Cal. Sts. & High. Code § 10210

To expedite the conduct of proceedings and the making of any acquisition or improvement authorized by this division the legislative body may at any time transfer into a special fund designated by the name of the improvement proceeding, out of any available funds of the municipality, such sums as it deems necessary. The sums so transferred are a loan to the special fund, and shall be repaid out of the proceeds of the assessments provided for in this division.