Colorado Water: The South Platte basin calls for more Western Slope water
The second draft of the Colorado Water Plan has been released, but instead of listing specific projects, the statewide plan points to eight regional “basin implementation plans” developed by water-supply planning roundtables.”
And one such regional plan is considered by powerful water interests in the Denver metro area and South Platte River basin to be the necessary water plan for the state, and it includes moving more water from the West Slope to the East Slope.
And at the core of the South Platte plan are potential new transmountain diversion or pumpback projects on the Green, Gunnison, Yampa, Colorado, Blue and Eagle rivers.
The plan also highlights conceptual dam projects on the main stem of the Colorado River west of Rifle and at Wolcott, which would store water pumped up from the Eagle River.
“Investigating, preserving and developing additional supplies from the Colorado River Basin is critical to effectively plan for future water supplies,” states the “South Platte Basin Implementation Plan.”
The dry-up of “hundreds of thousands of acres of agricultural land” is “the default option if decision makers do not exercise the political will to preserve and promote opportunities to develop Colorado River Basin supply for use along the urban Front Range,” the plan says.
The South Platte plan was prepared by consultants at HDR Engineering and West Sage working under guidance from the members of the South Platte and Metro roundtables. It was submitted to the CWCB in mid-April, as were seven other basin implementation plans from other roundtables.
The South Platte and Metro roundtables include representatives from Denver Water, Aurora Water, Northern Water, the South Metro Water Supply Authority, Weld County, Arapahoe County, and the cities of Thorton, Greeley and Loveland, among many other entities.
Water providers in the South Platte River basin now import 400,000 acre-feet of water from the Colorado River basin and another 100,000 acre feet from the Arkansas, North Platte and Laramie river basins.
By comparison, Ruedi Reservoir holds about 100,000 acre-feet of water.
And Front Range water providers see the need for another 195,000 acre feet of water for growing cities and 260,000 acre feet more for irrigation, even though the amount of irrigated land is expected to shrink from 831,000 acres to 635,000 acres.
The South Platte plan calls for minimizing the amount of “buy and dry” occurring on the Front Range by increasing the amount of new water supplies from the variety of rivers that make up the Colorado River basin within the state of Colorado.
“Agricultural water transfers can be reduced if other solutions including the development of Colorado River supplies are more successful,” the plan states.
It’s a concept found throughout the South Platte plan – the more Western Slope water made available to the Front Range, the less ag land will be dried up by expanding cities.
“The South Platte and Metro Roundtables have expressed in many documents and venues that all the available options for water supply development must be pursued simultaneously not sequentially,” the plan says under the heading of “potential future actions.”
“This approach can provide the greatest assuredness that Colorado River Basin water supply may be available for use, thereby reducing the need for East Slope providers to implement large-scale traditional agricultural to water urban water transfers,” the plans also says.
The South Platte plan identifies a range of projects that could deliver new Colorado River water supply to the Front Range and divides them into “large-scale concepts” and “smaller-scale and incremental concepts.”
Under large-scale concepts, there are four “Colorado River transbasin concepts” listed in the plan, and they are on the Gunnison, Green, Yampa and Blue rivers.
The projects have likely all been studied and described in the past in various documents, but they are only briefly described in the South Platte plan.
A potential pipeline from Flaming Gorge Reservoir on the Green River to the Front Range is more fully explored than others, however, in both the main plan and in Appendix F.
The Flaming Gorge pipeline concept has also been studied in-depth by the South Metro Water Supply Authority, which represents 14 water providers in Arapahoe and Douglas counties.
All four of the “large-scale” projects would require new water storage facilities, including, perhaps, underground aquifers on the East Slope.
The Flaming Gorge project involves contracting with the Bureau of Reclamation for 150,000 acre-feet of water from Flaming Gorge Reservoir. It requires a 355-to-442 mile pipeline and pumps to move water 1,400 feet to 3,100 feet up and over the Continental Divide to the Front Range.
