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Home My WebLink AboutTAC Minutes 9_09_20Technical Advisory Committee (TAC) Meeting 1:00 P.M. – Wednesday, September 9th, 2020 Mendocino County Administration Center, 501 Low Gap Road, Room 1010, Ukiah CA 95482 Virtual Meeting via Zoom Supporting Documents: Agenda UVBGSA TAC Presentation Meeting Summary CALL TO ORDER – ROLL CALL Present: Glenn McCourty, Sean White, Beth Salomone, Ken Todd, Mike Webster, Laurel Marcus, Stephen Maples, Deborah Edelman and Don Seymour Absent: Sonny Elliot, Jr, Levi Paulin Approval of Meeting Summary from the May 13, 2020 Meeting Presenter/s: Sarah Dukett, Mendocino County Water Agency Committee Action: Motion by Beth Salomone, seconded by Laurel Marcus. Motion carries to approve meeting summary from May 13, 2020. Discussion and Possible Action Regarding Updates to the Monitoring Network Including Instrumentation of Existing Wells, New Stream Gages and Technical Support Services Presenter/s: Laura Foglia, Larry Walker and Associates; Amir Mani, Larry Walker and Associates Introduction: Well Monitoring Will be implemented for the 20 year GSP Horizon CASGEM/Elevation Data will be used as well as introduction of Continuous Well Monitoring Software Instrumentation of Existing Wells South Central #1-a 5 wells available for monitoring including two at the treatment plant which are used for GW recharge 3 are in discussion of being drilled/monitored North Central #1 Eastside: Looking for Existing Well to instrument or permission to drill a new well Westside: Two currently available CASGEM Wells, to be instrumented once well pair is found on Eastside Redwood Valley Eastside: Verbal Agreement to instrument an existing GeoTrackr Well Westside: Two CASGEM wells exist, one further well site exists and need to obtain permission from School District or drill new well New Streamflow Gage Installation Redwood Valley on Russian River Will replace NFMS gage Forsythe Creek Will be used as a model tributary for UVBGSP Discussion: Other Areas to add to GW/SW Monitoring Upstream and Downstream of Alluvial Basins to assess how much water is lost to the Basin Possibility of adding gages above CSLI gages to assist with that data collection Priority Tributaries for Streamflow Measurement Mill Creek and Powell Creek Committee Action: Comments to staff regarding potential areas to look into for wells and stream gages. Discussion Regarding an Introduction to Possible Geophysical Studies that Facilitate Management Actions Presenter/s: Brad Gooch, Larry Walker and Associates & UC Davis Introduction: Three Different Monitoring Technologies for Assessing Defined Areas of Aquifer Recharge Towed Time-Domain Electromagnetics (tTEM) An ATV will tow a transmitter and GPS at speed to determine areas of high and low conductivity. High conductivity will indicate areas of clay soil beneficial for aquifer recharge. Can rapidly cover large amounts of distance creating a soil profile at 150-200 ft bgs. Can be applied to a variety of topographic situations including wineries, farmland and orchards. Hand Carried Time-Domain Electromagnetics (WalkTEM) A 130ft2 grid will be laid out by hand providing a soil profile 800-1000 ft deep. 10-15 soundings can be completed in a day. Electrical Resistivity Imaging/Tomography (ERI/T) DC Current is channeled along 1300 ft cables to provide a transect of soil profile up to 200 ft bgs. Allows understanding of shallow subsurface soil-hydrology to characterize ecosystem health using GDE’s as indicators. Discussion: Large areas of UVB floor is suitable to tTEM/ERI/T which can show best GW storage locations, recharge areas and places for pilot studies especially with a growing urban population. Information can be applied to hydrogeology models. Possibility of taking water out of Russian River in the winter to lay over fields designated as recharge areas. Committee Action: None. Discussion Regarding the Development of GSP Chapters and Upcoming Opportunities for Review Presenter/s: Laura Foglia, Larry Walker and Associates; Amir Mani, Larry Walker and Associates Introduction: GSP should be drafted by early summer 2021 Sections will be rolled out Monthly for review by TAC and Public Comment Ch. 1 – Administrative Ch. 2 – Plan Area and Basin Setting September End 2.1 & 2.2 delivered to TAC Needed for 2.1 Existing GW Monitoring and Management Programs Incorporate County of Mendocino Zoning Plan and Policies for Construction/Destruction and Wellhead Protection Any migration of contaminated GW or GW Replenishment and all county water projects need incorporation Develop Groundwater Dependent Ecosystems Needed for 2.2 Interconnected Water Systems & GDE’s need technical work October – Water Quality & Subsidence November – Surface Water Depletion January – Lowering GW Levels and Decrease in Storage Committee Action: None. Discussion and Possible Action Regarding Integrated Model Updates and Preliminary Water Budget Presenter/s: Laura Foglia, Larry Walker and Associates; Amir Mani, Larry Walker and Associates Introduction: GSFLOW Three stream gages added. Four updated channel characterizations. Three Aquifers defined allowing different values to better define and calibrate model. Key Point: Assessment of need to add Ag Package after continuing calibration. Water Budget Past 50 Years of Precipitation characterized for baseline 5 years have been Critically Dry Quantiles: 0.1, 0.35, 0.5, 0.75, 1 Critical, Dry, Below Normal, Above Normal, Wet Water Budget with model provides month to month inflows and outflows into the system for each of the quantiles. Currently does not include Ag package. Water Budget in GSP will give Dry/Normal/Wet years as overview. Majority of graphs will go in appendix. Future Baseline and Climate Change Scenarios Future hydrological