Waffle House serves hungry customers bacon, eggs and hash browns, but when disaster strikes, the iconic chain serves up valuable intel to the government.

The Federal Emergency Management Agency has developed an unofficial, color-coded "Waffle House Index" to help make assessments before sending response teams to areas hit by such natural disasters as tornadoes, floods or hurricanes.

“When business like that are closed, that’s a good indication that resources are probably going to be needed for the survivors there in that area,” explained Will Booher of Florida’s Division of Emergency Management.

After a disaster, officials call a restaurant in the affected area, and ask what's on the menu. If the restaurant is serving everything, it means there is water and electricity and that the index is green. If the menu has been scaled back, the index is yellow, which means there's water but no power.

In the rare event a Waffle House is completely shut down, the index is red and that usually means there's big trouble.

“I guess our reputation has been that if we’re able to get back open, things might be bad, but they’re not horrible," said Walt Ehmer, chief operating officer of the 1,600-store chain. "But, if we don’t happen to be able to be doing business, then that must be a sign that the community is in really bad shape.”

Current FEMA Director Craig Fugate came up with the Waffle House Index during his eight years responding to hurricanes as the head of Florida’s Division of Emergency Management. In 2009, Fugate told an audience at the inaugural Random Hacks of Kindness, Disaster Relief Codejam event in Washington that practical indicators are much more informative than checking with a host of local utilities and law enforcement agencies when initially trying to assess a stricken area. And Waffle House is as reliable a practical indicator as there is, he said.

"If you get there and the Waffle House is closed, or in the case of Mississippi on the coast, it's a slab, that's red," Fugate said.

It's no accident that Waffle House is so valued in disaster assessment. After Hurricane Katrina destroyed seven of its restaurants and forced 100 more to close in 2005, the chain revamped its disaster preparedness, according to The Wall Street Journal. Much of the effort went into creating a limited menu based on diminished capabilities and keeping supplies near storm-riddled areas.

Ehmer is glad his company can help the feds race to the aid of disaster-stricken communities buffeted by disasters. But he is even more proud of the direct role Waffle House plays in the wake of disasters.

"It's the one thing we know we can do," he said. "We can be there and serve food for people and, after many of the storms…it's very often that we'll hear from folks, 'This is the first hot meal I've had in a week.”