CA Gov't Code Section 92307

All money received pursuant to this title, whether as proceeds from the sale of bonds, notes, or other evidences of indebtedness or as revenues, shall be deemed to be trust funds to be held and applied solely as provided in this title.

Any bank or trust company with which the money is deposited shall act as trustee of the money and shall hold and apply it for the purposes hereof, subject to the resolution authorizing the bonds of any issue or the trust agreement securing the bonds may provide.