The U.S. government has the National Flood Insurance Program (www.floodsmart.gov). There's not much of an excuse to not get it, much like renter's insurance.
It's more expensive but that's because there is more risk and everything is based on risk. You can get just about any type of insurance through an Excess & Surplus carrier that will sell it to your All-State's and State Farm's.
Oh and the US Flood Insurance Program only protects up to $250k per home/condo, and a bit more for businesses. Umbrella coverage, or excess flood coverage can cover the rest... and generally speaking its cheap.
Oh and btw, windstorm and hail coverage is expensive as hell because of the high risk involved. Don't want to pay it? Don't live on a coastline.