Get a copy of What If? 2 and Randall’s other books at: https://xkcd.com/booksMore serious answers to absurd questions at: https://what-if.xkcd.com/This quest...
Also that only 1/3 of the water flows over the falls. The rest is diverted off to make electricity.
And if we have found a way to reinforce a straw, then we will have found a way to reinforce the planet as well. Danger averted.