About 3,500 Plano property owners can expect a notice in the mail about a new federal flood plain map involving their homes or land.
The Federal Emergency Management Agency has proposed changes to the 100-year flood plain.
About 340 additional homeowners will now have property designated in the flood plain, said Jerry Cosgrove, Plano Public Works director. However, others may no longer be at risk.
"This is one of the areas that has changed dramatically," Cosgrove said, describing how development and construction can change the direction in which water flows and runs off. "Even if you're not in the 100-year flood plain, it doesn't mean there isn't any risk."
The proposal could have expensive consequences for homeowners such as Kathy Shelton, who has lived in her home about four blocks from Prairie Creek for about three decades.
"It hasn't flooded since I've been here," she said. "If it's going to be forced on us and we have to pay insurance, I don't think I'm going to be very happy about that."
Cosgrove said mortgage companies may require the owners of homes designated in the flood plain to obtain insurance.
"Your mortgage company most likely will say, if you're in the 100-year flood plain, we want you to have insurance," he said.
Homeowners may appeal the FEMA map from now until December.