Scientists: Biggest reservoirs trending right direction
ALBUQUERQUE, N.M. » Parts of California are under water, the Rocky Mountains are bracing for more snow, flood warnings are in place in Nevada, and water is being released from some Arizona reservoirs to make room for an expected bountiful spring runoff.
All the moisture has helped alleviate dry conditions in many parts of the western U.S. Even major reservoirs on the Colorado River are trending in the right direction.
But climate experts caution that the favorable drought maps represent only a blip on the radar if the long-term effects of a stubborn drought persist.
Groundwater and reservoir storage levels — which take much longer to bounce back — remain at historic lows. The record database in most cases is about 50 years or so.
It could be more than a year before the extra moisture has an effect on the shoreline at Lake Mead on the Arizona-Nevada line. And it’s unlikely that water managers will have enough wiggle room to wind back the clock on proposals for limiting water use.
That’s because water release and retention operations for the reservoir and its upstream sibling — Lake Powell on the UtahArizona line — already are set for the year. The reservoirs are used to manage Colorado River water deliveries to 40 million people in seven U.S. states and Mexico.
Still, Lake Powell could gain 45 feet as snow melts and makes its way into tributaries and rivers over the next three months. How much it rises will depend on soil moisture levels, future precipitation, temperatures and evaporation
losses.
“We’re definitely going in the right direction, but we still have a long way to go,” said Paul Miller, a hydrologist with the National
Weather Service’s Colorado Basin River Forecast Center.
California already has been drenched by a fire hose of moisture from the Pacific Ocean that has led to flooding, landslides and toppled trees.
Ski resorts on the CaliforniaNevada line are marking their snowiest winter stretch since 1971, when record-keeping began. In fact, the Sierra Nevada is on the verge of surpassing the second-highest snow total for an entire winter season, with at least two months still to go.
In Arizona, forecasters warned that heavy rain was expected to fall on primed snowpack in the mountains above the desert enclave of Sedona. One of the main creeks running through the tourist town was expected to reach the flood stage and evacuations were ordered for some neighborhoods.
“We’ve pretty much blown past all kinds of averages and normals in the Lower Colorado Basin,” Miller said, not unlike other western basins.