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HomeMy WebLinkAbout4_14_21 TAC Minutes Summary Final Technical Advisory Committee (TAC) Meeting 1:00 P.M. – Wednesday, April 14, 2021 Mendocino County Department of Transportation 340 Lake Mendocino Drive, Ukiah CA, 95482 Virtual Meeting via Zoom Supporting Documents: April 14, 2021 Agenda UVBGSA TAC Presentation March 10, 2021 Minutes Summary Meeting Summary Call to Order and Roll Call TAC Members Present: Laurel Marcus, Beth Salomone, Sean White, Mike Webster, Ken Todd, James Linderman Absent: Levi Paulin, Javier Silva All Others Present: Meeting Called to order at 1:05 PM Approval of Meeting Summary from the March 10, 2021 Meeting Committee Action: Motion to approve the minutes from the March 10, 2021 TAC Meeting, Call for Motion by Beth Salomone, Motion made by Laurel Marcus Motion carries to approve meeting summary from March 10, 2021 meeting. No Comments Discussion Regarding Finalized Integrated Model Results Presenter(s): Laura Foglia, Amir Mani, Larry Walker and Associates Introduction: Finalize Lowering Groundwater Levels and Depletion of Interconnected Surface Water Sustainable Management Criteria Agree on the approach to identify the scenarios for these two scenarios to begin writing text Exploratory Scenarios No Historical Supply Business as Usual 2x the pumpage Worst for GW Elevation No Lake Mendocino Releases River Leakage Aquifer is disconnected between the north and the south. Redwood Valley is very sensitive to Russian River Flows Central/Southern Ukiah As long as Lake Mendocino is releasing no matter what pumpage you have you will meet diversion demand. Aquifer cannot make up the diversion from Lake Mendocino This data is average over the year type e.g. Dry 2014/2015, Critical 2015 When you have 2x pumping there is no recharge from the river. Streamgage Flow Hopland Gage Historical and 2x pumpage is similar to normal. Without Release, there is no flow to Hopland Talmage Gage When you double the pumpage you drain the aquifer 12-15 ft If you keep the release the same and double pumpage you have a ~2 cfs decline out of about 80 cfs. Gaining/Losing Conditions of the River Tributaries data is sparse but based off elevation, they will be mainly losing water to the aquifer or dry. Russian River in Redwood Valley is almost always losing to aquifer. In Calpella through spring, the Aquifer is gaining from River September, 2014 Scenario No Demand: Russian is losing until south of the Treatment Plant at the incision area 2x pumpage – Main time almost the whole Russian is dry September, 2016 Wet Year More Dry River Scenarios Our Flows are great, Model is very important for understanding the uncertainty but can be used as a tool now to help understand the dynamics. Rearranging pumpage can resolve a lot of these timing issues and could help solve a lot of the issues we are currently facing. Discussion: Amir Mani: Some demand such as Ag and Municipal Diversions are not met in dry years because there is no water in the river Stephen Maples: No release scenario, are SW diversions met by groundwater pumping? Amir Mani: Currently GW replacements for no SW are not currently included in the model. Stephen Maples: Averaging over the year hides summer dry month and the No Demand/Critical WY is quite a bit higher? Amir response needs to check back in. Devon Jones: All Ag surface water diverters do not have the same ability to pump their diversion from GW Amir: We took an adjustment that the Ag members have 30-40% ability to pump their GW based off of their SW diversion. If we know the specific parcel information then we are able to build that into the Ag Package. Zac Robinson: Looks like RV is very fragile. Very sensitive to high pumping scenarios. Amir Mani: More uncertainty in Redwood Valley because of poor data. RV shows more sensitivity than other parts of the basin and we need to treat it as a separate part of the basin. Zac Robinson: 2 CFS comes from what quantity? Amir Mani: 2 CFS out of roughly 80. River is sensitive to releases and diversions not sensitive to GW pumpage. Laura Foglia; If we have a wet year like 2017, there is a strong recharge back to almost normal levels. Very reactive system. Stephen Maples: Reach/Loss Estimates by Jason showing net loss section south of Lake Mendocino ~60 cfs and can be used to compare to the model as a calibration point. Amir Mani: We have no diversion data in Jason’s estimates and the model estimates it with diversion data. Devon Jones: Impervious/Pervious Soils – Goal in Ag not to use more water than beyond the root zone but is it being considered? Amir Mani: We have been building the soil database into the model and besides Ukiah, most of the basin is pervious. Applied water is water taken up by Crop not goes into the Aquifer. Any pumping water applied to Crops is not double counted into aquifer recharge. Committee Action: None Discussion Regarding Strawman Approach to Setting Sustainable Management Criteria Presenter(s): Laura Foglia, Larry Walker and Associates. Introduction: Based off Model Scenarios current GW Level SMC are attainable MO >25% of Historic Record Action Trigger: Historic Low at Spring WL – 2 Consecutive years MT: 10 or 20 % of max historic depth to water or 10 ft Signal in the Watershed is clear from Spring Water Level to engage PMA’s/Actions