Ezra found that Texas' buoys obstructed free navigation in the Rio Grande
Navigable servitude. Article I Section 8 of the Constitution grants the Federal Government ultimate control of navigable waters.
It was one of the arguments in the original filing that I had a suspicion that the courts would favor on enforcing. Part of the Rio Grande that has some the floats isn’t exactly used for boat traffic so it was interesting to see the Court give the entire waterway to the US government.
That all said, with this injunction this quickly for this reason, Texas’ floating barrier is pretty dead, never to return. Even the textualist of the SCOTUS will have a hard time trying to bend backwards on the Constitution explicitly indicating that the various rivers of this country belong to the US government first and foremost.