Catastrophic flooding keeps hitting Hawaii as two back-to-back storms pummeled the islands with rain and damaging winds.

Authorities say it's the worst flooding the state has seen in 20 years, as torrents of water wash out homes, damage roads and threaten to bust through a dam.

The threat of the dam failure in northern Oahu prompted an emergency evacuation of thousands on the morning of March 20. The Hawaii Emergency Management Agency later clarified that the 120-year-old dam had not failed but “is at imminent risk of failure.”

Evacuations were ordered for Haleʻiwa and Waialua, where an alert warned that all roads out are at risk of "imminent failure."

"LEAVE NOW," the alert said.