The record-breaking rainfall and subsequent flooding Monday around Oklahoma City caused millions of dollars in damage to homes and cars.

As many Oklahomans pick up the pieces, knowing how to be flood-protected has never proved more important, said Gary Knight, owner of Knights Insurance in Norman.

But for many financially burdened Oklahomans, purchasing flood insurance and knowing where the risk areas are located is not high on the priority list, Knight said.

“A lot of people always try to beat it,” he said. “They don’t want to carry the flood insurance because they’re carrying regular insurance and can’t afford it.”

Flood damage is not covered by homeowners or renters’ insurance and must be purchased for an additional premium, with rates depending on the particular flood plain, Knight said.

The flooding on Monday was a 1-in-500 weather event, with the Oklahoma Mesonet northern Oklahoma City station measuring greater than 9.6 inches of rain in a 12-hour period, according to the Oklahoma Mesonet site.

“The expectation over a 12-hour period of time in Oklahoma County would be that you would see a rainfall of 9.6 inches only once every 500 years,” said Renee McPherson, meteorology professor and associate director of the Oklahoma Climatological Survey. “That’s a statistical-based estimate using the data that we have.”

The type of storm that affected the Oklahoma City area on Monday is known in radar terminology as training echoes, elements that combine in a certain area allowing multiple storms to form one after another, McPherson said.

“The thunderstorms follow each other in a train so you get a series of thunderstorms in the same area,” she said. “If they have heavy precipitation like they did on Monday and they start redeveloping behind each other, that’s where we get substantial localized rainfall.”

Despite the damage done Monday, Oklahomans can be grateful the heaviest rainfall occurred during the day. Night-time flooding in Arkansas this past week caused the death of at least 18 people, with three still missing, according to an AP report.

“The difference we had in Oklahoma is that the flooding happened during the day, people were aware it was occurring” McPherson said. “In Arkansas, people were asleep. We were very fortunate in Oklahoma City and Edmond.”

There are many factors that contribute to flash flooding, but the City of Norman has improved its situation in recent years by upgrading the storm water system. The utilities division has undergone significant structural upgrades to reduce the amount of localized flooding, McPherson said.

Shawn O’Leary, public works director for Norman, said the city is one of the more regulatory cities in Oklahoma when it comes to flood management.

Norman is proactive in discouraging further development and heavily regulates improvements on structures in flood plains, he said.

“Nearly 90 percent of people in this country located in flood plains are without flood insurance and are really vulnerable,” O’Leary said. “It’s a real point of frustration for those of us that manage flood plains.”

O’Leary said the city sends letters to all homes in flood-plain districts. He thinks it is very important for residents of Norman to get in touch with the status of their property and learn how to be safe in the event of a flood.

“In August 2007, we had about 7 inches of rain in a span of about three to four hours,” O’Leary said. “Not as much as they got in Oklahoma City, but that number begins to create lots of problems.”

For more information on the hazards of flooding in the Norman area and how to get better protected, visit www.ci.norman.ok.us/content/flood-hazard-protection.