Barriers Along the U.S. Borders: Key Authorities and Requirements

Summary

Securing the borders is an issue of perennial concern to Congress. Federal law authorizes the Department of Homeland Security (DHS) to construct barriers along the U.S. borders to deter illegal crossings. DHS is also required to construct reinforced fencing along at least 700 miles of the land border with Mexico (a border that stretches 1,933 miles), though Congress has not provided a deadline for its completion. At this time, fence construction has largely been halted, though DHS still needs to deploy fencing along nearly 50 additional miles of the southwest border to satisfy the 700-mile requirement.

The primary statute authorizing DHS to deploy barriers along the international borders is Section 102 of the Illegal Immigration Reform and Immigrant Responsibility Act of 1996 (IIRIRA; P.L. 104-208, div. C). Congress made significant amendments to IIRIRA Section 102 through three enactments—the REAL ID Act of 2005 (P.L. 109-13, div. B), the Secure Fence Act of 2006 (P.L. 109-367), and the Consolidated Appropriations Act, 2008 (P.L. 110-161, div. E). These amendments required that DHS construct hundreds of miles of new fencing along the border, and also provided the Secretary of DHS with broad authority to waive “all legal requirements” that may impede construction of barriers and roads under IIRIRA Section 102. These statutory modifications, along with increased funding for border projects, resulted in the deployment of several hundred miles of new barriers along the southwest border between 2005 and 2011. In recent years, DHS has largely stopped deploying additional fencing along the border, as the agency has altered its enforcement strategy in a manner that places less priority upon fencing.

As amended by the Secure Fence Act in 2006, IIRIRA Section 102(b) required DHS to install at least two layers of reinforced fencing along five stretches of the southwest border totaling more than 700 miles. IIRIRA was substantially revised just over a year later by the Consolidated Appropriations Act, 2008, to replace this requirement with a mandate that DHS install reinforced fencing (but not necessarily in two or more layers) “along not less than 700 miles” of the border.

Section 102(b) provides that “notwithstanding” this requirement, DHS is not legally obligated to install fencing at “any particular location.” One way to construe this clause is simply to indicate that, while DHS is required to install fencing along at least 700 miles of the border, it is not required to install any portion of the mandated fencing at any specific location (in contrast to the earlier requirement of the Secure Fence Act). An alternative interpretation of this clause has also been suggested (including by some DHS officials, but not consistently), under which DHS could potentially construct fencing along less than 700 miles of the border and satisfy the statute’s fencing requirements, if it determined additional fencing to be unwarranted. This broad interpretation of the clause seems problematic, however, as it would render Section 102(b)’s provision requiring fencing “along not less than 700 miles” of the border meaningless. The legislative history behind the changes made to IIRIRA Section 102(b) also favors the narrower interpretation. Legislation in the 114th Congress, including H.R. 399, the Secure Our Borders First Act of 2015, as reported by the House Homeland Security Committee, would effectively mandate the completion of the remaining mileage and also provide additional fencing specifications.

This report discusses key statutory authorities and requirements governing DHS’s construction of barriers along the U.S. borders. It also includes appendixes listing federal laws that have been waived by DHS in furtherance of border construction projects. For more extensive discussion of ongoing activities and operations along the border between ports of entry, see CRS Report R42138, Border Security: Immigration Enforcement Between Ports of Entry, by Lisa Seghetti.