Even a below-average rainy season can have a few intense storms that trigger debris flows, officials said.
"You shouldn't let your guard down," said Steven Sheridan, assistant division engineer for county water resources. "From where we stand, that doesn't mean much."
Sheridan briefed residents on the expansion of several local debris basins and repairs to other county facilities meant to direct water and debris away from homes.
Capacity at the Pickens debris basin was expanded from 125,000 cubic yards to 156,000, he said. The Pinelawn basin's capacity was expanded from 3,200 cubic yards to 4,800, and the Starfall basin 15,000 cubic yards to 28,000.
Cement barriers, or K-rails, will also be in place, Sheridan said.
Los Angeles County Sheriff Capt. David Silversparre also outlined updated evacuation protocols in response to some complaints last year.
The new four-color coded system is aimed at increased flexibility, Silversparre said, adding that officials still want residents to heed mandatory orders if they are called.
"Prediction is not an exact science," he said. "But we do implore you to evacuate when we ask you to go."
For updated information throughout the winter rain season, visit the county's Coordinated Agency Recovery Effort website at http://dpw.lacounty.gov/care/.
Infobox
2010-11 Foothill Incident Unified Command evacuation protocols for debris flow events:
Green level
- No evacuation orders or rain-related parking restrictions in effect, unrestricted entry to impact areas.
Yellow level
- No evacuation orders in effect
- Rain-related parking restrictions in effect
- Residents encouraged to remove vehicles, trash bins and other obstructions from the streets
Orange level
- Evacuation orders in effect
- Residents electing not to evacuate will be asked to sign a waiver form assuming all liability for remaining
- Residents who evacuate but wish to return to their homes can gain re-entry at the discretion of sheriff's officials by signing a waiver form
Red level
- Mandatory evacuation orders in effect
- Residents electing not to evacuate will be asked to sign a waiver form assuming all liability for remaining
- Entry into the area shall be prohibited to all but public safety responders
- Residents will not be allowed to return to their homes as long as the red level remains in effect
