A diagram of the flood areas of the December 1861-January 1862 California Megastorm. The same areas are expected to be flooded again if another ARkStorm was to impact California, which is predicted to cause over $750 billion (2011 USD), making it more disastrous than California's long-overdue major earthquake. California is currently overdue for a Megastorm, and such an event would have severe impacts on the entire U.S. economy.