California Code, Government Code - GOV § 61103

(a) A district that acquires, constructs, improves, and maintains streets, roads, rights-of-way, bridges, culverts, drains, curbs, gutters, sidewalks, and any incidental works pursuant to subdivision (l) of Section 61100 shall have the powers, duties, and authority of a county for those works, including, but not limited to, the following:

(b) A district shall not exercise those powers, duties, and authority for any of those works if it is owned by another public agency unless that other public agency gives its written consent.