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HomeMy WebLinkAbout3g Board Meeting_20201Feb11_FinalUkiah Valley Groundwater Sustainability Plan Development Update February 11, 2021 Ukiah Valley Basin Groundwater Sustainability Agency Board Meeting Draft Topic Agenda ◼Introduction to Projects and Management Actions ◼Update on GSP Monitoring Networks ◼Introduction to Interconnected Surface Water and Groundwater Dependent Ecosystems ◼GSP’s 3-month Outlook 2 Draft Introduction to Projects and Management Actions Draft Projects and Management Actions ◼Why do we need projects and management actions (PMAs)? ⚫To achieve the sustainability goal by 2042 and avoid undesirable results through 2092 ⚫To respond to changing conditions in the Basin ⚫Each of the PMAs may support achieving sustainability for one or more sustainability indicators ◼Can be categorized into ⚫Existing PMAs ⚫Proposed or planned PMAs to reach sustainability ⚫PMAs to be evaluated in the future 4 Draft Proposed PMAs in WG Meeting and Existing PMAs ◼Proposed Projects: ⚫Reduce evaporation losses in storage facilities ◼Use of WaterSavr for Lake Mendocino and agricultural ponds ◼Use shade ball cover for agricultural ponds ⚫Implement recharge projects ◼Using ag fields to recharge by utilizing frost protection systems and/or timely off-season diversions ◼Implement multi-benefit infiltration projects including stormwater BMPs and LIDs ⚫Protect source waters and recharge areas ◼Purchase surface water tributaries’ headwaters ◼Limit urbanization of recharge areas through working with land use planning agencies 5 ◼Existing PMAs: ⚫City of Ukiah RW project (Water Supply) ⚫PVP Project (Water Supply) ⚫Ukiah Valley-Redwood Valley Water Supply Reliability Intertie and Well Development Project (Water Supply) ⚫Forecast Informed Reservoir Operation (Water Supply) ⚫Water Main and Meter Replacement (Demand Management) ⚫Conservation ordinances and programs outlined in general plans and water plans ⚫Public education and outreach ⚫Improved frost and heat forecasting Draft Questions? Draft Update on GSP Monitoring Networks Draft GSP Annual Reporting Requirements 8 Directly or indirectly measured by the monitoring networks ◼Monitored data should be stored in the Data Management System and reported in the annual reports (April 1 of each year): ⚫Groundwater elevation data ◼Contour maps of at least seasonal highs and lows for each aquifer ◼Hydrographs with water year types from at least Jan 1 , 2015. ⚫Groundwater extraction ◼A table showing extractions by water use sector ◼A map showing general location of extractions ◼Surface water supply available for groundwater recharge or in-lieu use ◼Total water use by water use sector and water source type ⚫Change in groundwater storage ◼Based on contour map for each principal aquifer ◼Graph by water year type ⚫Progress towards implementing the Plan, including achieving interim milestones and implementing PMAs Draft Chronic Lowering of Groundwater Levels 9 ◼Goal: ⚫Adequate spatial distribution, coverage, and well density ⚫Long-term history ⚫Adequate frequency to capture seasonal, short and long-term trends ◼What is needed: ⚫Monitoring History: Available historical data ⚫Well Information: construction information such as well depth and screened interval(s) ⚫Well Access All CASGEM Wells Wells with aquifer specified WCR and depth/screens Depth/screens Only depth Draft Chronic Lowering of Groundwater Levels 10 Aq u i f e r I Aq u i f e r I I Existing Gap Good Spatial Coverage No long history data for RMPs RMPs with good historical records Draft ◼Next steps ⚫Complete missing well construction information ⚫Obtain appropriate access agreements for RMPs and wells that need them ⚫Instrument and drill scheduled wells ⚫Compile data gaps and propose further steps to fill such gaps for coming reviews of the GSP. Chronic Lowering of Groundwater Levels 11 Draft Degradation of Water Quality 12 ◼Goal: ⚫Adequate spatial distribution, coverage, and well density ⚫Long-term history ⚫Adequate frequency to capture seasonal, short and long-term trends ◼What is needed: ⚫Monitoring History: Available historical data ⚫Well Information: construction information such as well depth and screened interval(s) ⚫Well Access ⚫Sampling of COCs with defined frequency ◼COCs ⚫Boron ⚫Iron ⚫Manganese ⚫Nitrate ⚫Specific conductivity ◼Started from all Public/Private Supply wells with DDW Sampling record of COCs. ◼Limited to ones we could identify their aquifers. Draft Degradation of Water Quality 13 ◼Next steps ⚫Coordinate with suppliers to incorporate their wells in the program ⚫Review suppliers monitoring schedule and program to ensure sufficient frequency of COC sampling ⚫Obtain access and sampling agreements if necessary ⚫Obtain and confirm well construction information ⚫Compile data gaps and propose further steps to fill such gaps for coming reviews of the GSP: ◼Aquifer I has gaps in spatial coverage and temporal coverage ◼Possible alternatives not currently included: ⚫GSA monitoring sites: Wells that will be monitored and sampled by the GSA Draft Depletion of Surface Water Monitoring Network 14 ◼Goal: ⚫Characterize spatial and temporal exchanges between SW/GW ⚫Characterize flow conditions: ◼surface water discharge ◼surface water head ◼baseflow contribution ⚫Identify the approximate date