DisastersWestern states could face disastrous floods from record snowpacks

Published 26 May 2011

Western states could soon face disastrous floods like the Midwest due to record snowpacks; heavy winter storms and an abnormally cold and wet spring have resulted in record snow levels for May in states across the west including Montano, New Mexico, Colorado, and California; officials worry that if June is particularly hot and sunny, the snow could melt too quickly and inundate the region’s rivers with torrents of water; officials are particularly concerned about flash floods as they can occur with little warning; officials are bracing for the worst holding emergency drills and releasing thousands of gallons of water to make room in reservoirs
Western states could soon face disastrous floods like the Midwest due to record snowpacks

Heavy winter storms and an abnormally cold and wet spring have resulted in record snow levels for May in states across the west including Montano, New Mexico, Colorado, and California.

Officials worry that if June is particularly hot and sunny, the snow could melt too quickly and inundate the region’s rivers with torrents of water. However, if the weather conditions are milder, the snow would melt more slowly and there is a chance that disaster could be averted.

Bob Struble, the director of emergency management for Routt County, Colorado, said, “All we can do is watch and wait.”
“This could be a year to remember,” he added.

Routt County’s watershed currently has more than seventeen feet of snow in parts of its watershed and Steamboat Springs, the county’s largest city, is located thirty miles away from the Yampa River, a major tributary of the Colorado River.

Disaster planners are particularly concerned about flash floods as they can occur with little warning. In 1976, more than 140 people were killed in Big Thompson Canyon, Colorado when a sudden rush of water appeared.

According to the National Weather Service, on average more people are killed each year by floods than tornadoes, lightning, or hurricanes.

Arthur Hinojosa, the chief of the Hydrology and Flood Operations Office at the California Department of Water Resources, explained, “It just takes one really sunny hot spell to get things running, and that’s where our concern lies.”

The last time record snowpacks caused widespread flooding across the west was 1983, but since then communities have moved into once deserted floodplains, putting them at great risk this year.

These communities have bolstered flood defenses, but these measures have never been tested.

In addition, unlike the Mississippi River, which is largely a single waterway, the west is comprised of a complex series of smaller waterways that wind its way across hundreds of communities.

It is impossible to tell which of the hundreds of waterways will surge if at all. As a result, authorities across the west are bracing for the worst.

Last week, officials in California held three days of flood training, playing out various disaster scenarios and even practiced filling sandbags. Officials there are particularly worried that millions of gallons of melting snow could rupture the aging levee system holding back the Sacramento and San Joaquin River Delta, resulting in a Hurricane Katrina-scale flood.

Meanwhile federal authorities at Fleming Gorge Reservoir in Utah made the decision to spill 700,000 acre feet of water downstream to make room for additional water. Officials expect at least 1.4 million acre feet of water through July.

While the large snowmelt could spell disaster for many communities, it has also brought much needed drought relief to the Colorado River, which provides nearly thirty million people in seven states with drinking water as well as millions of acres with irrigation water for crops and pastures.

The region’s two main sources of water Lake Mead and Lake Powell have suffered from nearly a decade long drought and the water level has dropped to record lows at both sites. The snows will likely add 1.5 trillion gallons of additional water to dwindling water supplies.

Some areas like the Wasatch Mountains, outside Salt Lake City, Utah, are actually still receiving more snow. Last week the region received three additional feet, and hydrologists warn that the cold temperatures are keeping snowpacks from reaching the isothermal barrier, 32° Fahrenheit throughout the snowmass, which would allow for gradual melting from the bottom.

For now, local, state, and federal authorities have no other choice but to keep a close eye on the weather and continue to make preparations for what could be a disastrous summer in the west.

view counter
view counter