The U.S. Department of Justice (DOJ) filed a lawsuit on Monday (July 24) against Texas and Gov. Greg Abbott for installing a barrier in the Rio Grande. The lawsuit states that Abbott is breaking the Rivers and Harbors Appropriation Act of 1899, which bans the “creation of any obstruction not affirmatively authorized by Congress, to the navigable capacity of any of the waters of the United States.”

Abbott has been criticized for many of the methods his border patrol has used recently against migrants. This includes installing a barrier of large orange buoys in the Rio Grande meant to deter migrants from crossing the river. There are also reports of barrels wrapped in razor wire in the river.

This also comes after a whistleblower from the Texas State Department of Public Safety came forward to make some chilling allegations against Abbott and the Texas Border Patrol. According to the Houston Chronicle, trooper-medic Nicholas Wingate sent an email to his supervisors earlier this month expressing concern about what he describes as “inhumane” treatment of migrants, including children, crossing the U.S.-Mexico border.

In his email, Wingate shared instances where border patrol has withheld water from migrants and pushed them back into the Rio Grande. According to a spokesperson for the Texas Department of Safety, Wingate’s report details an incident where after treating a 4-year-old girl for heat exhaustion, a trooper pushed her and the group she was traveling with back into the river.

“Due to the extreme heat, the order to not give people water needs to be immediately reversed …” Wingate wrote. “I believe we have stepped over a line into the inhumane.” He also addressed the buoy barrier and said, “The wire and barrels in the river need to be taken out as this is nothing but an inhumane trap in high water and low visibility.”

Mexican President Andres Manuel Lopez Obrador has also stepped in, urging Texas voters to reject Gov. Greg Abbott in the next election according to Reuters. And Mexico’s Foreign Minister Alicia Barcena sent a diplomatic letter to the U.S. that states the border buoys are violating a 1944 treaty between Mexico and the U.S.