River demands exceed supplies; states at risk
The unfounded optimism that underlaid the structure of the 1922 Colorado River Compact might soon take a toll on Colorado and the other sparely populated mountain states that send water south and west to more arid, and more populous states downstream, said the general manager of the Colorado River Water Conservation District.
The upper basin states of Colorado, Utah and Wyoming are obligated under the 1922 agreement governing the management of the river to deliver 75 million acres feet of water at Lee’s Ferry in Arizona every 10 years, or 7.5 million acre feet every year, on a rolling average.
There is a distinction and it could be significant because of the lower basin states of Arizona, California and Nevada, Eric Kuhn said Monday at the Colorado Mesa University “Natural Resources of the West: Water and Drought” weekly seminar.
The upper-basin states are at most risk because their uses of water would have to be curtailed to meet requirements of downstream states, Kuhn said.
In the future, “We’re going to be stressing major reservoirs” as they are emptied to meet downstream needs, he said.
Worse, the compact makes no provision for a simple lack of water, Kuhn said, leaving the upper basin on the hook to deliver, no matter whether there was enough runoff to meet the requirement.
That’s because the framers of the original compact based the allocation of water on what had been a high-flow series of years, Kuhn said. That led to the optimistic plan to reconsider the compact in 1962, when the states would better know how to divide up the surplus water they anticipated would be better understood over the next four decades.
That meeting never took place as it slowly became clear that the Colorado River historically carried less, not more, water than had been assumed.
A study by the U.S. Bureau Of Reclamation to be released next month will make it clear that even under the 20th century understanding of hydrology, “The demands on the Colorado River exceed its supplies,” Kuhn said.
The fact that the lower-basin states are using less water and upper-basin states using more will have political implications, he said.
In the meantime, however, changing climate, receding waters in the Colorado and other changes could lead officials to re-evaluate some assumptions about the way the river should be managed, Kuhn said, noting that a 1944 agreement on the river introduced the phrase “extraordinary drought” without defining it.
It might be that such a circumstance is more dire than even today’s conditions, Kuhn suggested.
“If the future is going down (as in the level of the river) then is that a new drought?” he asked, “Or is that a new normal?”