So parallels can be made to other places to show the danger. It's a slot canyon; only one that's generally constantly full versus empty most the year until the

So parallels can be made to other places to show the danger. It's a slot canyon; only one that's generally constantly full versus empty most the year until the monsoon hits like those here in the US where I am. But the danger remains the same, the sandstone geology allows for it to create very deep and fast flowing situation due to Bernoulli's principle. Even more so for constrictions in the rock which form natural venturi. <s>I looked but was not able to find CFM/CMM for the input and output</s>; but that would give a reasonable idea of what the volume of the canyon must be because what goes in must come out. So the volume of the flow at the outlet and inlet gives a very good idea of just how crazy it can be. Edit: Input flows: https://nrfa.ceh.ac.uk/data/station/meanflow/27096 https://nrfa.ceh.ac.uk/data/station/meanflow/27096 Output flows: https://nrfa.ceh.ac.uk/data/station/meanflow/27043 https://nrfa.ceh.ac.uk/data/station/meanflow/27043 https://en.wikipedia.org/wiki/Slot_canyon https://en.wikipedia.org/wiki/Slot_canyon https://en.wikipedia.org/wiki/Bernoulli%27s_principle https://en.wikipedia.org/wiki/Bernoulli%27s_principle