How do rescue teams search a flooded city?

Hurricanes can have deadly consequences, and so can tornadoes and lightning. But floods, particularly inland floods like the kind that overtake city streets and buildings, are the leading cause of weather-related death in the U.S.

Floodwater causes nearly as many fatalities each year as hurricanes, tornadoes and lightning combined, a stark reality that makes flood response all the more critical [source: Office of Insurance and Safety Fire Commissioner].

Some floodwater rescue teams comprise local and regional responders. These responders may be members of a community's fire, police or ambulance departments who have been cross-trained in basic water rescue techniques. Or they may be volunteers who have received similar training.

In addition, elite teams of specially trained flood rescuers may be mobilized as part of a regional or national response. In the U.S., the National Fire Protection Association (NFPA) outlines the training standards for these teams in its detailed Technical Rescuer Professional Qualifications manual, which is used a benchmark for rescue training [source: Turnbull].

Rope skills, such as knot tying and rope systems, are a crucial element of a well-versed water rescue team. In addition, teams must know how to deploy a rescue stretcher, also known as a "litter," and safely return it to the watercraft with a passenger aboard. They'll also have standard rescue equipment on hand, such as whistles, megaphones to communicate, extra life jackets, rain gear, lanterns and flares [source: North Carolina Department of Public SafetyIRIN News].

Teams must learn to navigate rescue boats through city streets and contend with buildings, vehicles, hidden snags and dangerous debris. Floodwaters may be contaminated with raw sewage and chemicals. What's more, the water often flows swiftly, rises quickly and forms strange currents because of the many obstacles it encounters [sources: Environmental Protection Agency, IRIN News].

Before a flood rescue team can spring into action, however, it needs to know where to go. Rescuers use maps to figure out which areas are likely to be flooded; they also learn how to locate survivors in the absence of landmarks. Without landmarks, those seeking rescue can become confused when relaying their locations.

In some situations, teams are dispatched by local emergency services operators receiving distress calls via cell phones. They may rely on information from on-site volunteers who can identify people trapped by floodwaters. In addition, teams may receive communication from air support, such as helicopters flying over rain-soaked areas to find people stranded by rising waters. It's a far cry from simply driving around a flooded city in a boat, looking for survivors.

A flood survivor has taken refuge in the second story of an office building that's now a makeshift swimming pool. Or a stranded homeowner has crawled onto the roof to find safety from floodwater atop the shingles.

Rescuing floodwater victims is not as simple as sidling a boat up to a building. Rushing water makes it nearly impossible to safely transfer a person from a stationary object onto an undulating boat, so rescuers must learn hydrology, which is the study of water and, in part, its behavior under specific circumstances [source: United States Geological Survey].

Understanding how water acts when it is moving quickly through a confined channel helps rescuers act more effectively. For example, they learn how to angle a boat so it is not fighting a fast-moving current, and learn to "read" the water's surface to discern hidden obstacles such as submerged posts or vehicles.

In addition, floodwater rescue teams often send a member upstream (or up the street, as the case may be) to let them know large debris is headed their way. Other crew members are stationed downstream with ropes in hand so they can save anyone who may fall in the water before boarding the rescue boat.

Flood rescue teams are trained to put precise techniques into action, such as sending a second boat upstream to create an eddy -- a circular current that runs opposite of the rushing floodwater -- that will hold another boat steady against the side of a building so rescuers can help survivors aboard.

This rescue will happen again and again, until everyone stranded has been transported to safety. Rescue boats can only fit three or four passengers in addition to the crew, so teams will first take the young, old and injured to safety — sometimes performing first aid in the process. If someone does fall into the water while waiting to be rescued, a spotter on the boat will try to keep them in sight until they can be pulled out.

Once the rescue team's passengers reach land, they will be transferred to relief agencies that will offer food, shelter and other assistance in the wake of a natural disaster [source: IRIN News].