As two powerful storms headed for Southern California, putting residents along eastside foothills and burn areas on notice, Los Angeles area officials began preparing Wednesday for what is expected to be the most rain in the area in several years.

Crews cleared out debris basins, sandbags were placed at the ready and crews were braced for the possibility of floods and mudslides from the storms, expected to drop up to 4 inches of water on the region.

While the rain is a welcome relief from the drought, experts agree it will take far more than the back-to-back storms to make up for the dry years of the past decade.

“The fact is we have some catching up to do, and we are not going to catch up this year,” Metropolitan Water District spokesman Bob Muir said. “These storms will help replenish the groundwater basins some, but it will not replace what we need from Northern California.”

Still, Los Angeles should be ready. The Emergency Management Department is mounting its first stage of readiness, coordinating the metropolitan area’s plans in terms of power, road closures, shelters and the need for sand and sandbags.

One of the biggest concerns is the Sepulveda Basin, built in 1941 by the U.S. Army Corps of Engineers as a flood-control area. Police will shut off traffic through Burbank Boulevard as soon as they believe it is necessary to avoid motorists being trapped or endangered as the waters flow through.

At Hansen Dam, crews had cleaned all catch basins in the stormwater collection system, and the Los Angeles Fire Department put its swiftwater rescue teams on alert.

Sanitation crews dredged and cleaned city debris basins, and L.A. activated its storm-watch response teams to round-the-clock service beginning Wednesday.

“We ask our residents to avoid flooded intersections in low-lying areas and rushing waters in the foothills and to abide by all street closure and warning signs,” said Jimmy Tokeshi, spokesman for the Department of Public Works, adding people should call 800-773-2489 or 3-1-1 to report clogged catch basins or debris.

The Bureau of Street Services has crews on patrol to remove fallen trees, limbs or other obstructions.

In addition, free sand and sandbags were being made available; L.A. residents can call 3-1-1 to find a location near their house. Burbank city officials said they would offer them at its Field Services Yard, 124 S. Lake St.

Officials at the Department of Water and Power issued warnings on the potential danger from downed power lines and had some advice for those wishing to capture the rainwater.

“Rain barrels are best for capturing rain and diverting downspouts from gutters to your garden area, away from sidewalks,” spokesman Joe Ramallo said.

On the power lines, David Wiggs, senior assistant general manager for power, said the concern is that poles and lines can be knocked down by a storm, especially with the high winds expected this week.

“With the lack of significant rain this season, there may be more dead branches or debris that can potentially fall on power lines,” Wiggs said, adding the public should remain clear of any downed power line and call 911 or 800-DIALDWP. (342-5397)

“If a power line falls on your car, stay in the car and wait for help. If you need to get out, make sure you do not touch any metal parts of the car or the ground at the same time.”

Wiggs recommended having working flashlights with extra batteries at the ready. If power goes out, turn off and unplug all appliances with the exception of one light to determine when power is restored.

He urged Angelenos to review plans with their families to make sure they have contact information and know where to meet in the event of an emergency.

Mayor Eric Garcetti reminded residents to turn off their sprinklers during the storm and to take other steps to conserve water by going to the DWP’s website at ladwp.com.