For the purpose of establishing and designating the official grades of the streets, alleys and sewers of the City of Anaheim, the North American Vertical Datum of 1988 (NAV88) is hereby declared to be the "Datum Plane" of the City of Anaheim. The City of Anaheim has established, and maintains, a network of benchmarks throughout the City, which are to be used for purposes of vertical control. (Ord. 98 § 1; July 10, 1894; Ord. 5855, § 29; April 29, 2003.)