In medium and high priority basins, including the Napa Valley Subbasin, GSAs must develop and adopt a Groundwater Sustainability Plan (GSP) with coordination agreements, or other agreements, as needed, for sustainable management of the basin by January 31, 2022. GSAs in critically overdrafted basins were required to complete their GSPs by January 31, 2020. The GSAs have 20 years following the relevant deadline for GSP adoption to achieve the sustainability goal for their basin, including avoidance of undesirable results.