Due to all the rain California has been receiving, people are once again talking about the threat of an ARkStorm and the storm of 1861-1862. Research out last year found that climate change is dramatically increasing the risk of such an event, which threatens the whole Western United States and could cause economic damage similar to a San Andreas or Cascadia earthquake.
“By the end of the 21st century, we find a 300 – 400+ % increase in the relative risk of such an event across the entire state. One specific statistic that my colleagues and I found particularly eyebrow-raising: on our current emissions trajectory, at least one occurrence of an 1862-level precipitation event is more likely than not over the next 40 years (between 2018 and 2060), with multiple occurrences plausible between now and the end of the century. In practical terms, this means that what is today considered to be the “200-year flood”—an event that would overwhelm the vast majority of California’s flood defenses and water infrastructure—will become the “40-50 year flood” in the coming decades.”
Climate change and ARkStorm Research study: https://weatherwest.com/archives/6252
News article: https://www.latimes.com/local/california/la-me-ln-mega-storm-dam-failure-20190218-story.html
USGS ARkStorm Report (2011): https://pubs.usgs.gov/of/2010/1312/