California Code, Water Code - WAT § 537.2

(a) A final occupancy permit for a building shall not be denied by a local building official if water submeters or meters have not been installed for each residential unit as required by this chapter if the building owner can demonstrate either of the following:

(b) After issuance of the occupancy permit, the owner shall demonstrate that the submeters are installed in the building within 120 days of approval by the county sealer.