SAN FRANCISCO (KRON) — The Federal Emergency Management Agency has published a 66-page report outlining response plans to the potential devastation resulting from what weather experts are forecasting as the largest El Niño system in history.

El Niño-related storms are expected to dump heavy rain over much of the southwest this winter, bringing the threat of widespread flooding, mudslides, above normal snow levels, and strong winds, and power outages, according to the guide.

“We ask Californians, Arizona, Nevada and Hawaii and the Pacific Trust Territories to get ready for above average El Niño conditions this winter, and remain prepared throughout the season for floods, continued drought and wildfire risks, and any other extreme weather it might bring,” officials said in an email.

FEMA’s Disaster Response Plan consists of three phases and addresses the possible need for power outages, evacuations, temporary shelters, food and water requirements, and medical shelters for Region IX which covers the southwest.

In planning its response, NOAA scientists suggested using a potential model based on information from the 1982-83 El Niño season, which recorded 36 storm-related deaths and 481 injured, the report said.

“In one 36-hour period, 25 inches of rain fell in the Santa Cruz (coastal) mountains while 8.5 feet of snow fell in the Lake Tahoe region. Forty-six counties were disaster-declared,” the report said.

The economic impact to the state caused by 1982-83’s El Niño was also costly. California reported an estimated $1.209 billion economic losses including 6,661 homes and 1,330 businesses damaged or destroyed, according to the report.

The storms that followed the 1982 El Niño jammed SoCal freeways, flooded neighborhoods, knocked down trees and power lines, damaged homes, caused mudslides and even generated a tornado in South Los Angeles (L.A.). More than 31 inches fell in L.A. during the 1982-83 rain year.

Also on the list of FEMA’s critical considerations for this year’s storm season are debris flows, especially in areas that were damaged during the summer’s wildfires such as Lake County, and transportation.

“Flooding and landslides will disrupt surface transportation networks. Ports, major highways, and railroads will be affected. Heavy rainfall, flooding, and snow, and landslides will affect roads going into the Sierras and limit evacuations to the east,” the report says.

THREAT TO BURN SCAR AREAS, LOW-LYING CITIES

The report says that currently, one in five Californians live in a flood risk zone. “All 58 counties in California have experienced at least one major flood event in the last 20 years,” the report warns.

“There is substantial risk in Northern California (NorCal) due to potential levee failures,” the report says. “The Sacramento-San Joaquin Delta is particularly vulnerable to levee failures due to its location, aging infrastructure, low elevation, and subsidence.”

Debris flows are also a concern, especially in towns ravaged by wildfires, putting stress on recovery efforts. “Debris flows, or mudslides, and landslides will be common in burn scar areas,” the report says.

In 1982, El Niño storms caused extensive flooding, landslides, coastal erosion, and damage to coastal structures.

“Based on average sea level data obtained from the California Climate Change Policy Advisor, scientists indicate California will likely experience rising sea-levels this winter caused by the warmer water seen with El Niño seasons. These elevated water levels will be the base, on top of which additional high water levels will occur due to storms,” the report said.

The City of Oakland, which is among the many low-lying cities surrounding the San Francisco Bay, is urging residents to prepare for flooding.

“During big storm events, our crews and emergency personnel will be working around the clock, but they – along with crews around the region – may be overwhelmed, so you should plan ahead to have the supplies you would need in any emergency,” the city said in an email.

NO RELIEF FOR CALIFORNIA DROUGHT

It’s unclear how much rain Northern California will receive this season, but current predictions point to a higher percentage of southern storm tracks showering Southern California with more rain volume. Regardless of the quantity, FEMA says it won’t be enough to relieve the dry state from its record-breaking drought.

“Precipitation in California will fall more as rain, leading to less water stored in the snow pack. This does little to alleviate the drought, especially with an increase to southern storm tracks,” the report said.

Preparedness Tips

The City of Oakland issued the following preparation steps for lessening the impact of weather emergencies. Follow these simple steps:

• Clear your gutters and downspouts; ensure downspouts are working and draining away from your house

• Keep your curbs and sidewalk gutters clear of leaves and debris

• Check the storm drains near your house and use a rake to keep them clear of debris

• Trim trees to help them handle strong winds and rain; call a certified arborist to inspect your trees if you have concerns about unusual leaning or dead branches

• Take a look at your property and make any needed repairs

• Check out your local hardware store for home flood prevention tools and techniques for using sandbags to divert water away from your property or prevent it from coming in through doors and basement windows

• Review your property insurance; if you don’t have flood insurance, consider getting it now – it takes 30 days to take effect

• Know the emergency procedures and evacuation plans at your children’s schools

• Make sure you have emergency supplies to last for at least three days, including enough water, food, medicine and other supplies for family members and petsIMAGE: California is affected by many types of flooding. SOURCE: FEMA