“Diversions would likely vary significantly from year-to-year depending on many factors potentially including hydrologic conditions, current storage levels in federal reservoirs (Colorado River Storage Project and Lake Mead), status of compact compliance monitoring, environmental and recreational needs and management strategies as well as Front Range water demands and storage levels,” the South Platte plan says of the Flaming Gorge pipeline.
The South Platte plan also says that Flaming Gorge concept was put forward by the South Metro Water Supply Authority, which “stressed that the concept is now worthy of serious consideration” and “recommends further investigation as a practical and viable means to manage Colorado’s statewide water resources and that the concept be vigorously pursued in subsequent stages of the developing Colorado’s Water Plan.”
The Blue Mesa Reservoir project also would require a water contract with Reclamation, in this case to move water from the Gunnison River through an 81-mile pipeline into the Arkansas River basin, from where the water would then be pumped into the South Platte basin. This requires pumping the water 3,400 feet in elevation.
The Yampa River project would require a 250-mile pipeline and the need to pump water up 5,000 feet in elevation over at least two mountain passes. The project would divert or pump water out of the Yampa near Maybell into a large reservoir.
The South Platte basin implementation plan says that with “large-scale” projects, there may be ways “to help offset the regional impacts of the projects, maximize and distribute statewide benefits, and ensure continued viability of the West Slope’s economy.”
Or, in other words, provide benefits to the West Slope river basins where the water originates.
For example, in turn for taking water out of the Yampa and White rivers, the South Platte plan finds that more infrastructure could be built as part of the transmountain water project to irrigate more land in Moffat Count, and provide more water to Steamboat Springs.
In the Gunnison basin, a new transmountain project could create more storage in the upper Gunnison River basin and help with water quality problems in the lower Gunnison basin.
The South Platte plan also notes that by building new transmountain diversion projects on the Gunnison, Yampa or Green rivers, it might be possible to leave move water in the already seriously depleted headwaters of the Colorado River.
The plan also identifies a series of smaller-scale projects, including ways to leave more water in Green Mountain Reservoir – on the Blue River in Summit County – for eventual use by the Front Range.
The Wolcott Reservoir would be perched on a cliff above the hamlet of Wolcott, where traffic destined for Steamboat Springs leaves I-70.
It would be an “off-channel” dam and reservoir that would store water pumped uphill from the Eagle River.
Once in a new Wolcott Reservoir, the water could be released downstream – which would free up water in Green Mountain Reservoir for Front Range use – or pumped up over Vail Pass and into the Front Range’s existing water diversion systems.
The South Platte plan also describes a pumpback system that could be installed on the Colorado River below its confluence with the Gunnison River in Grand Junction.
Otherwise free-flowing water, destined for Lake Powell, would be pumped from below the confluence back upstream 16 miles so it could either be diverted into the Government Highline Canal.
Or it could be sent back downstream to help a regularly de-watered section of river below the canal, where native fish species are struggling to survive.
In satisfying the senior water rights on the Highline Canal, and helping to keep fish alive – and the federal government at bay – the lower Colorado River pumpback project could also let water stored in Green Mountain and Ruedi reservoirs be used for other purposes.
“A pumpback project on this stretch could provide water for the senior calling rights, therefore reducing the amount of Green Mountain Reservoir water that would need to be released for West Slope beneficiaries,” the South Platte plan notes.
The Webster Hill Reservoir is described in the plan. It’s a dam and reservoir on the main stem of the Colorado River downstream from the city of Rifle where the river bends away from I-70.
“This concept would include a regulating reservoir on the mainstem of the Colorado River with a volume of 30,000 to 40,000 acre feet,” the South Platte says.
The plan also describes two potential “small-scale” projects on the Yampa River.
One is called the “middle Yampa pumpback” and would take from a tributary of the Yampa, the Elk River, and send it through a tunnel under the Continental Divide and the Mt. Zirkel Wilderness Area to the headwaters of the Poudre River basin.
A second is called the “mini Yampa pumpback,” which would take water from the headwaters of the Yampa, including Morrison and Service creeks, to Granby Reservoir and on to the Front Range.
