Community evacuation: Ensuring safe passage
Although they are designed to deliver people safely from danger, emergency evacuations can be just as harrowing as the events that trigger them. “Most of the people killed in disasters are killed during evacuations,” says Lt. Byron Sieber, commander for planning and research for the Grand Forks, N.D., Police Department. “They die in car crashes and flash floods while trying to evacuate. To do it safely, you have to prepare.”
Historically, widespread evacuations have happened infrequently, yet the modern world presents a host of threats — from hazardous materials and hurricanes to fires and bio-terrorism — that prompt the need for well-planned flight patterns. To ensure that evacuations are efficient and safe, local governments are relying on inter-agency agreements, technology and communication with their residents.
A team effort
More than ever, city and county officials are building relationships with state, federal and local partners to create comprehensive emergency response plans. Those partnerships are invaluable in evacuation planning.
“It is important to involve elected officials from state, city and county governments,” Sieber says. “They all have to be on board with a decision to tell thousands of people to leave their homes.”
Grand Forks’ evacuation plan focuses primarily on the threat of flooding. Situated along the Red River, which forms North Dakota’s eastern border, the city has a flat terrain that offers no protection when the river rises; water swelling just one foot above the riverbank will cover a floodplain of one square mile.
Flooding occurs frequently in Grand Forks, and, as a result, the city’s evacuation planners meet regularly with representatives of the Police, Fire, Emergency Medical Services, Public Health, Public Works and Public Relations departments to evaluate existing protocols and consider all contingencies. Communication with local and national weather services is instrumental in giving decision-makers the information they need to call for and manage evacuations. Planners also are in contact with relief organizations — such as the Red Cross, Salvation Army and United Way — that can provide shelter and food for residents who have nowhere to go during an evacuation.
In addition to working with local and private partners, Grand Forks’ planners communicate regularly with state officials. “They provide the authority you need to evacuate,” Sieber explains. “In North Dakota, only the governor can order a forced evacuation. A city ordinance enables our mayor to order an evacuation, but such an order won’t have full authority unless the governor backs it up. This is true in many states.”
It also is true that, for many evacuations, states control major flight routes. That is the case in New Orleans, which is threatened annually by hurricanes and floods.
In preparing for hurricanes Isadore and Lily in 2002, New Orleans officials relied on the Louisiana State Police to clear vehicles and barricades from interstate highway construction sites on routes leading away from the city. Advance planning ensured that police personnel moved quickly, and, while residents ultimately did not have to evacuate, state police personnel were ready to create the contra-flow necessary to lead residents out of New Orleans. (Contra-flow is established by using all highway lanes to move traffic in one direction.)
Terry Tullier, deputy chief of the New Orleans Fire Department and interim director for the city’s Office of Emergency Preparedness, notes that, in addition to public safety and emergency services personnel, New Orleans’ parks personnel are on call during natural disasters. “Winds from a hurricane will knock down trees, and our Parks Department and local utility company must be prepared to clear them out of the way,” he explains.
Some disasters come with notice, while others hit without warning. As a result, planners have to factor in lead times for communicating and implementing evacuations.
For some planners, time is on their side. For example, in Grand Forks, emergency managers monitored the development of a major spring flood in 1997 by tracking winter snowfall and melting rates. “We geared up slowly and reported regularly to the public through the media,” Sieber says. “The long lead time enabled us to plan a two-stage evacuation. The first stage was voluntary; second came an ordered evacuation.”
In New Orleans, managers have days rather than months to prepare for evacuation during a hurricane. “Our experts say that it will take about 72 hours to evacuate New Orleans and the surrounding parishes,” Tullier says. “Preparations must consider the low-lying parishes at the mouth of the Mississippi River and to the east of the city. People there will have to come through New Orleans if there is an evacuation. This means that they have to go very early.”
However, at 72 hours out, a hurricane can do anything; it might grow or shrink, hit land or fizzle out. The weather services can make predictions, but they cannot issue guarantees, making it more difficult to manage the 72-hour window. Additionally, Louisiana highways are shut down when wind speeds reach 40 miles per hour, further limiting the time available for a major evacuation.
