(a) Eligible activity shall mean a project proposed by the legislative body of a city as set forth in its application pursuant to section 813.5. Such proposal shall indicate clearly, definitively and in such detail as may be required by the commissioner, the scope of the proposed project which shall in the judgment of the commissioner have a significant impact on the city government.

(b) A city which has commenced an eligible activity on or after January 1, 1971 shall be eligible for reimbursement up to a limit of 40 percent of authorized charter expenditures or $25,000, whichever is less. Such city shall not be eligible for reimbursement for more than one project during a period of 10 years computed from the date of any prior reimbursement pursuant to this program.