Military Construction Funding in the Event of a National Emergency [Updated January 11, 2019] [open pdf - 537KB]
"The President's reported consideration of whether to invoke various statutory authorities (including some triggered by a declaration of a national emergency) to direct the Department of Defense (DOD) to construct 'a physical barrier' along the U.S.-Mexico border has raised questions about potentially available appropriated funds. This Insight identifies previous military construction projects funded through emergency authorities and unobligated military construction funding balances. Title 10 U.S.C. Section 2808 is entitled Construction authority in the event of a declaration of war or national emergency and depends upon a 'declaration of war or the declaration by the President of a national emergency in accordance with the National Emergencies Act [NEA] (50 U.S.C. 1601 et seq.) that requires use of the armed forces.' A declaration by the President under the NEA must detail the statute under which action will proceed."
CRS Report for Congress, IN11017
Congressional Research Service: https://crsreports.congress.gov/