A bridge over the river (just North of the Barrier Gates) will provide Border Patrol (and first responders) rapid access, even during floods, as well as mounting cameras and sensors to monitor the river.
New designs are now being employed across rivers that cross the US/Mexican Border, Like the Tijuana River in San Diego, and the San Pedro River in Arizona.
Bollards with flood gates block the riverbeds, overwatched by a separate nearby bridge, providing high speed access to Border Patrol and Emergency Services, and a mounting platform for technology to monitor straight up and down the river.