The Colorado River Basin drains parts of( Arizona, California, Colorado, New Mexico,(Nevada, Utah, and Wyoming and is vital to (the economy, culture, and ecology of the region. Aquifers underlying the Colorado River basin provide, in addition to other uses, about 875,000 acre-ft per year of fresh water to the nearly40 million inhabitants of the region and about 2 million acre-ft per year of fresh water to agriculture for irrigation. The U.S. Geological Survey, in cooperation with 12 stakeholders, monitors routine groundwater levels in about 110 wells and project-focused groundwater levels in another 330 wells throughout the Colorado River Basin to inform short and long-term water resource planning decisions.

• 431 wells with current water-level information
• 72 wells monitored continuously and data available online
• 25 wells monitored continuously, but data are not available online
• Longevity of Records, are as follows:
  
• 213 - Number of wells with 10+ years of data
• 16 - Number of wells with 50+ years of data
• 2018 Groundwater Levels are as follows:
  
• 22 - Number of wells with record high levels
• 102 - Number of wells with record low levels *based on 5+ years or more of data

 DOCUMENTS

1995 - USA Groundwater Atlas. USGS.

1995 - Groundwater Atlas of Arizona, Colorado, New Mexico and Utah

1995 - Groundwater Atlas of California and Nevada

1995 - Groundwater Atlas of Basin and Range Aquifers

1999 - Land Subsidence in the United States. Galloway et al.

2005 - Estimated Withdrawals from Principle Aquifers in the United States, 2000. Maupin and Barber. Maupin and Barber. 2005.

2005 - Estimated use of water in the United States. US Geological Survey.

2006 - Dissected hydrologic system at the Grand Canyon: Interaction between deeply derived fluids and plateau aquifer waters in modern springs and travertine. Crossey.

2007 - Groundwater [Natural] Recharge in the Arid and Semiarid Southwestern United States. Stonestrom et al. 

2008 - Groundwater Availibility in the United States. Reilly et al

2014  - Groundwater Depletion During Drought Threatens Future Water Securit in the Colorado River Basin. Castle et al.

2016 - The Importance 0f Base Flow in Sustaining Surface Water Flow in the Upper Colorado River Basin. Miller.

2016 - Hydrologic Asessment of Surface and Water Resources in Castle Valley, UT; Analysis and Water Budget;Final Report Phase 1

2017 - How Much Groundwater Did California's Central Valley Lose During the 2012 - 2016 Drought? Xiao et al.

BOOKS