The county board unanimously approved a new floodplain ordinance during its Tuesday meeting that will require more property owners to get zoning permits before building decks and other structures on their land.

The county board adopted the ordinance ahead of the Federal Emergency Management Agency’s new floodplain maps taking effect next month. The City Council approved a similar ordinance for Austin on Aug. 19. The changes come as part of electronic elevation mapping by FEMA after the 2007 floods in southeast Minnesota. State legislators funded the study in order to update Minnesota’s land and flood elevations.

According to Environmental Services Director Angie Knish, property owners in the floodplains will be required to secure a $30 zoning permit before building a deck, porch or new structure on their property. Permits will not be required for repairs, siding or interior work.

Property owners will be prohibited from storing sand, gravel, machinery or equipment in floodways, since currents could be a risk. The new ordinance also prohibits recreational facilities and storage of recreational vehicles in the floodway.

The ordinance also states that if a structure sustains two floods in 10 years that damage 25 percent of the property value or more, the property owners must flood proof or evaluate the structure to remain in its current location. The old rate required action if it damaged a structure’s value by 50 percent.

The flood plain is the entire area along a stream or river up to that experiences flooding during a big water event. The flood plain encompasses the floodway — areas near the stream that carry flood flows downstream — and the flood fringe — areas inundated by flood waters that don’t experience strong currents.

The new FEMA maps take effect Sept. 4 whether the county board passed the ordinance or not, according to Knish.

“The maps are truly a done deal,” Knish told the board Tuesday.

While multiple residents voiced concerns over the changes to the Council, no one attended Tuesday’s public hearing for the changes in the county.

—Trey Mewes contributed to this report.