By Jason KUROSU
Significant rainfall is expected to hit Southern California this winter, with an El Niño event that should bring higher than average rainfall to the area, though not enough to quell the state’s historic drought.
An advisory released last week by the National Oceanic and Atmospheric Administration concluded that there is a 95% chance that El Niño will continue through the winter months in the Northern Hemisphere before waning sometime in spring 2016.
Tom Di Liberto, a meteorologist with NOAA’s Climate Prediction Center, said that current sea surface temperatures of two degrees Celsius above average and weakening easterly trade winds denote a strong El Niño event.
Above average precipitation is expected in Southern California, while temperatures should rise in northern California.
Despite the imminent rainfall this winter, the rains are not expected to make a significant dent in the state’s persistent drought conditions.
During a Sep. 10 NOAA teleconference on El Niño, NOAA Deputy Director Mike Halpert said, “One season of above normal rain and snow is unlikely to erase four years of drought.”
Di Liberto said that increases in rain and snow would also not necessarily replenish the diminished snowpack, which hit historic low levels this year.
“An increase in precipitation doesn’t mean it’s going to snow where it needs to,” said Di Liberto.
Di Liberto added that comparisons to the 1997-98 El Niño event, which set precipitation records in 19 cities across the state and caused over $550 million in damages due to flooding, are difficult to make.
However, local city, county and transportation organizations are preparing for the incoming rains.
Rainfall flooded three lanes of the eastbound 210 Freeway last week near Ocean View Boulevard. Caltrans crews pumped out water that pooled during Tuesday afternoon’s rains, closing down lanes for a few hours.
Two projects are currently underway to rehab sections of the 210 Freeway, including a pavement and slab replacement project that includes an upgrading of the freeway’s drainage system, which would replace drainage infrastructure and bring the system up to current Caltrans standards. The $148.5 million project is slated for completion in mid-2018, but Caltrans District 7 Staff Service Analyst Jacqueline Beaver said the upgrades to the drainage system should be completed by January 2016.
Mudslides and other debris flows are a concern for officials and residents, particularly with Southern Californian hillsides stripped of flow obstructing vegetation due to the excessive drought and wildfires.
Glendale Public Works Director Roubik Golanian said he is concerned about “recent fire burn areas that have not seen sufficient vegetation growths due to years of drought conditions” and that the city will “look for susceptible mudslide sites and any blockage within the natural and historical drainage paths to the debris basins.”
Golanian said the city manager, fire, water and power, and public works departments have begun strategizing in preparation for El Niño.
“We have already sent letters to the property owners that have construction projects underway to put in place erosion control measures for the protection of slopes and excavated sites. We have started cleaning our few debris basins and working closely with the County Flood Control District to make sure their debris basins are all cleaned up as well,” said Golanian.
Tom Lorenz, Glendale director of Communications and Community Relations, recommended that residents take advantage of resources put forth by the city including signing up for the city’s Emergency Notification System and the City Connection newsletter, which will feature tips on dealing with heavy rains and potential flooding and mudflows.
Free sandbags will be distributed in the coming weeks at certain locations and a city operational plan will also be released, Lorenz said, detailing measures for residents and businesses for dealing with potential flood conditions.
The Los Angeles County Public Works Dept. said that county debris basins, pump stations and well sites are storm ready.
According to Kerjon Lee, Public Affairs manager for L.A. County Public Works, “The County’s debris basins are already at their desired capacity for storm season, so there’s no need to remove more sediment. Public Works crews are busy mowing the basins and removing leaves and other foliage from drain outlets so that stormwater can move effectively through the system.”
An L.A. County El Niño Preparedness Report states that 32 potentially storm vulnerable water reservoir sites are in need of repair, but that those repairs should be completed prior to the storm season.
The report also said that county projects to increase dam operational reliability and stormwater capture have bolstered the flood control system’s operational readiness.
Plans for sediment removal at several county reservoir sites were already made, including at Devil’s Gate Dam, which filled with debris during the 2009 Station Fire. The report states that preventative measures have been taken at Devil’s Gate, including the installation of steel trash racks to keep flood protection valves from plugging, boom logs to block floating debris and maintenance platforms to keep spillways clear.
Lee also recommended residents visit the county’s Coordinated Agency Response Effort website at dpwcare.org, where resources can be found for El Niño preparation.