Public Resources Code § 49131

The district board may designate any depository for the custody of any or all the money collected or received for district purposes pursuant to Article 2 (commencing with Section 53630) of Chapter 4 of Part 1 of Division 2 of Title 5 of the Government Code.

A depository shall give security sufficient to secure the district against possible loss and shall pay the warrants drawn by the district for demands against the district under the rules that the district board prescribes.