Under new maps, a thousand more Nashville homes are officially in the flood plain

A thousand homeowners in Davidson County will receive a letter this week informing them of unwelcome — but not unexpected — news: Your house is in the 100-year flood plain.

Updated maps from FEMA, the Army Corps of Engineers and Metro Water Services show new areas within the flood plain that were previously unmapped. The agencies are taking a closer look at tributary creeks rather than just main waterways and using more sophisticated mapping equipment.

But Sonia Allman of Metro Water says the flood plain isn’t expanding. It’s just being mapped more precisely.

“The risk is the same as it always was,” she says. “What has changed is we are better aware of that risk and can make proper decisions.”

Allman contends the changes have little to do with runoff from new developments or risks associated with climate change. The biggest changes, as seen on the published maps, are around Richland Creek and neighborhoods surrounding Percy Priest Lake.

Still, having a home or business in a flood plain has financial implications, including potentially lowering its market value. For most of these property owners, flood insurance becomes a requirement.

The new maps officially take effect February 25. But homeowners receiving letters this week are advised to obtain flood insurance before the maps become official. That should lock in a lower starting rate, and FEMA caps annual increases to 18%.