GRESHAM, Ore. (KOIN) — FEMA is updating its Flood Insurance Rate Maps (FIRMs) for Multnomah County, which could result in higher insurance rates for residents.

City and county officials say they don’t expect sweeping changes.

But properties that currently fall into a “higher risk zone”, when they previously didn’t, could see hikes in insurance rates.

Gresham’s Natural Resources Planner Tina Osterink says the biggest question asked at a FEMA open house was: “Why am I in the floodplain? Because I wasn’t in the past.”

Part of the reason FIRMs are changing is because of the Sandy River.

“For the most part, the Sandy River is one of the rivers in the area that migrates,” Multnomah County Planning Director Mike Cerbone explained.

That means, from year-to-year, it can change its location.

The changing landscape of the river leaves some homes and businesses more vulnerable to flooding. The FEMA FIRMs for Multnomah County forecast risk zones for the next 100 years.

FEMA plans to update FIRMs for other nearby areas in the next few months.