The Utah Geological Survey performed a one-year study of the hydrogeology of the Powder Mountain area to better understand the hydrologic connection between springs, streamflow, and new water wells in adjoining parts of Cache and Weber Counties. The study included measuring stream discharge during baseflow conditions, measuring water chemistry, examining geology, and analyzing data from an aquifer test.

This report characterizes the relationship of geology to groundwater occurrence and flow, with emphasis on determining the thickness of the valley-fill aquifer and water yielding properties of the fractured rock aquifers. Develops a water budget for the drainage basin and classifies the groundwater quality and identifies the likely sources of nitrate in groundwater.

This CD contains a 125-page comprehensive study of the hydrogeology of Cedar Valley, Utah County, located in north-central Utah. The report includes 72 figures; two plates, one of which is a potentiometric map of the basin-fill, bedrock, and several perched aquifers; and seven appendices of data. Field investigations included groundwater chemistry sampling, regular water-level monitoring, and multiple-well aquifer testing. The field data were incorporated into a 3D digital groundwater flow model using MODFLOW2000. Seventy percent of the recharge to the Cedar Valley aquifer system is from precipitation in the Oquirrh Mountains. Groundwater generally flows from west to east and exits the aquifer system mostly as interbasin flow through bedrock to the northeast and southeast. The groundwater model showed a 39-year (1969-2007) average recharge to the Cedar Valley groundwater system of 25,600 acre-feet per year and discharge of 25,200 acre-feet per year. A significant volume of precipitation recharge (perhaps 4300 acre-feet per year) does not interact with the basin-fill aquifer but travels within bedrock to discharge to adjacent valleys or as bedrock well discharge. 125 pages + 2 plates