AUSTIN, Texas – The most common, and most expensive, natural disaster facing Americans is flooding. In the devastating hurricanes that have recently hit the nation, like Sandy and Harvey, it was water, not wind that caused the gravest havoc and loss of life. Flooding is by no means limited to floodplains. Twenty-five to 30 percent of flood claims paid are for properties outside high-risk flood areas, or Special Flood Hazard Areas (SFHAs). And as recently reported after the severe flooding in Houston after Hurricane Harvey struck, just 15 percent of the 1.6 million...