https://www.independent.org/news/article.asp?id=10524

> “The potential losses generated by NFIP have created substantial financial exposure for the federal government and U.S. taxpayers,” the U.S. Government Accountability Office concluded in a February 2013 report to Congress. “While Congress and FEMA intended that NFIP be funded with premiums collected from policyholders and not with tax dollars, the program was, by design, not actuarially sound.”

> In 2012, in an attempt to provide some financial stability to the ailing NFIP, which was $20 billion in debt at the time, Congress required FEMA to phase out many of the subsidized policies in order to more accurately reflect cost and risk. Existing policyholders naturally balked at paying the higher premiums, however, and the backlash was strong enough that politicians quickly caved and rescinded the requirements, restoring the grandfathering of subsidized policies and capping premium increases.

tl;dr: Beachfront property owners don't want to pay for their own flood insurance, so you get to pay for it instead. In October 2017 the government wrote off $16 billion of that debt, and as of February 2018 it was still in debt to the tune of $20.5 billion.

Thanks to these subsidies, people will keep rebuilding in the same idiotic places knowing that it will flood again, which is fine because you're paying for the bulk of their insurance.