More than 1,200 Suffolk property owners will be affected by upcoming floodplain map changes, city leaders announced Wednesday.

The Federal Emergency Management Agency is in the process of updating the nation’s floodplain maps, including those for Suffolk. Flood risk can change over time because of such factors as dams, surface erosion, development and more.

In the updated maps, the flood zone now covers 554 parcels it did not cover before, and leaves out 716 parcels that were included before. Homeowners who are now in high-risk areas and have federally backed mortgages are required to purchase flood insurance.

The changes are projected to take effect on Nov. 16. A public information meeting is scheduled for 6:30 p.m. July 21 at King’s Fork High School. Affected property owners will be receiving letters.

Nick Morici of FEMA Region III, which includes Virginia, encouraged property owners to attend the meeting and communicate with local government resources to get more information on their flood risk status.

“Just because it hasn’t happened to you doesn’t mean it cannot happen,” Morici said. “Make sure you are planning.”

Those in high-risk areas need flood insurance because general homeowners’ policies do not cover floods. Flood insurance can be costly, but newly affected property owners can lock in a lower rate if they purchase flood insurance now, before the changes take effect.

High-risk areas have at least a 1-percent annual chance of flooding, which equates to about a 26-percent chance of flooding over the life of a 30-year mortgage, according to FloodSmart.gov.

FEMA was ordered by Congress in 2003 to develop the new flood maps. Morici estimated that earlier flood maps for Suffolk could date back as much as 20 years.

Even people who are not in high-risk areas still are at risk, he said. Everyone lives in a flood zone, though the level of risk varies.

“Keeping their eye on how the flood maps change is very important,” Morici said. The new information is useful at all levels, from the federal government down to each individual family’s emergency plan. “Protecting your family and your property should be a critical part of every emergency management plan.”

Changes to the city’s floodplain ordinance will be considered by the Planning Commission in August and by City Council in September.

To see the outdated flood map for your area, click here. The new flood maps are not yet available online.