A proposal to give Colorado and other upper-basin states that use the Colorado River more flexibility during droughts can be traced back to 2002 when the waters of Lake Powell were dwindling.
“Lake Powell in 2002 was literally within a couple of years of going dry,” said James Lochhead, an Aspen attorney who represents several Colorado water districts and users.
That scenario could have led to disaster for the four upper-basin states that use the river’s waters – Colorado, Utah, New Mexico and Wyoming.
Under the Colorado River Compact, lower-basin states – California, Nevada and Arizona – could issue a basin call, shutting off water rights in the upper basin awarded after 1922.
That would have meant the Western Slope, Denver, Aurora and Colorado Springs would have seen their use of the basin go dry.
Seeing the looming problem, then- Interior Secretary Gale Norton in 2002 told the seven states that rely on the Colorado River to draw up a set of shortage measures to help manage the water during drought.
Norton set deadlines for an agreement and said she would impose her own plan if those deadlines were not met.
“We’ve been working on it ever since,” Lochhead said.
On April 30, the seven states that use the Colorado River signed an agreement.
The proposal is being reviewed by Interior Secretary Dirk Kempthorne.
The plan permits upper-basin states to release less water to lower-basin states during a drought and when less-than-average snowpack accumulates on the Rocky Mountains’ western slopes.
The agreement enables lower-basin states to look elsewhere for water supplies, said Scott Balcomb, Colorado’s commissioner to the Upper Colorado River Commission.
It also sets a framework in which Lake Mead and Lake Powell would operate in conjunction to ensure the dams have enough storage.
“This may be the first time that the seven states in the Colorado River Basin have come together,” said Chris Treese of the Colorado River District.
The proposal updates the 1922 Colorado River Compact.
The compact sets rules for states using the river, which flows from Rocky Mountain National Park through the Grand Canyon and disappears in the Sonoran Desert before reaching the Gulf of California.
Under the 85-year-old compact, states are divided into two basins.
The lower-basin states and Mexico, under a different treaty, get a guaranteed amount every year – a total of 8.23 million acre-feet. The upper basin divvies up the remainder.
The 1922 compact was drawn up assuming 17.5 million acre feet of water were in the river every year. But between 2000 and 2005, the river averaged a total of approximately 9.62 million acre-feet.
An acre-foot is almost 326,000 gallons, enough water to supply two families of four for a year, according to water authorities.
Lake Powell serves as a type of savings bank for water for the upper basin – catching river water before releasing the required amount to the lower basin.
“Lake Powell is our protection against a compact call,” Treese said. “When Lake Powell is low, it increases a risk of a compact call.”
The lake reached its lowest level in April 2005, when it was 33 percent of capacity.
Since then, the region has had snowy winters and wet springs but is still in the grips of a drought.
In other Colorado basins, the South Platte River is below average this year, and the Arkansas River is above average, Treese said.
Staff writer Jeremy P. Meyer can be reached at 303-954-1367 or jpmeyer@denverpost.com.
