Public Resources Code § 8859
CHAPTER 3. Geodetic Datums and the California Spatial Reference Network
The geodetic control stations within the State of California having orthometric heights determined by differential leveling survey methods and conforming to all of the following requirements shall be part of the CSRN. The orthometric heights shall:
(a) Be referenced to NAVD88.
(b) Be published by NGS or CSRC.
(c) Have a NGS or CSRC published accuracy of third order, class II or better as defined by FGCS.