Snowfall giving Lake Mead a lift
August 7, 2011 - 12:59 am
After a decade of drought and disappointment, the Colorado River is suddenly doing something it hasn't done in a while: exceeding expectations.
In a good way.
What was already shaping up to be a wet year on the river is quickly approaching record territory, thanks to a huge influx of snowmelt and rainwater in July that even surprised federal forecasters.
The river system that fills Lake Mead and supplies 90 percent of Las Vegas' drinking water is on track for its third wettest year since Lake Powell was filled for the first time in 1963.
The rising runoff total could mean even more water for Lake Mead, which is already expecting its biggest boost by far since 1998.
Snowpack expert Randy Julander chalked up this summer's massive flows on the Colorado to a near-perfect combination of heavy snow, unseasonably cool weather and above-average rainfall in the mountains that feed the river.
"It has been a phenomenally good year for reservoirs and for Lake Powell in particular," said Julander, who supervises the federal snow survey program in Nevada, Utah and California for the U.S. Department of Agriculture. "One good year like this one goes a long way toward fishing us out of the toilet."
Already, the surface of Lake Powell has risen to its highest level in a decade, while Lake Mead is back to where it was in early 2009.
The surface of Lake Mead is now 20 feet higher than it was a year ago, and current projections -- ones now likely to be adjusted upward -- call for it to rise another 33 feet by Aug. 1, 2012.
"We're just tickled to death to see the rebound," Julander said. "Any time you get this kind of water and you're able to store a good chunk of it, it's good for everyone."
A LAST-MINUTE REPRIEVE
Last month's inflow ranked as the second largest Lake Powell has ever seen in July. The 4.35 million acre-feet of water that poured into the reservoir on the Utah-Arizona border that month was almost three times the July average, and the flow in June was even greater -- 5.4 million acre-feet, or almost 24 times the amount of water used in the Las Vegas Valley all of last year.
One acre-foot equals about 326,000 gallons, which is enough water to supply two average valley homes for one year.
A huge year on the river couldn't have come at a better time for Lake Mead.
On Nov. 27, the nation's largest man-made reservoir shrank to its lowest level since it was filled in the late 1930s.
Had it fallen another 7 feet, Nevada and Arizona would have faced federally mandated shortages. Had it fallen 32 feet, the Southern Nevada Water Authority would have lost the use of one of two intake pipes used to supply the valley with nearly all of its drinking water.
In that respect, this year's near-record runoff is "absolutely critical," but it doesn't mean the drought is over, according to John Entsminger, deputy general manager for the water authority.
Even with the additional water, Lake Mead is expected to finish the year at about 56 percent of capacity.
"Whether it's half-full or half-empty is a matter of perspective. As water managers, you have to assume the worst-case scenario," Entsminger said. "We're not ready to say we're out of the woods just yet. The lake can drop as fast as it can come back up."
BETTER FOR BOATERS
Marina operators at Lake Mead take a sunnier view.
"It's great news. It just keeps going up and up and up," said Kim Roundtree, general manager of Callville Bay Resort and Marina.
The rising water will create more room for the marina and more open water around it. Roundtree said the marina plans to reconfigure its operation starting in October to account for the changing conditions.
Gail Gripentog Kaiser said the water is already coming up fast at Las Vegas Boat Harbor, the marina she manages and part-owns down the hill from Boulder City.
In the span of six days last week, the lake rose a foot and the shoreline shifted some 20 feet at the marina, Gripentog Kaiser said. By the end of the year, she expects the lake to push up the hill to where the pavement ends on the road leading down to Las Vegas Boat Harbor.
"We won't have to drive to work on a dirt road anymore," she said.
And while the lake's rise will mean a lot of work for her personally, Gripentog Kaiser said it sure beats the alternative.
"It's really good news for the lake. It's good news for Las Vegas. It's good news for the entire Southwest. Everybody uses water from Lake Mead," she said.
Boaters, meanwhile, are benefiting from easier access to the lake.
Within the last few months, the rising waters have allowed the National Park Service to reopen the old boat-launch ramp at Callville Bay and the ramp at the new and improved Boulder Harbor.
But Gripentog Kaiser offered a word of caution: The lake is constantly changing, so boaters should treat every visit like their first.
"What was an island last week is a sandbar today," she said.
SNOW AND MORE SNOW
The runoff into Lake Powell is now starting to slow, but it is by no means over.
Malcolm Wilson from the U.S. Bureau of Reclamation's upper Colorado River regional office in Salt Lake City said some snow is "still hanging" at several mountain survey sites, which is very unusual for this time of year.
It has led to speculation that the melt might never come to the northern reaches of the river basin. With summer half-over and temperatures due to start falling again soon in the high country, Wilson said snow now on the ground could linger into next year.
In Utah alone, record amounts of snow piled up at roughly two dozen survey sites that have been in use for at least 30 years, and 21 streams saw the highest flows ever measured. "Some of those (stream gauges) go back 106 years," Julander said.
Throughout June and July, he said, Glen Canyon Dam in Arizona released water downstream as quickly as its available power generators would allow, but Lake Powell still continued to rise by about a foot a day.
The challenge in a year like this is to find a way to store as much water as possible while minimizing flooding.
"That's always a good problem to have," Julander said. "When water's life, having an abundance of it is a good thing for everyone."
Contact reporter Henry Brean at hbrean@reviewjournal.com or 702-383-0350.