They don’t say “Gwa-deh-loo-pay” where I’m from.
They say “Gwa-deh-loop”, I can’t tell you why they actually lost a syllable on that word. Texans are notorious for adding syllables to words with their drawls.
However you say it, it’s a beautiful little river in S. Texas.
But such a beautiful day to be out, and enjoying the peaceful water.