New Orleans City Hall has joined residents of Algiers Point in appealing new FEMA flood maps that the residents say incorrectly show their properties as being at risk of flooding during rainstorms, a designation that would carry with it significantly higher insurance premiums.

At least 80 West Bank residents have filed appeals challenging the maps.

They paid for surveys themselves to show their properties are at a high enough elevation to avoid the risk of flooding, said Vlad Ghelase, an Algiers Point resident who has been organizing the opposition to the new maps.

“It’s absurd to have a flood zone shown in Algiers Point when Broadmoor or Lakeview, which were underwater (after Hurricane Katrina), don’t,” he said.

Ghelase and other residents have been organizing an appeal in recent months after learning that most of Algiers Point was reclassified from FEMA’s Flood Zone X — which means properties will not flood even during a rainstorm with a 1 percent chance of occurring in a given year — to Flood Zone A, which means there is a risk of flooding under those conditions. Those residents had been pushing the city to get involved in their appeal.

That assistance came after residents pushed for the city’s help during one of Mayor Mitch Landrieu’s community budget meetings, and a second meeting was called just to discuss the new maps. Residents, city officials and FEMA representatives all attended that session.

In a news release sent out Friday, the city said it has filed its own appeal, citing problems with the way FEMA had “modeled” the area.

“I have asked FEMA to review these issues to ensure the accuracy of the flood maps for the residents of New Orleans,” Landrieu said in the release. “It is imperative that the best possible science is used and that the maps show the actual risk. I have asked FEMA to review the appeal and to make the necessary adjustments to the maps where appropriate.”

According to the city, a key problem with the maps is that they incorrectly show Opelousas Avenue as a ridge. That means FEMA’s modeling assumed the street would act like a levee, preventing water from receding from the area and increasing the flood risk.

Those elevations were calculated using scans taken from the air, and Ghelase said he suspects the oak trees that line Opelousas may have created interference that led to the incorrect idea that the street is elevated.

FEMA’s models also do not take into account work the Sewerage & Water Board has done to improve drainage in the area, according to the city.

Residents have spent more than $14,000 getting elevation certificates to prove their properties are actually above flood level and have submitted letters outlining the problems they see with the maps, Ghelase said.

Thursday was the last day to file appeals with FEMA, though the city and residents will have another month to provide supporting documentation as they try to prove their case.

Follow Jeff Adelson on Twitter, @jadelson.