By Mary O’KEEFE
The Crescenta Valley Town Council meeting on Oct. 15 included a presentation by Chris Stone of the Dept. of Public Works Los Angeles County.
“We are taking El Niño very seriously,” Stone told the audience.
El Niño is the heating of ocean water around the equator, which simultaneously creates a high-pressure system that changes the path of the jet stream (the flow of winds that direct storms) and pumps more evaporated water into the atmosphere, condensing as huge storm clouds. It both creates and drives huge storms to our area.
The NWS classification system for El Niño rates the severity based on the temperature increase. From 0.5 to 0.9 C above normal is considered a weak El Niño. From 1.0 to 1.4 C above normal is a moderate El Niño, and 1.5 C and above is considered a strong El Niño. With an expectation of 2.0 or above, this El Niño year could bring quite a bit of rain, which California is sorely in need of during its severe drought.
“El Niño is not a storm; it is a condition,” Stone said. “There is a 95% chance this [El Niño] is going to be very strong throughout the winter.”
Historically, there have been six strong El Niños with two of those six events doubling the rainfall in downtown Los Angeles, Stone said. During the last large El Niño condition in 1998, over the course of a month L.A. was hit with four large storms and two small ones that dumped almost an entire year’s worth of expected rainfall.
The majority of the upcoming El Niño rain is expected in January and February before tapering off, Stone said.
“If you look at El Niño weather patterns it is interesting that a strong El Niño event [one year] is followed by a very dry year,” Stone said.
The DPW is planning ahead by preparing road and flood control facilities and cleaning out and removing debris from culverts and catch basins. They have regular meetings with the National Weather Service, the U.S. Army Core of Engineers and the California Dept. of Water Resources Flood Coordination. Community meetings are held for residents living in and near hillside burn areas.
There are miles of roads and debris basins that need to be prepared in anticipation of the arrival of the El Niño. Additionally, DWP owns and operates 14 dams in the L.A. County that must be maintained.
But the community must be prepared as well, Stone said.
“We encourage residents to know their individual flood risk … and areas with historical drainage issues,” he added.