While they last, the falls at Malham Cove in the Yorkshire Dales are believed to be the highest in England, thundering off a cliff 260ft (80m high).
Local residents and tourists gathered on Sunday to see the phenomenon, which is believed to be the first time the falls have flowed in hundreds of years.
Stu Gledhill, who filmed the scene, wrote on YouTube: "Talking to two neighbours who are both around 80 and have both lived in Malhamdale all their lives.
"They have never seen this happen before, and some suggestions are that it could be nearly 200 years since it was last recorded."
Malham Cove's amphitheatre-shaped cliff formation was used as a filming location in Harry Potter and the Deathly Hallows and is believed to have been J.R.R. Tolkien's inspiration for the fort of Helm's Deep in The Lord of the Rings.
Don't look down!! Malham Cove with waterfall pic.twitter.com/bapTLPcKa8
— Peter HaII (@jojosh23) December 6, 2015
Melting glaciers caused the original waterfall and a small stream fell over the cliff until centuries ago, when it disappeared underground into the network of caves beneath.
But they could not handle the floodwaters sent thundering through the Dales on Sunday after Storm Desmond brought a month of rainfall in a single day.
Malham Cove in Yorkshire.. With water pouring over for the first time in living memory (apparently!). #StormDesmond pic.twitter.com/d6KBz1FUXD
— Victoria ECY (@EdenCottage) December 6, 2015
The Government declared a major incident as homes were flooded across northern England and Scotland.
Tens of thousands of people remained without power today after an electricity substation in Lancaster was flooded, while the Army was called in to evacuate homes in Cumbria.
A special photo taken by someone out walking in the #Dales around #MalhamCove, water not flowed over since 1700's pic.twitter.com/imfVKpe7yD
— YorkshireTrikeTours (@YorksTrikeTours) December 6, 2015
The Environment Agency still has 46 severe flood warnings in place, warning of a "danger to life", and 80 less serious alerts.
A 90-year-old man died in London on Saturday when he was reportedly blown into the side of a moving bus, while Cumbria Police are searching for an elderly man who fell into a swollen river in Kendal.
Rain and heavy winds have subsided but the Met Office has issued yellow weather warnings for the rest of the week and forecast "persistent rain".
@bbcweather, first waterfall over top of Malham Cove for 400 years, taken this morning. From Stacey McCann, Malham. pic.twitter.com/U7qTWR1XEp
— Stacey McCann (@McCannStacey) December 6, 2015
Comment: One person killed as Storm Desmond causes chaos across UK