This story was originally published Dec. 15, 2012:

People rebuilding homes in New Jersey damaged by Sandy should raise them higher, the Federal Emergency Management Agency said Friday.

FEMA gave details on an advisory flood map for 10 counties that shows the risk of flooding is worse than was believed when flood-zone maps were adopted nearly 30 years ago. The water levels in floods could be one to five feet higher in most coastal flood zones, the agency said.

The map is to be released Saturday to guide property owners and communities as they decide how to rebuild.

"It's important as we move forward that people know their risk," said Ryan Pietrimeli, the FEMA risk analysis branch chief.

The maps being made public are based on data gathered as the agency sought to update maps it uses to determine premiums in the federal flood insurance program.

The information predates when Sandy crashed into New Jersey's shore in October, devastating many coastal areas. The maps do not incorporate projections that the sea level will rise at an accelerating rate.

The official flood insurance map is due to be unveiled next year and adopted in 2014.

Pietrimeli said communities should adopt the map to be made public Saturday into building codes. In some places, it will mean structures should be built on pilings or piers. He also said there could be tougher codes in areas where waves could crash into buildings.

Pietrimeli said one incentive for homeowners to follow the new map is that they can receive discounts on flood insurance if they elevate their homes above levels currently required.

The map covers 194 municipalities in Atlantic, Bergen, Burlington, Cape May, Essex, Hudson, Middlesex, Monmouth, Ocean and Union Counties.

The maps are to be posted at http://www.region2coastal.com .