Wet El Niño winter expected to raise reservoir water levels
PHOENIX - A wet El Niño winter is expected to raise water levels in Arizona reservoirs.
An El Niño season is caused every couple of years by water warming in the Pacific Ocean, bringing rain to the Southwest, the Arizona Republic reported.
Salt River Project Water Resource Operations Manager Charlie Ester said since World War II, Arizona has had wet winters in every El Niño year.
"We have had normal winters (during an El Niño year)," he said. "But after the last five years, even a normal winter would be wonderful."
Ester said he hopes the rain will help put water back in reservoirs along the Salt and Verde rivers, which combine with the Colorado River to provide a third of what residents use statewide.
The El Niño winter in 2010 was considered "moderate" and filled SRP reservoirs. This El Niño year is expected to be very strong, with a 90 percent chance of lasting through winter and ending in 2016.
"With the stronger El Niño , there is a stronger likelihood for wetter conditions," National Weather Service meteorologist Ken Daniel said.
Normal November-April snowfall for the Prescott area is almost 13 inches. In strong El Niño years, it increases to nearly 20 inches. Total precipitation in increases to almost 13 inches in strong El Niño years compared to less than 9 inches normally.
The last year of a strong El Niño was 2009-10. For Prescott, that meant flooding, including $15,000 in damage to Skyview School in a storm Dec. 7-8, 2009. Wind gusts in that storm reached 75 mph and more than 5,000 homes lost power.
Heavy rain and snow melt a month later, caused record flooding in Black Canyon City, destroying 150 homes. That same winter, 5-20 inches of snowfall across Oak Creek and Sycamore Canyon soaked the ground and caused a section of state Highway 89A to give way.
State climatologist Nancy Selover said snow, more so than rain, is a drought deterrent.
"What we would ideally like is a good soaking rain before we get our first snowfall," Selover said. "So the soil gets wet, then we have our snowpack on top of that. If we keep the snowpack all winter, when it starts to melt, the soil underneath it is already wet, so we don't end up with that moisture all soaking into the soil. We could get some really good runoff."
Rain or snow, Ester said it would take more than one El Niño season to stymie 20 years of drought conditions in the Southwest.
"At this point, after 20 years of drought, I will take it in any form it comes," Ester said. "Even if it dropped out of the sky in gallon bottles, I'd take it."
Daily Courier reporter Les Bowen contributed to this story.