(AP) — The Army Corps of Engineers has awarded contracts totaling nearly $1 billion to replace short barriers with tall fences along two sections of the U.S.-Mexico border.

The Corps of Engineers said in a statement Wednesday that 46 miles (74 kilometers) of fencing will be installed near Columbus, New Mexico, and 11 miles (18 kilometers) will be installed near Yuma, Arizona.

The fencing in New Mexico will be installed by SLSCo. of Galveston, Texas, which got a $789 million contract. Barnard Construction Co. Inc., of Bozeman, Montana, was awarded a $187 million contract for the other work.

The contractors will remove waist-length fencing, known as vehicle barriers, and replace it with tall fencing that will go up to 30-feet high in New Mexico. The new fencing is similar to what’s already in place in large parts of the border.

The Corps said the fencing will help “impede and deny illegal border crossings and smuggling of drugs and humans.”

The Department of Homeland Security has not responded to an inquiry for comment.

Laiken Jordahl, borderlands campaigner for the Center for Biological Diversity, said the additional fencing will sever a known corridor for a wide range of species. “It’s hard to explain just how much the wall impacts the entire ecosystem,” Jordahl said.