A U.S. federal judge has ordered Texas to remove a section of concrete barrier lining the banks of the Rio Grande River that was intended to deter migrants from crossing into the U.S. from Mexico. The judge ruled the barrier violates a treaty between the U.S. and Mexico that outlines how the countries are supposed to manage the river boundary. In his order, the judge said the barrier creates an obstacle along the normal flow of the river and called for its immediate removal. The state of Texas argued the barrier was needed for border security reasons, but the court sided with the environmental arguments.