On the one-year anniversary of the devastating hurricane that flooded the Gulf Coast, Bakersfield authorities are out with new evacuation plans for local residents.

The new plan lists risks from Isabella Dam as the prime threat. As Eyewitness News was first to un-cover, the Corps of Engineers has new concerns about the dam and lists it as their most at-risk in the nation.

The evacuation plan from the Bakersfield Police Department notes the dam is built near a major earthquake fault, and if it failed up to a half-million people could be affected. Engineering maps show much of Bakersfield could end up flooded -- if the dam failed when Isabella Lake was full.

The Corps of Engineers has ordered the water level in the lake lowered as a precaution, but the evaucation plan is ready so residents can be prepared even in a worst-case situation.

"I think we have to be honest, it's going to be pandamonium if there's warning of an impending flood," Assistant Chief Bryan Lynn told Eyewitness News.

Lynn says first off, the new plan improves methods for telling residents if they need to evacuate. He says the previous plans called for officers driving through neighborhoods with bullhorns.

The new plan uses the "reverse 911" system to automatically alert areas of town, the media will be notified, and the Citizen Volunteer Corps and Neighborhood Watch groups will also be used.

Police say officers with bullhorns might still go through neighborhoods if an evacuation order went out in the middle of the night. Police believe there will be at least five hours before water would reach Bakersfield.

The plan divides the city into four quadrants and lists evacuation routes and directions. It's believed much of northeast Bakersfield would remain above water, and that's where eight different schools would be used as evacuation shelters.

In other areas, residents may need to move to higher ground. Residents in northwest Bakersfield would need to go north and west. The recommended routes include north on Highway 99, Allen Road and I-5. Or residents could go west on Rosedale, Stockdale or Seventh Standard.

Some areas of northeast Bakersfield might be cut off during flooding. The plan recommends those residents head east on Highway 58, Breckenridge or Edison. They could also go south on Comanche or Morning Drive.

Southwest Bakersfield residents would probably get the most warning and see the least flooding. The plan says some people could probably safely stay in their homes.

For other southwest residents, the recommended evacuation routes are west on Stockdale, Panama Lane, or Taft HIghway. Or going south on I-5, Highway 99, Old River, Gosford, Stine, Wible or Buena Vista Road.

The report says southeast Bakersfield residents may not have to go far to reach safety. The recommended routes are south on 99, South Union, Fairfax or Weedpatch. Or going east on Highway 58, Edison Highway, Panama Lane or Panama Road.

The large evacuation plan also lists of hundreds of facilities that may have special evacuation needs. These includes hospitals, schools, day-care centers and nursing homes. Chief Lynn says these facilities will get evacuation information.

The police department plans to put the evacuation report on their web-site within the week. That web address is www.Bakersfield PD.us. In a couple months, the department will also have pamphlets explaining the evacuation plan available at schools and library branches.

The new evacuation plan also includes more emergency preparation information and other useful websites. And it describes instructions for what to do if you are ordered to evacuate.

That includes wearing long-sleeved shirts and pants and sturdy shoes. Families should take along a disaster kit, and take along any pets. However, police say pets are not allowed in public shelters -- families with pets should arrange to stay with a relative or friend or find a "pet friendly" hotel.

The plan also tells families to lock their homes before evacuating, and then stay away from downed power lines -- and to stick to only recommended travel routes.

Emergency planners say it's important for families to look over the recommended evaucation routes from their home or place of business.

"We want people to mentally rehearse -- OK if I have to leave my home, where am I going to go in the middle of the night? I need to be somewhat familiar with names of roads and these routes," says Lynn.