North Ada County Hydrogeologic Investigation

IDWR conducted a detailed investigation of North Ada County to obtain a better understanding of the hydrogeology of the area with respect to the groundwater resources available for allocation.
The project resulted in a comprehensive report that summarized the hydrogeology of North Ada County and provided a detailed water budget to be used in support of water management decisions in the area.

North Ada County is currently undergoing intense land and water resource development in an area that has been historically undeveloped, and the groundwater resources are not fully understood.
Groundwater is currently being sought as the water supply for the large development projects proposed in the area.

The North Ada County Hydrogeologic investigation was conducted as one technical component to the
Treasure Valley Comprehensive Aquifer Planning and Management Program (CAMP).
The water management plan for the Treasure Valley is designed to address water supply and demand issues looking out 50 years into the future.
This investigation provided the technical information to characterize the surface and groundwater resources in the North Ada County portion of the Treasure Valley.

Funding for this project was based on the 2008 Legislature approval of
House Bill 428 and
House Bill 644 establishing the Statewide Comprehensive Aquifer Planning and Management Program (Idaho Code §
42-1779) and the Aquifer Planning and Management Fund (Idaho Code §
42-1780).
The timeline for this project was from 2009 through 2012.

Purpose and Objectives

The purpose of this project was to provide a scientific foundation for management of the water resources in North Ada County.
The study resulted in the development of a comprehensive technical report of the groundwater systems in North Ada County for use in water management decisions of the area.
Specific objectives included:

• Aquifer Characterization – Delineate the extent and thickness, hydrogeologic properties, and hydrogeologic boundaries of the various aquifers in the area.
• Hydrologic Data Collection – Develop a groundwater monitoring network of existing wells, installation of long term monitoring wells, measure surface water gains or losses in the area, and determine current water usage and demand rates for the area.
• Water Quality – Collect water quality samples to determine general water quality and potential recharge rates in the aquifers.
• Public Involvement – Convey information about regional water resources and knowledge gained from the study to state and local decision-makers, the professional community, and the general public through published reports and public meetings.

Reference Material for the North Ada County Hydrogeologic Investigation

Orders

• Amended Preliminary Order in the Matter of Applications to Appropriate Water Nos. 63-32089 and 63-32090 in the Name of the City of Eagle – October 3, 2007
• Final Order in the Matter of Applications to Appropriate Water Nos. 63-32089 and 63-32090 in the Name of the City of Eagle – February 26, 2008
• Recommended Order in the Matter of Application for Permit No. 63-32061 in the Name of Suncor Idaho, LLC – March 13, 2007

Technical Publications

• Seasonal Seepage Investigation on an Urbanized Reach of the Lower Boise River, Southwestern Idaho, Water Year 2010 – 2011
• Distribution of Isotopic and Environmental Tracers in Groundwater, Northern Ada County, Southwestern Idaho – July 2010
• A Distributed Parameter Water Budget Data Base for the Lower Boise Valley – January 2008
• Development of a Numerical Groundwater-Flow Model for the M3 Eagle Development Area Near Eagle, Idaho – December 2007
• Bibliography of the Hydrology of North Ada County – September 2007
• Water Budget for the Treasure Valley Aquifer System – 1996 & 2000 – March 2004
• Streamflow Gains and Losses in the Lower Boise River Basin, Idaho, 1996-1997 – 1999
• Geologic and Tectonic History of the Western Snake River Plain, Idaho and Oregon – July 1998
• Groundwater Quality Characterization and Initial Trend Analysis for the Treasure Valley Shallow and Deep Hydrogeologic Subareas (WIB#50, Part 3) – March 1998
• Groundwater Analysis of Emmett, Idaho – May 1996
• Seismic Expression and Geological Significance of a Lacustrine Delta in Neogene Deposits of the Western Snake River Plain, Idaho – January 1994
• Radiometric Dating, Volcanic Stratigraphy, and Sedimentation in the Boise Foothills, Northeastern Margin of the Western Snake River Plain, Ada County, Idaho – May 1993
• Groundwater Conditions in the Dry Creek Area, Eagle, Idaho – June 1991
• Progress Report on Drainage Investigations, Emmett Valley, Gem County, Idaho – May 1954
• Progress Report on Drainage Investigations, Emmett Valley, Gem County, Idaho – June 1953

Meeting Materials

• 2010 Meeting Documents
• 2009 Meeting Documents
• 2008 Meeting Documents
• 2007 Meeting Documents

Data & Reports

• Monitoring Sites
• Consultant Reports
• Lithology Plot (Shallow)
• Lithology Plot (Deep)

Water Right Documents

• 63-12125 Willowbrook
• 63-12448 Eagle
• 63-31511 Trellis Subdivision
• 63-31656 High Plains
• 63-31679 Monarch Ridge
• 63-31770 High Plains
• 63-31862 Willowbrook
• 63-31966 Avimor
• 63-32061 Avimor
• 63-32089 Eagle
• 63-32090 Eagle
• 63-32423 Dry Creek
• 63-32573 M3

Related Links

• Treasure Valley CAMP
• CGISS – Boise State University
• Dry Creek Experimental Watershed – Boise State University
• M3 Development
• Avimor (SunCor)