Nearby water basins eye Blue Mesa as potential water bank

Inter-basin study first of its kind

In a proposal that would be the first of its kind since the creation of the 2005 Colorado Water for the 21st Century Act, the Gunnison and Arkansas Water Basins are coming together to study the feasibility of using Blue Mesa Reservoir for the storage of a Colorado water bank.

This spring, the Colorado Water Conservation Board approved the use of $245,000 from the Water Supply Reserve Account to conduct a feasibility study. Groups representing the basins came together on Friday, May 6, to get the ball rolling.
“The study will examine the use of Blue Mesa Reservoir capacity to store water in the event that a water bank is a useful response to a lower basin call under the Colorado water compact of 1922,” said John McClow, general counsel for the Upper Gunnison River Water Conservancy District (UGRWCD).
The Colorado Water Compact of 1922 guarantees lower basin states the right to an uninterruptable supply of 7.5 million acre-feet of water per year. In times of low water availability, a call on the water compact could curtail post-1922 water rights.
According to McClow, the thinking behind the Blue Mesa study is, “if water is imminent or a call is placed, it will be a dry period so the Blue Mesa Reservoir will not be full. There could be empty space there to store other water.”
Cooperation between the Arkansas Basin and the Gunnison Basin was inspired by the Water for the 21st Century Act that created the Interbasin Compact Committee. According to the UGRWCD general manager Frank Kugel, the IBCC was established to “encourage ‘the equitable distribution of the state’s waters’ between basins.”
“Members of the Arkansas Basin Roundtable see this as an insurance policy in the event of a Colorado Compact curtailment,” Kugel explained. “Any excess storage capacity in Blue Mesa Reservoir could conceivably be released downstream as an exchange to allow existing out-of-priority trans-mountain diversions from the Roaring Fork basin to continue.”
The Blue Mesa feasibility study, which only considers storage capacity, is one of three studies currently examining potential curtailment. Where the water itself would come from is being addressed in a Colorado Water Bank Study Group spearheaded by the Colorado Water Conservancy District (CRWCD), the Southwest Water Conservation District, the State of Colorado and the Nature Conservancy.
“In the Colorado River system, there’s about a million acre-feet of depletion above the 15-mile reach in the Colorado River, and roughly half of that gets diverted to the Front Range,” said Dan Birch, CRWCD deputy general manager. “Of that 500,000 acre-feet, the vast majority are post-compact. One scenario for curtailment would have every water right post-1922 be curtailed. So obviously, this is of interest and concern. One idea would be to have a water bank to keep post-compact critical uses going. The other aspect is to try to prevent curtailment.”
According to Birch, the water bank study will look into market-based transactions that could buy or lease senior water rights. A third study, the State of Colorado Compact Compliance Study, is looking into what curtailment could look like, assessing factors like which water rights would be curtailed first.
“Everybody is looking at slightly different aspects, but they’re closely related, and we’ve got good communication going between all three groups, coordinating, using each other’s information. All of the studies got going for slightly different reasons, but we’re working hard to make sure we are coordinating and not duplicating,” Birch said.
That risk of duplication became much of the focus at the May 6 meeting between the Arkansas and Gunnison basins, which sought to identify next steps for the Blue Mesa study.
“When we look at the defined versus published scope of work, was there modification and has anyone seen it?” asked Jim Broderick, executive director of the Southeastern Colorado Water Conservancy District. “We want to make sure that whatever [agreement] we sign is consistent with no overlap.”
While the group agreed that it is essential to find a contractor with the technical modeling expertise and an integral understanding of the Bureau of Reclamation, which owns the reservoirs involved in both water bank studies, they placed additional emphasis on following a clear and concise process. The inter-basin study will set the precedent for future inter-basin cooperation.
“If we don’t do this right, then the model used other places will have problems,” Broderick said. “I think we’ve got an opportunity here in taking a long step forward to what the governor wants to see. There’s been communication between roundtables before, but it’s been meaningless. There’s a real opportunity here.”
The group agreed, acknowledging the momentum behind inter-basin communication and the need to not only get the study going but also take advantage of the partnership to bring other discussions and ideas to the table.
“In my view, we have enough folks with enough motivation to get this done,” said Jay Winner of the Lower Arkansas Valley Water Conservation District.
“There’s no reason for this to be on a single track—let’s parallel path it,” Broderick said.
The Blue Mesa study and the Water Bank study groups planned to meet the week of May 16 to compare project scopes, after which the Arkansas and Gunnison Basins will prepare proposals from contractors. The invitation to submit will likely go out middle to late June.