Cal. Pub. Res. Code § 4594.6

Notwithstanding any other provisions of this chapter, if a registered professional forester certifies by written declaration, on behalf of the timber owner or operator, that the nonindustrial timber harvesting notice conforms to, and meets the requirements of, the approved nonindustrial timber management plan under which it is filed, timber operations may commence immediately unless the notice has been filed by mailing, in which case operations may commence three days after the notice has been mailed.