Last month, heavy rain closed the massive Sawgrass Mills Mall for three days. Sales for the mall reportedly average $7 million a day. Credit: AL DIAZ adiaz@miamiherald.com

In low-lying areas like South Florida, where rising seas and repeat floods are already driving up insurance costs, the nation’s beleaguered flood program should consider more aggressive efforts to buy out risky property, the Natural Resources Defense Council said Tuesday.

In a study that looked at escalating costs to a program mired in $24 billion in debt, the group found that the National Flood Insurance Program spent $5.5 billion to rebuild 30,000 properties that flooded repeatedly between 1978 and 2015. That’s just a fraction of the 5 million insured. The study also found lower-priced property valued at less than $250,000 typically cost more to rebuild — about 122 percent —than its value.

To end the cycle of “flood, rebuild, repeat,” that often traps lower-income homeowners, the group is pushing for legislation that would make it easier for willing property owners to secure an option […]