The proposal to raise Mandeville’s seawall by 1 foot brought skepticism from a standing-room-only crowd at a public meeting this week. Speakers questioned the cost of the plan, its benefits and the look it would have on the city’s lakefront. Mayor Donald Villere told the audience the $2 million project could result in FEMA changing its flood risk maps to move the area out of the V zone, the most hazardous category, which has high insurance premiums. Some of those in attendance wanted to know how many people would benefit from the better insurance rates and wanted the administration to do a cost/benefit analysis. The proposal to raise the 5½-foot seawall along a stretch of Lake Pontchartrain by a foot wouldn’t have much effect on the flooding that periodically covers Lakeshore Drive. Villere said that to reduce most of flooding they would need to raise the wall 2 feet, building pump stations and installing gates at the mouths of bayous. The estimated cost for such a project could be as high as $20 million.