and location where ephemeral or intermittent flowing streams and rivers cease to flow ⚫Characterize temporal change in conditions due to variations in stream discharge and regional GW extraction ◼What is needed: ⚫Streamgages and flow measurement ⚫High-frequency GW elevation measurement ⚫Observations of flowing/not flowing conditions ⚫Estimation of depleted volume and changes in condition (integrated model) Draft Reduction in Storage and Subsidence 15 GW Elevation Monitoring Well ◼Subsidence ⚫As discussed previously, InSAR satellite-derived subsidence data product published annually by DWR is proposed to be used for the monitoring. ⚫Benchmark surveys or groundwater levels as proxy can also be used for monitoring subsidence. However, due to lack of historical subsidence in the basin they are not proposed as of now. ◼Reduction in Storage ⚫We propose to use chronic lowering of groundwater levels monitoring network for reduction in storage. ⚫Reduction in storage will be measured using groundwater elevations and will be compared to model estimates. Groundwater elevations will be used as proxy to monitor this criterion. Draft Reduction in Storage and Subsidence 16 GW Elevation Monitoring Well ◼Subsidence ⚫As discussed previously, InSAR satellite-derived subsidence data product published annually by DWR is proposed to be used for the monitoring. ⚫Benchmark surveys or groundwater levels as proxy can also be used for monitoring subsidence. However, due to lack of historical subsidence in the basin they are not proposed as of now. ◼Reduction in Storage ⚫We propose to use chronic lowering of groundwater levels monitoring network for reduction in storage. ⚫Reduction in storage will be measured using groundwater elevations and will be compared to model estimates. Groundwater elevations will be used as proxy to monitor this criterion. Draft Questions? Draft Interconnected Surface Waters and Groundwater Dependent Ecosystems Draft WC §10727.4(l)Impacts to GDEs 19 ◼23 CCR §351(m): “Groundwater dependent ecosystem” ◼Refers to ecological communities or species that depend on: ⚫Groundwater emerging from aquifers; or ⚫Groundwater occurring near the ground surface. Draft Undesirable Results and Minimum Thresholds of GDEs 20 ◼Undesirable Results (UR) for GDEs is the lowering of groundwater levels to cause diminishment of GDE habitat. ◼Minimum Thresholds (MT) for GDE should be historic level of groundwater near the vicinity of mapped GDEs. Management Action Trigger to avoid the MT Leads to Undesirable Result Ideal operating range Draft 1. Mapped Potential GDEs ◼Natural Communities Commonly Associated with Groundwater Dataset (NC dataset) ⚫Collaboration between DWR, CDFW, and The Nature Conservancy (TNC) ⚫Comprised of 2 datasets ◼Vegetation ◼Wetlands ⚫Available via DWR’s “NC Dataset Viewer” ◼DWR 2010 Land Use (Crop Maps 2014 and 2016) ⚫Riparian ⚫Dry stream channel ⚫Water surface 21 Draft 2. Depth to Groundwater 22 Fall 2019 Spring 2019 Fall 2020 Draft Interconnected Surface Waters ◼23 CCR §351(o) “Interconnected surface water” refers to surface water that is hydraulically connected at any point by a continuous saturated zone to the underlying aquifer and the overlying surface water is not completely depleted. Gaining Losing disconnected Losing connected Draft ISW Analysis: Russian River Long Profile 24Red: Russian River Profile Grey/Black: Groundwater Levels Morrison Ck Talmage EF confluence Hwy 20 Draft Next Steps ◼Map connected/disconnected GDEs and ISW ◼Use the model to simulate scenarios and understand impact of groundwater management. ◼Define undesirable results associated with depletion of surface waters that should be avoided. ◼Assess impacts on identified ISWs due to set Sustainable Management Criteria and evaluate whether they avoid undesirable results. ◼Repeat the last two steps while setting SMCs until satisfactory setting is achieved. 25 Draft Questions? Draft GSP’s 3-month Outlook Draft 3 -month Outlook TAC meeting Key topics Key goals GSP chapter production February •Introduction to Interconnected SW and GDE approach •Preliminary discussion on Project and Management actions Receive feedback on data used Interconnected SW and GDEs approach Discussion on PMAs that can be simulated with the GSFLOW model Technical team working already on Chapter 1 and 2, and SMC summary for Water Quality and subsidence for a review by TAC March •Water budget presentation including historical, current and future conditions, and primary scenarios •Comparison of data and model; approach and results for ISW and GDEs analysis Feedback about full water budget Discussion about data and model results for ISW and GDEs Based on TAC feedback, technical team will start drafting Chapter 4 and 5 for PMAs and implementation April •Refinement of Groundwater Dependent Ecosystems (GDEs) and ISW approach •Presentation of possible approach for groundwater level decline SMC •Presentation of possible approach for depletion of surface water Possibly get final feedback about GDEs and how to integrate that into the other SMCs Receive Feedback on groundwater levels SMC Finalizing monitoring networks Technical Team working on finalizing Chapter 2 for water budget and ISW/GDEs Produce relevant SMC subchapters of chapter 3 for TAC review Draft Questions? Ukiah Public SGMA Thank you!