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Home My WebLink About5_19_21 TAC Minutes Summary DraftUKIAH VALLEY BASIN GROUNDWATER SUSTAINABILITY AGENCY 340 Lake Mendocino Dr.  Ukiah  California 95482  (707)463-4363  fax (707)463-5474 1 Technical Advisory Committee (TAC) Meeting 1:00 P.M. – Wednesday, May 19, 2021 Mendocino County Department of Transportation 340 Lake Mendocino Drive, Ukiah CA, 95482 Virtual Meeting via Zoom Supporting Documents: • May 19, 2021 Agenda • UVBGSA TAC Presentation  April 14, 2021 Minutes Summary Meeting Summary 1. Call to Order and Roll Call TAC Members Present:, Beth Salomone, Mike Webster, James Linderman, Barry Hill (for Laurel Marcus), Levi Paulin, Sean White Absent: Javier Silva, Laurel Marcus, Ken Todd All Others Present: Al White, Don Seymour, Barry Hill, Amir Mani, Laura Foglia, Amber Fisette, Deborah Edelman Meeting Called to order at 1:05 PM 2. Approval of Meeting Summary from the April 14, 2021 Meeting Committee Action: Motion to approve the minutes from the March 10, 2021 TAC Meeting, Call for approval by Beth Salomone, Motion made by Levi Paulin, Seconded by James Linderman with Mike Webster abstaining. Motion carries to approve meeting summary from March 10, 2021 meeting. No Comments 3. Discussion Regarding Simulated Future Scenarios Presenter(s): Laura Foglia, Amir Mani, Larry Walker and Associates Introduction:  TAC Members have received and are reviewing Chapters 3 and 4  Presentation from April 14 has incorrect model numbers and those were updated for this meeting  Focus on this meeting will be CVD releases and PVP UKIAH VALLEY BASIN GROUNDWATER SUSTAINABILITY AGENCY 340 Lake Mendocino Drive  Ukiah  California 95482  (707)463-4363  fax (707)463-5474 2 o Sonoma Model who provided the data do not use the same climate model as UVBGSA is using o Sonoma also uses leakage and diversion models that estimate differently than GSFLOW  Four Scenarios o Recycled Water o PVP Run of River o PVP Modified o PVP Decommissioned  River Leakage – Dry Season (May-Sep) o North Ukiah – Overall Loss of AF in Russian River o Central - Loss of Water in PVP RoR and PVP Mod scenario o South – Gain in every scenario o Disconnected Aquifer systems apparently  River Leakage – Wet Season (Oct-Apr) o North – Loss in most scenarios o Central/South – Gain in every option except PVP RoR  Hopland/Talmage Flow o Groundwater heads do not change w/ or w/o releases. We see more difference with diversions  GWE at RMP’s o Greatest Fluctuation from Run of River scenario. Other scenarios do not create as much variation in North/South Ukiah  Gaining/Losing Conditions of River o Northern Russian is always losing to aquifer o Only part of river that changes is in Central Ukiah  GW Elevation o 2x Pumpage depletes GW heads o Dry Critical Water Year do not deplete the heads below historical levels o Model will need refinement with next 5 years of data collection o Lower Flows expected to impact pumping but is important the pumping happens in robust aquifer areas if we continue to change diversions from Lake Mendocino. o Remember GSA responsibility is decline of SW due to Pumping. GSA only involves themselves if the water balance changes as a result different from any pumping actions. Discussion:  Sean White: Why is it gaining in Decommissioned Potter Valley but not Run of River or Modified  Amir Mani: Need to look into that more. Decommissioned provides good summer flow, need to look into model further.  Laura Foglia: We see good rebound in the different scenarios but are not seeing as much change in the groundwater level. This is going to be part of the calibration questions going further lacking more data.  Beth Salomone: What documents/information do we need to pull together for a working group meeting  Amir Mani: How would less water for diversions affect the ag producers . Currently we are converting Ag diversions to pumping but not all Ag producers have an ability to pump.  