Then there is the Taylor Reservoir pumpback, which requires pumping water from Blue Mesa Reservoir up to Taylor Reservoir, and then sending it under the Continental Divide.
“The water court has previously stated that the yield from this concept would be around 50,000 to 60,000 acre feet,” the South Platte plan notes.
Power and water
The South Platte water-supply plan suggests that the South Platte basin is the most important, and powerful, part of Colorado.
“Considering the various conversations with South Platte basin stakeholders, it seems that one of the key overarching messages that should be conveyed is that a good Colorado plan needs a good South Platte plan,” the plan itself proclaims.
It also says “Colorado lacks a cohesive plan to meet growing Front Range municipal water needs.”
Today, 80 percent of the state’s population lives in the South Platte River basin, which includes the Front Range cities of Aurora, Denver, Boulder and Fort Collins, and many other smaller, but steadily growing cities. Population in the basin, now 3.5 million, is expected to climb to six million by 2050.
According to the South Platte plan, “the single biggest driver of the need for additional water supplies is population growth” and the future water-supply gap in the South Platte basin accounts for 75 percent of the state’s forecasted water gap.
And yet today “agriculture is the dominant water use in the basin, accounting for 85 percent of total water diversions.”
The plan also sounds a “one Colorado” theme.
“There are many factors that support a broad statewide approach to solving South Platte basin water supply issues,” the plan says, including that “regional affiliations are increasingly fluid with offspring of West Slope residents increasingly finding employment and raising families in new South Platte river basin communities.”
Uphill to money
The South Platte plan includes, as Appendix F, a “concept for discussion” put forward by the South Metro Water Supply Authority, which includes a review of how to compensate the Western Slope for the loss of its water.
The Authority’s concept paper finds that “generally, the most useful form of compensation would be unrestricted monetary compensation to be used by the West Slope to compensate unprotected parties and for whatever other purposes its citizenry prefers.”
Rather than committing a certain amount of money for specific projects, the South Platte plan appendix suggests “a development fund” be established “for future water needs or other economic development on the West Slope.”
Front Range money could also be used, the appendix suggests, to try and repair the environmental damage already caused to headwater streams of the Colorado River by Front Range diversions.
Which as the plan put it, could serve as “an early milestone in the process, bringing environmental benefits to the headwaters on the way to project permitting.”
And the paper suggests that the “primary base of funding” for any new transmountain diversion would be “use rates and tap fees,” as “this connects the customers with what they are paying for.”
Two other funding mechanisms are also explored, including a “water” mill levy in nine Front Range counties or a statewide “container fee” on beverage containers, both of which the plan says could generate about $100 million annually for new water projects.
In the analysis of the water mill levy, or property tax, the plan suggests that half of the $107 raised each year – $54 million – could pay for a new water project and the other half “could help provide water and economic development for the West Slope.”
The plan also notes, as a “point of comparison,” that Gunnison County in 2009 only saw $10 million in general fund revenue.
Finding such funding, and building a new transmountain diversion, would mean, according to the South Platte plan, that “transfers of East Slope agriculture would no longer be the dominant strategy for meeting Front Range water needs.”
A state water project?
However, the plan notes that there are “some important factors affect our ability to implement large statewide projects.
“First, smaller water providers on the Front Range, who will likely bear the largest part of the municipal and industrial gap, do not necessarily have the capability to develop new Colorado River Basin supplies on their own and will likely rely on conservation, reuse, and incremental agricultural transfers leading to a large loss of irrigated land in the South Platte Basin.
“Secondly, it cannot be assumed that cities or private investors will be able to build the Colorado River Basin supply projects needed to avoid a large loss of South Platte agriculture.
“A point has been reached in our state’s development where a state water project needs to be considered in order to minimize impacts of buy-and-dry,” the plan states. “This is the essential trade-off that Colorado’s Water Plan must recognize and address.”
Aspen Journalism is collaborating with The Aspen Times and the Glenwood Springs Post Independent on coverage of rivers and water. More at http://www.aspenjournalism.org
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