40 U.S.C. § 3502: Planned public works

to encourage public agencies and Indian tribes to maintain at all times a current and adequate reserve of planned public works the construction of which can rapidly be commenced, particularly when the national or local economic situation makes that action desirable; and to help attain maximum economy and efficiency in the planning and construction of public works. A public agency or Indian tribe shall use an advance under subsection (a) to aid in financing the cost of feasibility studies, engineering and architectural surveys, designs, plans, working drawings, specifications, or other action preliminary to and in preparation for the construction of public works, and for construction in connection with the development of a medical center, a general plan for the development of the center. An advance under subsection (a) does not commit the Congress to appropriate amounts to assist in financing the construction of any public works planned with the aid of that advance. Outstanding advances to public agencies and Indian tribes in a State shall not exceed 12.5 percent of the aggregate then authorized to be appropriated to the revolving fund established under section 3503 of this title . the project is planned to be constructed within or over a reasonable period of time considering the nature of the project; the project conforms to an overall state, local, or regional plan approved by a competent state, local, or regional authority; and the public agency or Indian tribe formally contracts with the Federal Government to complete the plan preparation promptly and to repay part or all of the advance when due. The Secretary may prescribe regulations to carry out this chapter.