The phrase "historic flooding" means that there is a very large and significant amount of water covering an area, and it is considered to be an extremely rare or unprecedented event in that specific place. Full definition
«I spoke with individuals and businesses affected by historic flooding,» he recalled. (auburnpub.com)
There's no denying, these recent historic floods we've been having in the past couple of years have only shown how our aging infrastructure needs to be fixed. (politics.stackexchange.com)
We also provided funds to Texas organization Wharton County Stray Pet Outreach Team (SPOT), which rescued and provided medical care for cats after historic flooding in the county. (alleycat.org)