NEW ORLEANS (AP) — Increases in federal flood insurance premiums that are projected to surpass 700% over the coming years are already leading people to back out of home purchases and will likely lead to an exodus of residents and businesses from southern Louisiana, officials told a federal judge Thursday in New Orleans.

The testimony came in a hearing in a lawsuit Louisiana and nine other states filed against the federal government to block sharp increases in national flood insurance rates. A phase-in of the new rates began in 2021. Annual increases are limited to 18%. The Federal Emergen...