PUB00084

• Year: 2004
• Title: Artificial Recharge of Ground Water in Colorado -- A Statewide Assessment
• CWCB Section: Administration
• Author: Colorado Geological Survey
• Description: This study was a special assignment to the CGS from the DNR Executive Director. The tqask was to assess the underground water storage options potentially available in our state.
• Publications - Doc Type: Tech Report

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Executive Summary

Throughout the Centennial State's history, its semi-arid climate, periodic multi-year drought
cycles, and the needs of its growing population have all conspired to highlight the need for water
storage. Once again, recent drought and increasing water demands of a growing population have
made Coloradoans critically aware of the need for additional water storage. Surface-water
reservoirs have been the primary means of storing water to meet Colorado's needs, but due to
site logistics, regulatory requirements and public opinion, building large new reservoirs has
become more complicated, requiring years of planning and ever-increasing construction costs.
An alternative means of increasing water-storage capacity is to store water underground in
aquifers and voids .

The extreme drought conditions experienced in 2002 solidified the value of ground water as part
of an overall water management strategy. In 2003, the director of the Colorado Department of
Natural Resources requested that the Colorado Geological Survey conduct a statewide
assessment study of artificial recharge potential. This study assessed the opportunities for using
artificial recharge to meet water storage needs statewide, focusing primarily on the
hydrogeologic properties of aquifers and other underground storage options. The American
Society of Civil Engineers has recently identified six phases of planning that are typically needed
to develop, operate, and maintain a project for artificial recharge of ground water. This study
parallels this process, but represents only the beginning physical data collection and technology
assessment stages of the initial phase.

Artificial recharge (AR) is defined as any engineered system designed to introduce water to, and
store water in, underlying aquifers. This report discusses several aspects important to the
understanding of artificial recharge potential in Colorado, including:

~ The design objectives for implementing artificial recharge;
~ The various artificial recharge technologies available;
~ The current application of artificial recharge in other states and countries;
~ The present practice of artificial recharge in Colorado; and
~ The physical suitability of various aquifers, abandoned mines, and caves to store
water.

The objectives of most AR applications fall into one, or a combination, of the following
categories:
. Manage water supply, including short-term water supply regulation, seasonal storage,
long-term storage (drought mitigation), emergency supply, and conjunctive use.
. Meet legal obligations, such as providing augmentation water, meeting downstream in-
state obligations, or meeting obligations of interstate compacts.
. Manage/mitigate water quality through the improvement of surface- or ground-water
quality or treated wastewater disposal.
. Restore/protect aquifers by restoring ground-water levels, limiting aquifer compaction
and surface subsidence resulting from excessive ground-water withdrawals, or mitigating
saltwater intrusion.
. Protection of the environment by maintaining wetland hydrology, enhancing endangered
species habitat, or controlling the migration of ground-water contamination.