A state agency overseeing Colorado's water resources warned this week that the state faces a serious future water shortage and that steps should be taken immediately to conserve, reuse and find new water sources to meet growing demand.

The Colorado Water Conservation Board, in a final draft report released this week, analyzed the state's water needs through 2050. Among other things, the report stresses the need for a major shift away from agricultural water use as more water is needed to support a statewide population projected to nearly double to 10 million residents in the next 40 years.

"We need to be paying attention to this now, and we need to be doing something about this now," said Jennifer Gimbel, CWCB's director in Denver, of the 12-page report, which synthesizes thousands of pages of ongoing research by conservation board staff and other experts done over the past several years.

In addition to population growth, the report notes that large volumes of water may be needed to support anticipated development of oil shale -- a still largely experimental process of extracting crude from shale rock, requiring heavy refining and the projected use of billions of gallons of water.

Overall, the state will need to find a staggering 325 billion gallons of water in the next four decades to meet the growing demand, likely through some combination of conservation, reuse or development of new water sources, according to the report.

Though the projections are dire, the CWCB report identifies a number of actions that, if fully implemented, could increase Colorado's water budget by as much as 188 billion gallons annually. They include:

• Developing a plan to replace an estimated 11 billion gallons a year of groundwater in southeast Colorado "with a renewable water supply" that relies on rainwater recharge.

• Transferring billions of gallons of water for agriculture -- by far the biggest consumer of water in the state -- to domestic and industrial uses, including through the buying of water rights.

• Establishing a five-year planning cycle for assessing the state's future water quantity needs, including implementing projects that can help the state meet those needs.

While implementing "these local projects and processes are critical to meeting Colorado's future water supply needs," it will not be easy or inexpensive, the report states, with total cost estimates running to as much as $15 billion.

An ongoing process

The latest recommendations update work begun in 2004 to ensure the state maintains an adequate water supply in the coming decades. The effort, called the Statewide Water Supply Initiative, is updated every few years.

A new analysis of Colorado's future water supply suggests the state could be required to spend $15 billion to expand reservoir capacity to meet the state's growing demand. Photo courtesy of the Colorado Water Conservation Board.

The latest report evaluates water supply needs through 2050 and estimates costs associated with implementing strategies designed to ensure adequate water supply is available in 40 years.

The Colorado Water Conservation Board has scheduled a Jan. 24 public forum to collect public comment on the report and gather ideas about how the recommendations should be implemented.

The CWCB's 15-member board is scheduled to vote Jan. 26 whether to accept and adopt the report and its recommendations, Gimbel said.

If approved, the report should lay the groundwork for local water providers and state lawmakers "to work together on implementing the necessary strategies to meet our near- and long-term future water supply challenges," Gimbel said.

Much of that work would be done by basin roundtables comprised of local government leaders, farmers and advocates spread across the various water basins in the state, she said.

Oil shale and water

While it is relatively easy to estimate population growth and per-capita water consumption, experts said it is more difficult to forecast the impacts oil shale production will have on the state's water supplies. That is mostly due to ongoing uncertainty about whether the technology can be developed to economically extract petroleum from shale rock.

Nevertheless, the CWCB report stresses the risk of Colorado mounting a full-scale effort to tap the state's oil shale reserves. More than half the world's oil shale reserves are in the Green River formation, which covers portions of western Colorado, and some government and industry officials believe the formation contains as much as 1.5 trillion barrels of recoverable oil.

Based on projections, CWCB estimates that the extraction of 1.5 million barrels of oil a day from oil shale deposits would consume as much as 39 billion gallons of water a year, according to the report. More modest oil shale production, in the range of 550,000 barrels a day, would consume as much as 14.3 billion gallons of water per year, according to the report.

Major oil companies with interest in oil shale development, such as Exxon Mobil Corp., Royal Dutch Shell PLC and Chevron Corp., have already started purchasing senior water rights from mostly agricultural users in the Piceance Basin, which lies between the White and Colorado rivers. Both rivers would be tapped to operate drilling equipment as well as to cool turbines at new power plants that would be necessary to support oil shale development projects.

The water use associated with oil shale has been a source of controversy for years. The industry has chafed at projections that it could take as much as three barrels of water to produce every barrel of oil shale.

But David Abelson, Western Resource Advocates' oil shale policy adviser, said the latest numbers validate the group's long-standing concerns about water usage associated with oil shale development.

"We need to ask, 'In an arid region where we know water demand is going to skyrocket, where does oil shale fit in?'" Abelson said. "It would represent a significant change of order in how water is used in the state. And it begs the question: Is oil shale really the best use of that water?"

Click here to view the draft report.

Streater writes from Colorado Springs, Colo.