The health of our waters is the principal measure of how we live on the land — Luna Leopold
Upper #ColoradoRiver Basin Water Forum Day 1 recap #COriver #aridification @WaterCenterCMU
In 1922, Federal and State representatives met for the Colorado River Compact Commission in Santa Fe, New Mexico. Among the attendees were Arthur P. Davis, Director of Reclamation Service, and Herbert Hoover, who at the time, was the Secretary of Commerce. Photo taken November 24, 1922. USBR photo.
FromThe Grand Junction Daily Sentinel (Dennis Webb):
Demand management “is a form of insurance,” Anne Castle said at the ninth annual Upper Colorado River Basin Water Forum, which continues today and is presented by CMU’s Ruth Powell Hutchins Water Center…
Castle and John Fleck, director of the University of New Mexico Water Resources Program, recently released a report evaluating the risk of future curtailment of river water use in Upper Colorado River Basin states under a 1922 river basin compact. The report discusses the concept of working to take an insurance-based approach to address the risk of curtailment.
“As with any form of risk, you can insure against it,” Castle said…
Earlier this year, Congress approved legislation allowing implementation of drought contingency agreements involving both Upper and Lower basin states. The agreements are aimed at helping keep water levels in Lake Powell and Lake Mead from falling so low as to jeopardize hydropower production and force water supply reductions. In the Upper Basin, an agreement allows in part for any water conserved by possible demand management programs to be stored in a separate account in Lake Powell to protect the reservoir’s water levels.
Colorado and other Upper Basin states since have begun exploring the possibility of pursuing demand management programs. Becky Mitchell, director of the Colorado Water Conservation Board, said at Wednesday’s forum that in Colorado, nearly 100 members of work groups have been meeting as the state begins “to investigate just the feasibility of that program.”
Colorado is looking into issues surrounding the idea of a possible program involving temporary, compensated, voluntary reductions in use by agricultural and other water users.
Castle said demand management is complex and “not an easy solution but it does give us the opportunity to plan and we can hedge our bets a little bit.”
[…]
Castle said a legal question surrounds whether the 1922 [Colorado River Compact] requirement not to deplete water means a requirement to deliver it.
If it only means don’t deplete, the Upper Basin is fine as as long as it doesn’t use more than 7.5 million acre feet a year under the 1922 compact, she said. But if it must deliver that much, it bears all the risk of climate change and reduced river flows in future years, she said…
Meanwhile, climate scientists have projected a 20 to 30% reduction in the river’s flows by mid-century, and a 35 to 55% drop by the end of the century…
She said demand management would have costs, including payments to water users and secondary impacts. Some on the Western Slope want to ensure that temporary cutbacks in use aren’t borne disproportionately by agricultural users, harming rural economies.
Castle said the costs of curtailment need to be considered as well, and those costs could be greater, could last longer and potentially can’t be planned for.
Curtailment would particularly affect municipal transmountain diversions of Colorado River water to the Front Range, because those generally involve more junior water rights.
But Castle and Fleck note in a white-paper, summary version of their report, “While that might sound superficially attractive to West Slope agricultural interests, such a prospect could motivate affected municipal water providers to buy or lease pre-Compact West Slope irrigation water rights, possibly in substantial volume. Although these would almost certainly be market-based, arms-length transactions, the resulting economic impact could be geographically concentrated and tremendously disruptive to commodity supply chains and rural communities.”
Declining flows could force Southwest water managers to confront long-standing legal uncertainties, and threaten the water security of Upper Basin states of Colorado, Wyoming, Utah and New Mexico.
A new paper by Anne Castle at the University of Colorado-Boulder and John Fleck at the University of New Mexico identified many risks facing the basin. These risks need to be addressed in order to avoid disaster for the Colorado River, a water source relied on by more than 40 million people in the southwestern U.S. and Mexico, the paper’s authors wrote. (Some of Castle’s work receives funding from the Walton Family Foundation, which also supports KUNC’s Colorado River coverage).
Reclamation’s forecast for Lake Mead elevations using both the full hydrologic record from 1906 to 2017 and the stress test hydrology.
Much of the risk lies in the relationship between the river’s two basins. Ambiguity exists in the language of the river’s foundational document, the Colorado River Compact. That agreement’s language remains unclear on whether Upper Basin states, where the Colorado River originates, are legally obligated to deliver a certain amount of water over a 10-year period to those in the Lower Basin: Arizona, California, and Nevada.
According to that document, each basin is entitled to 7.5 million acre-feet of water, with the Lower Basin given the ability to call for its water if it wasn’t receiving its full entitlement. That call could result in a cascade of curtailments in the Upper Basin, where cities and farmers with newer water rights would be shut off to meet those downstream obligations. That’s a future scenario water managers need to acknowledge and plan for, Castle argues…
Back in the early 2000s the Colorado River basin saw one of its driest periods on record. Castle and Fleck’s analysis suggests that if that the dry period from 2001 to 2007 were to repeat, within a few years the river’s biggest reservoirs would decline so rapidly that the threat of a Lower Basin call would become much more real.
In the long term, Castle said, the risk grows even higher. Layer on climate change models, which project that the river will likely experience significant declines in coming decades, and “things get pretty serious pretty quickly,” Castle said.
Much like the calculation of whether or not to buy insurance to hedge against a catastrophic or costly loss of home, car or health, Castle said the Upper Basin states need to fully explore what kinds of risks they’re facing when it comes to water supplies from the Colorado River.
