The US Department of Justice (DOJ) Environment and Natural Resources Division sent a letter to Texas Governor Greg Abbott and Texas Interim Attorney General Angela Colmenero on Thursday over the legality of Texas deploying floating barriers in the Rio Grande. The letter cites several violations of federal law and raises other concerns over the barriers.

The letter states that the barriers “violate federal law, raise humanitarian concerns, present serious risks to public safety and the environment, and may interfere with the federal government’s ability to carry out its official duties.” Specifically, the letter cites 33 U.S.C. § 403, which prohibits any construction on US waters “not affirmatively authorized by Congress.” Additionally, the letter says that Texas does not have an army permit that would allow it to construct the barriers, in violation of 33 C.F.R. §322(a). Lastly, the letter accuses the barriers of violating the Rivers and Harbors Act, which also deals with obtaining army permits to construct in navigable US waters. The DOJ wrote the letter pursuant to Justice Manual 1-10.100, which requires the DOJ to give timely notice to state officials before commencing litigation.

In response to the letter, Abbott stated:

Texas has the sovereign authority to defend our border, under the U.S. Constitution and the Texas Constitution. We have sent the Biden Administration numerous letters detailing our authority, including the one I hand-delivered to President Biden earlier this year. The tragic humanitarian crisis on the border was created because of Biden’s refusal to secure the border. His open border policies encourage migrants to risk their lives crossing illegally through the Rio Grande, instead of safely and legally over a bridge.

The barriers are part of Operation Lone Star. Abbott launched the operation in 2021 to secure the Texas-Mexico border. The effort involves the Texas Department of Public Safety and the Texas National Guard.

This is not the first controversy concerning the barriers. Earlier this month, Mexico’s Ministry of Foreign Relations sent a diplomatic note to the US government expressing its concerns about the deployment of the barriers.