Laura Foglia: We know that we need more information but with long term monitoring we can build out the model further. UKIAH VALLEY BASIN GROUNDWATER SUSTAINABILITY AGENCY 340 Lake Mendocino Drive  Ukiah  California 95482  (707)463-4363  fax (707)463-5474 3  Don Seymour: The reason we are looking at the scenarios. If the PVP is decommissioned it is giving up 50-70 thousand AF from Lake Mendocino for fish flow on the Eel. Release changes are different because of the releases for fish flows from baseline. Modified Reasonable and Prudent Alternatives will increase water transfer. Committee Action: None 4. Discussion Regarding Current Status of GSP Technical Efforts Presenter(s): Laura Foglia, Larry Walker and Associates Introduction:  Gather agreement on how LWA is wrapping up Ch. 3&4  Draft will be ready for public review by end of July  5 main chapters plus multiple appendices  Sustainability Goal – Defining Goal of the GSA  Undesirable Results o As long as we don’t go below these levels by the end of the GSP we will have succeeded o Trigger is MT to implement PMA’s to prevent UR  Minimum Thresholds o Going to have different thresholds for wells close v far from the river o Shallow Well Protection analysis o ISW & GDE Impact Analysis  Minimum Threshold o Lowering GW Levels & Reduction of Storage  Max Historical Depth to GW  10% if correlated with Stream  20% not correlated with Stream or Max 10 ft  Goal is to keep Levels above historical minimum  Surface Water Depletion o Fiver years: MT GWE (imperfect proxy) o After: Volume of depletion at gages based on model calculations and transects o GSA has no responsibility if PVP operations change. Model is currently only dealing with pumping  Degrade Quality o Nitrate 10 mg/L o Specific Conductivity 900 us/cm  Measurable Objective and Interim Milestones o The drought is a critical emergency that would necessitate a drought management plan for funding o GWE/Storage – 75 Percentile of Historical Depth to Water o ISW – Will be defined under the concept of watershed goal o WQ – 75% of monitoring wells under 75 % of Regulatory objective Discussion: UKIAH VALLEY BASIN GROUNDWATER SUSTAINABILITY AGENCY 340 Lake Mendocino Drive  Ukiah  California 95482  (707)463-4363  fax (707)463-5474 4  Sean White: Think we need to include WCR as well as the correlation with the stream. Also domestic wells in Redwood Valley should not constrain the GSP as it is li kely an outlier.  Laura Foglia: The analysis was done with ¾ lower portion of the valley. We may create separate subsections of the Basin with Redwood Valley and in the rest of the valley.  Barry Hill: As long as 10 or 20 % is tied to something w e can see the ties to the real world.  Laura Foglia: If we use the 10% threshold in Redwood Valley it would be a protective measure  James Linderman: What are the wells being used for the RMP’s in the Lowering GW Levels and Reduction of Storage thresholds.  Amir Mani: The threshold is the baseline and 25% of the RMP’s fall below the MT for two consecutive years Committee Action: None 5. Discussion Regarding Projects and Management Actions and Current Drought Presenter(s): Laura Foglia, Amir Mani, Larry Walker and Associates Introduction: Discussion: Committee Action: Any PMA’s that the TAC members note should be sent to LWA 6. Possible Additional Discussion Regarding Sustainable Management Criteria (Time Permitting) Presenter(s): Laura Foglia, Amir Mani, Larry Walker and Associates Introduction: Discussion: Committee Action: None 7. Action Items and Closing Comments None. 8. Public Comments on Items Not on the Agenda This time is reserved for the public to address the Committee about matters not on the agenda and within the jurisdiction of the Advisory Committee. Persons wishing to speak on specific agenda items should do so at the time specified for those items. No Public Comment at this time. 9. Adjournment UKIAH VALLEY BASIN GROUNDWATER SUSTAINABILITY AGENCY 340 Lake Mendocino Drive  Ukiah  California 95482  (707)463-4363  fax (707)463-5474 5 Meeting Adjourned at 3:05 PM