The ditch that moves water from Lost Man Reservoir to Grizzly Reservoir and then under the Divide to the South Fork of Lake Creek and the Arkansas River.
The ditch that moves water from Lost Man Reservoir to Grizzly Reservoir and then under the Divide to the South Fork of Lake Creek and the Arkansas River.Smith / Aspen Journalism Credit: Brent Gardner-Smith / Aspen Journalism

DENVER— Front Range water users seeking new supplies of Western Slope water said last week they may settle for a reduction in diversions during dry years to accommodate the existing demands of people in western Colorado and downstream in states like Nevada and California.

Mark Waage, the manager of water resources planning for the utility Denver Water, told a meeting of the Interbasin Compact Committee (IBCC) in Denver that Front Range interests are not necessarily seeking “firm yield,” or reliable annual supply, from a new trans-mountain diversion project, but instead could settle for diverting water only when a wet winter like this one gives the Western Slope and downstream consumers more than they need to satisfy existing water rights.

“We are looking for wet year water,” said Waage after the meeting. “There are going to be wet years when we can develop more water. In dry periods, this project wouldn’t divert from the Colorado [River], and we would rely on [buying water rights from] Front Range agriculture instead,” along with reservoir and groundwater aquifer storage and mechanisms like rotational fallowing that permit farmers to temporarily lease their water rights to cities.

The suggestion by Front Range interests that they’re willing to forego diversions during dry years stands in sharp contrast to their usual and long-standing insistence that “firm yield” for the Front Range from new trans-mountain diversion projects is inevitable.

Existing diversion projects — like the Twin Lakes tunnel underneath the Continental Divide between the Roaring Fork and Arkansas river basins — already have the capacity to pipe as much as 600,000 acre-feet (roughly six Ruedi Reservoirs) of water to the Front Range each year.

But with Colorado’s population expected to double by 2050 and the Front Range likely to host most of the growth, officials charged with ensuring a secure water supply for that region have long characterized a new project as essential for their continued prosperity.

Just how much of the “new supply” sought by the Front Range will come from the Western Slope remains a looming question as officials work to draft a statewide water plan as ordered by Colorado Gov. John Hickenlooper last year.

The Colorado Water Conservation Board (CWCB) has been charged with preparing the plan, and a draft is due in December. The CWCB is taking input on the plan from the IBCC, a 27-member group comprised largely of the leaders of nine “basin roundtables” located throughout the state and charged with tracking local water supplies and demands and ensuring that statewide water policy reflects local concerns.

The roundtables themselves will also weigh in on the statewide water plan, by submitting detailed inventories of their projected water needs and supplies over the next 40-odd years to the IBCC. Drafts of those inventories, called “Basin Implementation Plans,” are due in July.

In the meantime, members of the IBCC will now take the emerging framework for a new trans-mountain diversion project back to their respective roundtables for input, before drilling down further on the details in future meetings.

Any agreement on a new project that parties on opposite sides of the Continental Divide can hammer out will likely be reflected in the statewide water plan. Still, the plan itself won’t explicitly endorse any proposed new projects.

“We’re not going to pick winners and losers, or projects that are given a green light, so to speak, or a red light, so to speak,” said James Eklund, the executive director of the Colorado Water Conservation Board, which oversees the IBCC and the roundtables.

Eklund spoke at a meeting with state legislators on the statewide water plan that took place in February. “Instead what we’d like to do,” he said, “is focus on a regulatory path where we might be able to someday have the state endorsement of a project.”

A full Grizzly Reservoir on June 25, 2011. The relatively small reservoir holds water until it can be diverted to the Front Range.
A full Grizzly Reservoir on June 25, 2011. The relatively small reservoir holds water until it can be diverted to the Front Range. Smith Credit: Brent Gardner-Smith

A breakthrough of modest 

For the IBCC members charged with protecting water supplies on the Western Slope, who have long clashed with Front Range cities over the idea of new trans-mountain diversion projects, Waage’s modest statement last week on behalf of Denver Water— vague and general though it was — sounded like something of a breakthrough.

