It's obvious you didn't read the article I posted. Here's the part you missed:
A parallel statute,
<33 U.S. Code § 2293, allows the secretary, during such a declared emergency, to redirect “the resources of the Department of the Army’s civil works program, including funds, personnel, and equipment, to construct or assist in the construction, operation, maintenance, and repair of authorized civil works, military construction, and civil defense projects that are essential to the national defense.”
The money would not come from the Treasury but from already appropriated funds within the Dept of Defense.
The DoD gets around $100 billion/yr to use on construction projects. Diverting $5 billion of unspent funds is easy.