HydroVis Summarizing Technical Aspects of Inadequacies in 2023 DWR Determinations on Re-Submitted 2020 GSPs by Kait Palys/INTERA, Lisa Porta, Montgomery & Associates, Abhishek Singh/INTERA Introduction/Background
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Common Themes from Approved Re-submitted Plans The key themes from the approved re-submitted GSPs are summarized below:
SGMA Planning hit key milestones when all Groundwater Sustainability Agencies (GSAs) submitted their Groundwater Sustainability Plans (GSPs) by their respective deadlines - 46 GSPs for the critically overdrafted basins were submitted by January 31, 2020, and 65 GSPs in high/medium priority basins were submitted by January 31, 2022. The California Department of Water Resources (DWR) released their review of the 2020 GSPs in late 2021 and early 2022. Of these GSPs, five were approved and 13 were deemed incomplete [see table]. A Spring 2022 HydroVisions article summarized key takeaways from these reviews1. The incomplete GSPs had 180 days to re-submit their revised GSPs to correct deficiencies identified by DWR in their determination letters. In early 2023, DWR released their determinations on the re-submitted GSPs2, six of which are now considered inadequate and could go under State intervention, overseen by the State Water Resources Control Board (State Board) under SGMA.
• Intra-basin coordination: The approved subbasins were ostensibly more coordinated than most of the inadequate subbasins, both in methodology and report format. Five of the six approved basins submitted a single GSP. The approved Kings Subbasin submitted multiple GSPs that maintained a consistent report format and singular methodology for water budgeting and Sustainable Management Criteria (SMC).
In this article, we take a look at the current status of GSP determinations for the re-submitted GSPs and what key technical deficiencies still need to be addressed according to DWR’s review of the GSPs. We also summarize next steps for the “inadequate plans” and how the State Board might intervene in these basins.
• Consistent and quantitative SMC methodology: The approved re-submitted 2020 GSPs made significant updates to their measurements of sustainability, notably clarifying how the quantitative metrics consider potential significant and unreasonable impacts to beneficial users. In some cases, this update required the subbasins to significantly change their SMC methodology and MTs and measurable objectives to be more protective of the beneficial users that are most vulnerable to the chronic lowering of groundwater levels.
2023 Summer Issue
• Consideration of impacts to drinking water: DWR’s prior evaluation of the 2020 GSPs emphasized the minimum thresholds (MTs) for chronic lowering of groundwater levels did not sufficiently consider domestic wells in the inadequate GSPs. The recently approved re-submitted GSPs made notable improvements to their stakeholder outreach and data inventory to refine MTs that minimize, avoid, or mitigate impacts to domestic wells.
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