When I was young, my Dad would take us to a waterfall. I called it Azusa Canyon. Does anyone know where there is a waterfall in this area?

Try Devils Gulch Waterfall in Azusa Canyon

This may be what you're looking for but it's down below. If it's not the right answer disregard. It has a waterfall and is in Azusa, CA. Far as I know the only water we have left up here is the aquaduct. https://www.hikespeak.com/trails/fish-canyon-falls/