The National Guard has already built nine miles of the multi-layered barrier, which includes access roads, lighting, and surveillance cameras. Three and one-half of the final miles will be in a corridor up to 700 feet wide, and plans call for filling in a canyon and wetlands so that Border Patrol agents can patrol more efficiently. "The terrain favors smugglers," says Michael Hance, field operation supervisor with the Border Patrol’s San Diego sector. "We want to reverse that trend so that the terrain favors the Border Patrol."
The California Coastal Commission, a state agency, has opposed the federal government’s plan because of its environmental impacts. Dirt fill for the project will likely wash downstream, choking the Tijuana Estuary, and construction work could harm imperiled species, such as the southwestern willow flycatcher. But Peter Douglas, the commission’s executive director, says that no legal recourse is available to stop the project: "Congress took that away. All we can do is mourn the day this thing gets built."