Concrete/Hillside Waterslides in Texas?

I have always loved the old school hillside water slides that were made out of concrete but there so hard to find. The only hillside slide I'm aware of is The Fun Spot Water Slide outside of Galveston, TX. I live in Austin and that's a good 3 hour drive. So, I was wondering if y'all are aware of of concrete/hillside water slides in central Texas?

There's a concrete tube chute in a public park in New Braunfels. I've only ever seen it on my way to Schlitterbahn, though, never actually rode it.