Cal. WAT § 1051.1

(a) In conducting an investigation or proceeding specified in Section 275 or 1051, or in Article 7 (commencing with Section 13550) of Chapter 7 of Division 7, the board may inspect the property or facilities of any person or entity to ascertain whether the purposes of Section 100 and this division are being met or to ascertain compliance with any permit, license, certification, registration, decision, order, or regulation issued under Section 275, this division, or Article 7 (commencing with Section 13550) of Chapter 7 of Division 7.

(b) If consent to inspect is denied or otherwise withheld, the board is authorized to obtain an inspection warrant pursuant to the procedure set forth in Title 13 (commencing with Section 1822.50) of Part 3 of the Code of Civil Procedure for purposes of an inspection under this subdivision. However, in the event of an emergency affecting the public health or safety pertaining to the particular site under which the inspection is being sought, an inspection may be performed without consent or the issuance of a warrant.

(c) The board may participate in an inspection of an unlicensed cannabis cultivation site conducted pursuant to a warrant duly issued pursuant to the Penal Code when requested by the party seeking that warrant for unlicensed cannabis cultivation and its associated activities that may involve a violation of this code, including, but not limited to, diversion or use of water in violation of this division or of any principles and guidelines established by the board pursuant to Section 13149.