U.S. Department of the InteriorU.S. Geological Survey

Groundwater Study For Malad and Bear Rivers Drainages, Box Elder County

Bear River Water Conservancy District

102 West Forest Street

Brigham City, Utah 84302

April 23, 2012

Role of U.S. Geological Survey

Provide hydrologic understanding specifically designed to inform decisions about groundwater development and surface-water rights

Cooperative StudyDivision of Water RightsU.S. Geological Survey

Length of StudyMarch 2012 to March 2015

Funding$360,000

Hydrologic SystemGroundwater ENTERS (recharges) the subsurface flow from

the surrounding mountains and irrigated fields

Groundwater EXITS (discharges) the subsurface along the Bear and Malad Rivers, springs, Bear River Bird Refuge, and Great Salt Lake

L.J. Bjorklund and L.J. McGreevy , 1974, Ground-Water Resources of the Lower Bear River Drainage Basin, Box Elder County, Utah, State of Utah Technical Publication 44

How Groundwater Pumping Affects Surface WaterThe effect of groundwater pumping is a reduction in

natural discharge from the aquifer, an increase in recharge to the aquifer, or some combination

Controlling factors include: Location of pumping wells Permeability of the aquifer Where natural discharge occurs Where recharge occurs

Analysis Tool is Regional Groundwater Flow ModelSimulates the interactions between streams, groundwater,

springs, pumping, irrigation, and mountains

Includes: Permeability of the consolidated rocks in the

mountains Permeability of the sand-silt-clay in the valley Recharge from snow and rain Recharge from irrigation Discharge to wells, springs, streams, and plants

Groundwater Model Reflects Conditions in Early 1970’s

Modify to current conditions

Locations and amounts of irrigation Additional wells Discharge to streams and springs Consideration of field drains

Collection and Examination of Additional Data

Land owner cooperation for access to wells and other measurements sites is essential

Spring flows Stream flows Chemistry Water levels Field drains Land-use changes

Groundwater Model Will Be Used To Create “Capture Map”

San Pedro River, Arizona

Capture maps shows the amount of water that is “captured” or diverted from flowing through the aquifer to the river, due to pumping at a well

Example

An estimated 60% to 70% of water pumped from wells located in yellow areas would normally flow through the aquifer and discharge to the San Pedro River

Contacts

Lynette Brooks lebrooks@usgs.gov 801 908 5014

Tim McKinney tmckinney@usgs.gov 801 908 5060

Bert Stolp bjstolp@usgs.gov 801 908 5061