“They are now willing to talk about a project that’s not going to divert every year, and that’s new,” said Jim Pokrandt, communications and education director for the Colorado River District, which protects Western Slope water interests. “There seemed to be a coalescing around a project that would only work intermittently.”

Eric Kuhn, the Colorado River District’s general manager, said that although Front Range water interests have long hinted that they might accept a new trans-mountain diversion project that doesn’t pull water every year, “this is the first time that the idea has surfaced with some consensus.”

In the long and bitter history of Colorado water negotiations, observers said it was also significant to see a six-hour water meeting between parties on opposite sides of the Continental Divide end without significant disagreement.

“I think we’ve made a quantum leap with this here today,” said Kevin McBride, who represents the Yampa and White River Basin Roundtable at the IBCC. “But I think we’re running up against a lot of very technical discussions to take this much further.”

Indeed, the emerging concept of a new trans-mountain diversion project is still in broad, general terms, and there are many bedeviling details to work out before such a project moves forward.

“The most difficult questions now will be what constitutes a dry year and what the triggers will be to limit diversions from a new project,” said Carlyle Currier, a member of the IBCC who represents the Colorado River Basin Roundtable.

Specifically where a new trans-mountain diversion project would be located also remains to be seen. Front Range interests have proposed several possibilities in recent years, including projects pulling anywhere between 100,000 and 250,000 acre feet from the Green River at Flaming Gorge Reservoir in Wyoming, from the lower Yampa River, or from the Gunnison River at Blue Mesa Reservoir west of Gunnison.

The Roaring Fork River above Aspen. About 37 percent of the Fork is diverted under the Continental Divide each year.
The Roaring Fork River above Aspen. About 37 percent of the Fork is diverted under the Continental Divide each year.

The thirsty elephant in the room

To even stand a chance of building a new trans-mountain diversion project, Front Range water interests will have to allay fears now prevalent on the Western Slope that such a project could someday cause Colorado to fall short of its obligations under the Colorado River Compact, a 1922 agreement between seven western states governing the allocation of water rights on the river.

Under the compact, Colorado is required to deliver 7.5 million-acre feet of water over a rolling 10 year period to states in the lower Colorado River Basin, including Nevada, Arizona and California. If Colorado delivers less than that, the lower basin states have the legal right to call for more water, potentially forcing some owners of post-1922 water rights to curtail their use.

Since many of the water rights now used by the Front Range to divert Western Slope water under the Continental Divide were adjudicated after 1922, there’s a chance that a so-called “compact call” would force some Front Range water interests to stop diverting water temporarily.

Faced with the insatiable demand of their urban customer base, those Front Range interests could then begin leasing water from farmers on the Western Slope in order to continue their usual diversions, extending into western Colorado the practice of “buy and dry” water transfers from farms to cities that is now common on the Front Range.

To alleviate fears of such a scenario playing out, Waage of Denver Water told the IBCC meeting last week that the Front Range would be willing to assume the “hydrologic or legal risk” associated with a new diversion project, meaning that diversions from the project would cease in the event of a compact call before Western Slope water users with more senior rights had to curtail their own use.

“The risk of compact curtailment has been a stumbling block for years, and we are looking now at how to minimize and share that risk,” said Waage. “We need to look at water projects that won’t lead to the curtailment of the Western Slope’s Colorado Compact allocation.”

Still, many Western Slope water planners are skeptical that enough un-allocated water remains in a typical year to build a new diversion project without jeopardizing existing water rights.

“I think to decide whether there is enough water, the Front Range would have to do a very detailed risk analysis,” said Kuhn of the Colorado River District. “Because of climate change, we know that the [water supply] baseline is going to change. I think most of the science suggests that we will not have more water in the future than we do now.”

Editor’s Note: Aspen Journalism’s Water Desk and the Aspen Daily News are collaborating on coverage of regional rivers and water. The Daily News published this story on Monday, March 31, 2014.