Not a big river by any means but it is constantly flowing. In the canyon area’s it narrows but gets pretty fast. Class 5 and 6 rapids in the canyon when the water is up. The river is a whole different story when it comes to a fence. Since the border is the middle of the river you’ll never see a fence on the Texas southern border.
That’s the entire length of Texas. Cattle water, boating, fishing, etc. How do you block it eith a fence that makes sense?