The only historical record (>6 yrs) are three wells but will be built out over the course of the plan Forecasted Well Failure – Wells going dry On return to Fall 2016 Wells – 2/3% of Wells will go dry depending on 31/40 yr retirement age. Well Replacement Costs 200-300 thousand dollars On return to Fall 2016 Wells Minus 10 Ft – 5/9% of Wells will go dry depending on 31/40 yr retirement age. Most wells dry will be in Redwood Valley 3-8 Hundred Thousand dollars On return to Fall 2016 Wells Minus 20 Ft – 9/12% of Wells will go dry depending on 31/40 yr retirement age. Still most wells dry will be in Redwood Valley .4-1.2 Million dollars Impact on GDE’s Most of the GDE’s are along the Russian River. GDE’s in Redwood Valley is a weak spot but current SMC levels will be protective of GDE’s along Russian Impact on Interconnected Surface Water Depletion Need to provide Map of Interconnected areas (Disconnected/Interconnected) For SGMA management – Russian needs to stay connected. Tributaries are not as important to keep connected due to their ephemeral nature. Russian is considered Gaining or Losing Connected, Tributaries are considered Losing Disconnected. ISW Depletion Metric Currently using GW Elevation as a proxy Transects will create: ISW SMC = f(GWL) + f(Measured/Modeled GW contribution from Transect data) Better data will be provided in 5 years. Takeaways GW Level MT No ISW Depletion, Loss of GDES, # of wills impacted Any Lower than 2015 – Lower MT needs to be proved will not impact other ISW/GDE & Beneficial Users Discussion: Sean White: Given how prone Redwood Valley is to these dry well issues what can we do about it and how responsible are we for it as a GSA? Beth echoed the same questions Laura Foglia: Possibility to mention in GSP, a separate management action set for Redwood Valley. While it is a more climate related issues it is still part of the basin. Zac Robinson: Wells don’t fail in wet years they fail in dry years. Laura Foglia: Well replacement failures are not included in first round of GSP’s so DWR says the costs and analysis needs to be included. Laurel Marcus: Redwood Valley Recharge Ponds? Laura Foglia: That would be a great place to identify a management action to build them there as that is the most water scarce area. Stephen Maples: Comment on Minimum Threshold, more representative to add a buffer to the 10% depth to GW. Seems like 10% of total depth to water is significant. Sonoma County basins, choosing not to go below historical minimum. Using an average of three dry years. Sonoma Water wants GSA to stay within historical minimums. Laura Foglia: Going low enough to not catch the minimum for wells close to the river. Wells further from the river presents more uncertainty. Being more conservative at wells near the river will be enough. The 2-5 ft of possible decline by the river is the difference between the continuous measurements. Coordinate approach to Sonoma Water Devon Jones: Looking at the specific wells impacted in RV. Are they active? What other options are available for replacement/individuals. Need to do ground-truthing to truly ascertain the impact. Laura Foglia: The well points should show the active wells. Need to work with on ground members to ascertain active wells. Beth Salomone: Second Devon’s point. Is this action to create a map a PMA? Is it outside GSA authority to register Groundwater Wells? Can we focus it in the RV area since it is the high risk area to help mitigate uncertainty? PMA’s are super important to build out capacity especially in these dry years. View it from the lens as protect our basin from occasions like this year. Laura Foglia: Creating Management Action to better understand what is happening in RV. Start with watershed coordinator with Barry and then make it a Management action. Capital projects will get funding but small targeted actions will get funding especially for dry years. Capital projects such as recharge will bring funding to help fund satellite projects such as ground-truthing. Sean White: Hard to do recharge in RV because there is no starting water levels. Potential to use Natural Winter Water Laura Foglia: We have data gaps but we can make that work. We need to be aware of what you guys want for scenarios. Ex. 1.5x GW Pumping to create a scenario as well as Management actions for PMA chapters. Devon Jones: How to account for Illicit GW pumping and Trucking of water from one resource to another. Beth seconds that and wants to add in PMA to discuss that. James Linderman: Run multiple Project Scenarios in RV area on water levels to see if one project offers better bang for our buck. Or if GW in the RV area should be used extensively. Can we artificially repair the areas in the model. This will also have to be a living document documenting change. Laura Foglia: Redwood Valley would be high on the DWR priority list to get funding for a project. Anything we can get funded for RV will benefit the whole basin. Other basins are working on a conservation model that for those who conserve 10% of their water to not pay GSA fees/taxes for those that have it. Committee Action: None Discussion Regarding Present and Future Water Budget Discussion was moved to May TAC meeting Action Items and Closing Comments 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. Adjournment Meeting Adjourned at 3:19 PM