Dependent special districts are governed by a board that serves at the pleasure of a city or county. Board members may be ex officio, serving on the dependent special district board by virtue of — and contingent upon — their service in another office. They may also be appointed to “unfixed” terms, allowing the appointing body to replace them at any time, rather than serving a fixed term, such as four years. City councils and county boards of supervisors often appoint themselves to these positions.