I'm sure there are many other towns (and maybe counties and maybe states) that have fought and been at least somewhat successful.
I don't know of any actual suits as in 'we have standing' -> in our town's case, we got the new rates suspended until REAL engineers could do the surveys.
This is an issue that has affected millions of people; I wish someone would simply call the tune and do a class action— actually I wish they would hang the bastards, but that will never happen. My house is so obviously NOT in a flood zone, it is outrageous, and many others in the area. Most are too poor to pay the surveying fees, or the insurance, so some were forced to sell, some borrowed to pay off their mortgage, but now they can’t sell the property. Obviously they know this.
The engineers need to do a hydrologic study.