It is illegal to annoy passersby on sidewalks with a revolving water sprinkler.
Background information (if available):
5-9-2: Lawn Sprinklers
No person shall place any revolving fountain, hose or lawn sprinkler so that the water from the same shall be thrown upon any street or sidewalk to the annoyance of passersby, and no person shall cause water to flow over or upon any street or sidewalk. (1979 Code)