Imagine Salt Creek on aqua-steroids — banks overflowing — waters reaching from the west side of downtown to the east side of Capitol Beach Lake.

That’s a hundred-year flood.

And its the likeliest big natural threat to Lincoln in terms of large-scale property damage, said Doug Ahlberg, Lancaster County emergency management director.

The risk of a large flood is even greater than that of a tornado.

Such a flood could put areas up to eight blocks away from Salt Creek under six feet of water. Salt Creek runs through Lincoln from the southwest to the northeast.

Floodwaters could reach the northern and western edges of the University of Nebraska-Lincoln City Campus, surround Oak Lake, swamp parts of the State Fair grounds and flood other neighborhoods and businesses.

Don’t be overly alarmed.

Lincoln doesn’t share the topographic and geographic perils of New Orleans, swallowed by Hurricane Katrina more than two weeks ago.

Nor have the dangers of flooding in Lincoln been ignored.

In the last half-century, Lancaster County’s flood dangers have been reduced by work on the Salt Valley Lakes and the creeks that run through Lincoln.

The county also has step-by-step plans to handle flooding and other disasters, natural or manmade, Ahlberg said.

“Nobody is prepared for an event,” he said. “But are you prepared to respond to an event? I think we are.”

Still, state officials already are looking for lessons learned from Hurricane Katrina.

Response to county disasters begins with the LEOP (Local Emergency Operations Plan).

That plan details how local officials should respond to a wide range of disasters. It’s four inches thick and is updated every year.

In the case of extensive Salt-Creek flooding, officials could call for the voluntary evacuation of areas in the creek’s 100-year floodplain. In cooperation with the American Red Cross, evacuees would be housed in designated shelters — just as people were housed in Pershing Auditorium after the October 1997 snow storm paralyzed the city for nearly a week.

Shelter locations and evacuation routes could be distributed by the media hours before flooding began, Ahlberg said.

Also, the Lancaster County Emergency Management Agency has a Lincoln Area Agency on Aging database that identifies people who need assistance leaving their homes, he said.

There is no such database identifying people who don’t own cars. But people without individual transportation could walk to identified assembly areas, where buses would take them to the shelters, Ahlberg said.

Lincoln has significant resources — more than most similar-sized communities — to deal with a variety of disasters, said Deputy Fire Chief Dean Staberg, who has done peer assessments of emergency response plans in cities across the country.

“We’ve got a lot of available resources as far as trained personnel and equipment,” Staberg said.

Lincoln is one of 28 communities nationwide to have a federally funded Urban Search and Rescue team, run by Lincoln Fire & Rescue. The next-closest team is in Missouri.

In the event of a tornado or terrorist bombing, the 180-member team has experience and equipment to conduct rescue missions involving the breaking down of heavy walls.

Lincoln Fire & Rescue can be almost anywhere in the city in five minutes.

The county also has a sophisticated and efficient communications system, Staberg said.

Lincoln firefighters, police, Lancaster County Sheriff’s deputies, University of Nebraska-Lincoln police, rural fire departments and city and county officials can talk to one another using the same radio system.

That’s in contrast to the Sept. 11, 2001, New York City terrorist attacks, during which firefighters couldn’t even talk to police, Staberg said.

Lancaster County also has a back-up 911 center, 11 Community Emergency Response Teams — trained in fire suppression, light search and rescue and disaster preparedness — three triage trailers for first aid and seven portable decontamination units.

The county even is able to send a dozen trained people on horseback on search and rescue missions within an hour.

Authorities on the state, county and city levels conduct multiple drills every year to test their responses to disasters involving power plants, dam breaks, terrorist attacks, hazardous materials, tornados, floods and other disasters.

“We plan for the worst possible case scenario because it is easier to downsize than upscale,” Ahlberg said.

For example, in June, officials evacuated 600 people from the U.S. Citizenship and Immigration Services building at Eighth and S streets when a white powder was found in the building.

The powder turned out to be non-hazardous, and some people criticized emergency management for over-reacting, Ahlberg said.

He said the agency’s methodical and thorough reaction ensured no one was in danger — even if the powder had been hazardous.

“What would have happened if it had been anthrax? Nothing,” he said.

Even well-organized systems should be reviewed in light of major U.S. disasters, like Hurricane Katrina, said Al Berndt, assistant director of the Nebraska Emergency Management Agency.

“We’re always looking at what’s around us and for lessons learned,” he said. “We’re already setting priorities for ourselves in looking at evacuations.”

The state’s roles in disaster relief are understanding local emergency management plans, offering assistance — state troopers or the National Guard — and turning to the Federal Emergency Management Agency if additional help is needed.

Berndt said he didn’t know when the state’s internal review of evacuation plans would begin.

Lincoln’s evacuation plan, which probably would be used only in the event of a manmade disaster, works in much the same way as the small-scale evacuation of Salt Creek’s 100-year floodplain. Evacuation routes and shelters in and out of the county have been identified. Those without a car could walk to one of 20 assemblage areas and board StarTran or school buses leaving the city.

“We’re prepared for just about anything,” Ahlberg said.

Berndt said disaster response plans must be fluid and adaptive — and well-understood at the state and local levels.

“It’s up to us to anticipate,” he said. “Then, I’m not sitting here picking my nose without a plan of what to do.”