To prepare the public for a possible evacuation, New Orleans officials begin communicating with residents as much as seven days before a hurricane is predicted to hit. “This year, the weather service estimated that Isadore would affect us on a Wednesday, so we advised the public on Thursday, a week before, to use the coming weekend to prepare to leave,” Tullier says. “This way on Monday and Tuesday, if things got nasty, people could lock their doors, get in the car and go on a moment’s notice.”
The silent partner
A moment’s notice would be a luxury in Denver, where, as a transportation hub, the city and county emphasize hazardous material in evacuation planning. “We don’t know where or when an event will occur, so we have to do most of our planning on the fly when something does happen,” says David Sullivan, acting director for Denver’s Office of Emergency Management. “We have to identify the affected area, decide whether to shelter in place or to evacuate, set routes and communicate with the public very quickly.”
To enhance planners’ foresight, Denver is expanding its GIS to show the locations of HAZMAT storage facilities and transportation routes. “We’ve requested that the city add mapping levels that we can use for evacuation planning,” Sullivan says. “With this system, we [will be able to] map areas surrounding possible spills and figure out how many people must move and what routes they should take. We can also plan the numbers of shelters people will need.”
Like Denver, other cities are employing technology as a silent, yet indispensable partner in expanding planning, tracking and communication capabilities. For example, in Grand Forks, planners use GIS to map electrical power lines, fire hydrants, sluice gates and other infrastructure that must be shut down as floodwaters rise and the potential for evacuation increases. Additionally, Grand Forks and New Orleans are applying satellite global positioning technology to their planning. “Satellites can provide information about where and how fast water levels are rising,” Tullier says.
While GIS can assist with internal decision-making, more traditional media, such as television and radio, are the primary tools for communicating evacuation plans to the public. In Grand Forks, a cable interrupt system allows the city to communicate with residents directly via television. “The system is activated by picking up a phone in our dispatch center, and we can deliver a message to everyone watching cable television,” Sieber says.
Denver is similarly connected to area media. The Office of Emergency Management uses the Emergency Alert System (EAS), which replaced the conventional Emergency Broadcast System. Using digital technology, the EAS can transmit live or recorded messages to broadcast media and to specially equipped consumer televisions, radios, pagers and other digital devices. The EAS also allows unattended media to receive and transmit emergency messages automatically.
Both Denver and New Orleans have Reverse 9-1-1 capabilities, allowing them to call thousands of residents at once with recorded messages. However, Tullier notes that Reverse 9-1-1 does have drawbacks; its success depends on the availability of phone lines and the residents’ willingness to answer their phones.
He and other planners have similar concerns about Web-based communication. For example, Denver, Grand Forks and New Orleans all place emergency advisories on their Web sites, but they do not rely heavily on online transmissions, reasoning that many people do not own computers.
Of course, television and radio have their shortcomings as well, making it necessary for emergency departments to retain their oldest technology — the bullhorn. Tullier notes that street-by-street canvassing is part of any evacuation and is especially important in communities with non-English-speaking residents.
Minds of their own
While cities and counties have multiple tools to communicate with residents, getting the residents to listen is another matter. In any disaster, there are die-hards who refuse to leave their homes, and, as a result, cities and counties have to be ready to enforce their evacuation plans.
That was the case during the 1997 flood in Grand Forks, where some residents stayed put, even when evacuation was ordered. “In some cases, we had to take people out of their homes physically,” Sieber says, noting that some residents were unable to move themselves while others were simply stubborn and did not want to leave their homes.
Ultimately, approximately 50,000 people from Grand Forks and surrounding communities fled the flood. “Not a single person was lost,” Sieber says.
Despite their success in that event, Grand Forks’ emergency planners are re-formulating their evacuation plans to manage return as well as departure from the city. Sieber notes that, in 1997, flooding was extensive, and residents grew impatient while waiting for the water to recede. In the two weeks following the flood, only a few thousand people were able to return to their homes; others had to wait up to a month. As a result, Sieber believes the next evacuation will prove more difficult to manage.
“We’re worried about the next time,” he says. “We think that a lot of people might refuse to leave or try to come back early. We’re making new plans with that in mind.”
Tullier calls the decision to evacuate “gut wrenching,” and it is little wonder. To predict the path of a disaster and manage the behavior of residents in that path, evacuation planners must be skilled at gathering and sorting information, communicating and establishing order. By coordinating local departments, establishing cooperative agreements and employing technological resources, they are improving their odds for safe flight.
Michael Fickes is a Baltimore-based freelance writer.