predictions must be based on 50 years of historical baseline. DWR will provide moderate and extreme Temperature and Precipitation scenarios for 2030/2070 based on Global Climate Models and Representative Concentration Pathway models. GCM-RCP Models are using 1915-2011 data at a 6 km scale to produce 2030/2070 change factors which are multiplied by baseline Precipitation and EvapoTranspiration to get climate data for the UVB. Limitations of DWR Method The model produces results best interpreted as trend and magnitude of changes. Hard to interpret as a time-series due to the high interannual variability of climate in CA so any historic interannual variability will be reflected in future predictions. Model mirrors historical trends but Climate Change will change that trend Graphs will show a shift in Climate/ET/Precipitation not the yearly increase. Climate Change Impacts Based on DWR Factors Precipitation looks to increases in long term due to increased intensity, possibility of decreased rainfall events. Evapotranspiration looks to be increasing in the future across every month. Detailed changes will be presented when model is run. Discussion: Streamflow In/Out of Watershed is incorporating Evaporation/Transpiration as calculated by Model. Recommended we follow DWR Climate Change approach to avoid unnecessary scrutiny and other models can be pursed separately. Necessary to work with stakeholders to create UVB management plan for future scenarios. Necessary to account for the fact that the timeline for a majority of rainfall will start to arrive in days and weeks instead of months and how that is absorbed/runsoff. Summary: If Management Plan is based on a Water Budget, DWR methodology will be useful. If Management Plan is based on when rainfall arrives, development of other methods will be necessary. Committee Action: Review characterization of Dry/Wet years as this would change aggregate water budgets. Discussion and Possible Action Regarding Scenario Development Survey and Simulated Future Scenarios Presenter/s: Laura Foglia, Larry Walker and Associates; Amir Mani, Larry Walker and Associates Introduction: Future Baseline Repeat most recent 10 year period given the drought conditions instead of a 50 year baseline Develop simulations of the other scenarios using climate change data as another option to DWR methods Changes to Potter Valley Project Plan for 50% reduction to complete loss of inflows To be planned for starting in 2030 Plan for water availability changes with Lake Mendocino outflows Changes in Land Use Addition of Cannabis Farms, +20% Vineyards Increased population growth, Areas of population growth and increased water use Water Use/Storage/Recharge Growth of Recycled Water within City New Stormflow Recharge/Capture Zones to adjust to higher rainfall events Changes in storage methods, converting high use wells to ponds Resiliency of GW to refilling, 5-20 year drought Discussion: Potter Valley Project How water rights will change for the valley in the coming years is up for discussion and necessitates a separate meeting Committee Action: Create a separate TAC Working Group to focus exclusively on the outcomes for the Potter Valley Project and Potter Valley Project model scenarios. Discussion and Possible Actions Regarding the Use of Satellite Imagery for Evaluation of Surface Water/Groundwater Interaction and Groundwater Dependent Ecosystem Presenter/s: Rich Pauloo, Larry Walker and Associates Introduction: River Connectivity Satellites can show instances when a creek is/isn’t flowing and the time it went by can be estimated between the dates the photos were taken. 40 Observation sites. 3 on Russian River West Fork 1 on Russian River East Fork 36 on Tributaries ~ 2 per Tributary Initial Evaluation Provides Flow/No Flow designation for each of the observed streams during each of the year types: Dry, Normal, Wet, Generally Satellite Imagery Sources Google Earth High-Res images, random months or skips years Not usable for pinpointing on a sub-monthly scale when rivers go dry Sentinel Low-Res images, hard to pinpoint a majority of streams Twice or more per month Plant High res images, can be contracted to take pictures at predefined intervals to identify when streams run dry Only available from 2017 onwards Two Tier Monitoring Approach Tier 1 – Stream Disconnect Monitoring (Planet 50 cm resolution) Can identify small riparian corridors and identify what month they go dry Tier 2 – Classifying Seasonal Changes to GDEs (PS4 4-3m Resolution, verified by Planet data) Create a Fall Baseline year and check each year the change in NDVI Identify how the GDEs change year on year Utilizing NDVI and unsupervised classification land cover maps allows effective and cheap estimation of riparian ecosystem health Allows observation of health of GDEs to better understand how groundwater is flowing when streams are dry Discussion: This in conjunction with Photo Point Morphology from citizen scientists allows an inexpensive and visual series of the health of the river and ecosystems. Committee Action: None Action Items and Closing Comments Presenter/s: Sarah Dukett, County of Mendocino, Laura Foglia, Larry Walker and Associates Introduction: Proposed Upcoming TAC meetings October 14th at 1 PM November 18th at 1 PM Creation of 1 on 1 Stakeholder Meetings Will allow Consultants and County Officials to better source stakeholder opinion on the varieties of issues presented in the GSP Committee Action: TAC consensus to set the next two TAC meetings for October 14 at 1pm and November 18 at 1pm. Public Comments on Items Not on the Agenda Public Comment: None. Adjournment The meeting adjourned at 4:15 pm. ________________________________ Glen McGourty, Chair Attest: Sarah Dukett UVBGSA Plan Manager / ________________________________