More than 1,600 Houston residents whose properties flooded during and after Hurricane Harvey may need to elevate their homes if they want to continue living there.

The city’s Public Works Department is getting ready to notify property owners in floodplains that their structures have been declared “substantially damaged.” The department said more than 30,500 structures sitting within the city’s floodplains took on some flooding from the hurricane and the heavy rains that followed, the Houston Chronicle reported.

Those homes will need additional, expensive repairs to meet current building codes. Such repairs could mean physically raising homes, an upgrade officials said could cost more than $150,000.

Public Works officials said more than 1,600 letters are going out this month to the first set of properties identified as so severely damaged that repairs would cost more than 50 percent of the structure’s market value.

“The letter of substantial damage is a tool for the city of Houston to ensure people are not repairing houses that really shouldn’t be repaired,” said Ed Wolff, a resident who received his letter Tuesday.

Wolff said his home needs the designation so he can be eligible for a mitigation loan to elevate his house, which flooded for the third time in three years. Wolff said he plans to elevate his house 6 feet (1.8 meters), which is 3 feet (1 meter) above the water line from Harvey. He said the elevation will cost more than $270,000.

“The expense is tremendous,” said Houston Mayor Pro Tem Ellen Cohen. “It’s difficult, but there are going to be decisions that have to be made.”

The Public Works Department is still working with the Federal Emergency Management Agency to get a final count of properties that will be identified.

(AP)