Section 10724 Of Chapter 4. Establishing Groundwater Sustainability Agencies From California Water Code >> Division 6. >> Part 2.74. >> Chapter 4.

. (a) In the event that there is an area within a high- or medium-priority basin that is not within the management area of a groundwater sustainability agency, the county within which that unmanaged area lies will be presumed to be the groundwater sustainability agency for that area.
  (b) A county described in subdivision (a) shall provide notification to the department pursuant to Section 10723.8 unless the county notifies the department that it will not be the groundwater sustainability agency for the area. Extractions of groundwater made on or after July 1, 2017, in that area shall be subject to reporting in accordance with Part 5.2 (commencing with Section 5200) of Division 2 if the county does either of the following:
  (1) Notifies the department that it will not be the groundwater sustainability agency for an area.
  (2) Fails to provide notification to the department pursuant to Section 10723.8 for an area on or before June 30, 2017.