consolidated rocks of the Glen Canyon Group, namely the Lower Jurassic to Upper Triassic Wingate Sandstone, Kayenta Formation, and Navajo Sandstone (Blanchard, 1990;Freethey and Cordy, 1991;Lowe and others, 2007), and is the principal source of public drinking water (Blanchard, 1990;Steiger and Susong, 1997;Lowe and others, 2007). The water in the VFA is of slightly poorer quality than water in the GCGA, with higher total-dissolved solids concentrations (Steiger and Susong, 1997;Lowe and others, 2007).…”