The Arikaree River at Beecher Island in Yuma County, Colorado, February 2017. The groundwater level is indicated by the pooling of water in the bed of the otherwise dry river channel. Water will fill low spots in the channel that are deep enough to reach the water table. Photo credit: Jeffrey Beall, Wikimedia Commons

New Colorado Groundwater Atlas released

2020-06-07 | CGS Admin

Everyone knows that water, wherever it might be found—at the surface or underground—is essential for life. However, few people are aware that groundwater is everywhere beneath their feet. It fills the pore spaces between grains of soil, sand, and gravel as well as the fractures and voids in hard bedrock (Figure 02-01). It may be just below the surface—accessible by digging with simple garden tools, or it may be hundreds of feet down in hard rock—requiring expensive drilling with specialized equipment.

As a resource, groundwater is crucial to the lives and well-being of the residents of Colorado. To address this broad importance of water across the state, the Colorado Water Conservation Board (CWCB) developed and implemented a general water plan with its supporting Analysis and Technical Update. At the same time the Colorado Department of Public Health and Environment (CDPHE) is developing a statewide groundwater protection plan that will identify aquifer vulnerability to pollution. With a long history of involvement in water issues around the state, the CGS hydrogeology team was brought in to augment the science and develop a comprehensive online portal to the geoscience information behind these efforts.

After several thousand hours of research—including the detailed compilation of all available groundwater data from around the state—the CGS is pleased to announce the formal release of our new web-based Colorado Groundwater Atlas. Building on our award-winning 2003 Ground Water Atlas of Colorado, this new compilation provides detailed information about groundwater resources, administration, and quality in addition to comprehensive descriptions of the many aquifers and basins found across the state.

Detailed in the Table of Contents, Sections 1-8 of the Atlas provide an introductory exploration of the fundamentals of groundwater in general, and the specifics of groundwater in Colorado: the scientific, the geologic, the statutory. Following those, Sections 9-12 are more technical discussions of particular aquifers and aquifer types, along with detailed discussions of the various basins. Section 13, in conclusion, presents a concise outline of the geologic evolution of the state in relation to the current presence of groundwater resources.

When a geologic formation is able to yield groundwater to a well or spring it is called an aquifer. Colorado is a mosaic of different types of geologic formations (Figure 13-01) which makes for many aquifers of many types. Precisely where usable groundwater may be found depends entirely on the particular location within the state’s diverse geology. The Atlas addresses this location issue comprehensively with a multi-layer GIS map and a downloadable GIS dataset—both these are augmented with meticulous metadata—providing provenance, processing, and background information. Also included in the GIS are layers of aquifer distribution and other characteristics found in the public domain but presented in a common GIS format for the convenience of more technical users.

All content in Atlas will be subject to ongoing updates as new information and data become available. Groundwater in Colorado is an ever-changing discipline as many agencies, public entities, and academic institutions are constantly gathering new information to better understand and manage this critical resource. As a web-based information source, this Atlas provides a flexible platform where data can be added as it becomes available. The CGS plans to identify, process, and present pertinent additional data so that the users have access to the most useful information on a timely basis.

We consider you, the users, to be our best source for feedback and potential information that may not be readily available through normal research. If you have access to, or know about new data on any of the aquifers, basins, or regions that you feel would enhance the content of the Atlas, please contact us.


Main Atlas landing pageincludes Table of Contents, linked list of Tables and Figures, and the primary Atlas contents.

Atlas Bibliography and Glossaryextensive Bibliography for the project along with a Glossary of groundwater-related terms.

Main online (GIS) Atlas mapcomprehensive GIS map including all aspects of available groundwater data. Complete metadata is also included.

Current Atlas data downloadthe most current (20 May 2020) downloadable GIS dataset, also includes a full set of high-resolution Figures and Tables from the Atlas.

Contact Us: Groundwater Atlas

Colorado Geological Survey
Street and Mailing Address:
1801 Moly Road
Golden, Colorado 80401

telephone :: [+1] 303-384-2655

email ::

  • Use this form to ask us … anything!

Citations, Categories & Tags


Citation: Barkmann, Peter E., Lauren D. Broes, Martin J. Palkovic, John C. Hopkins, Kenneth Swift Bird, Lesley A. Sebol, and F. Scot Fitzgerald. “ON-010 Colorado Groundwater Atlas.” Geohydrology. ON-010 Colorado Groundwater Atlas, 08 January 2020.


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