TO: Technical Advisory Group for the Napa County Groundwater Sustainability Agency
FROM: Brian D. Bordona, Director of Planning, Building and Environmental Services
REPORT BY: Jamison Crosby, Natural Resources Conservation Manager
SUBJECT: Update on the Interconnected Surface Water (ISW) Groundwater Dependent Ecosystems (GDEs) Workplan implementation and on the California Environmental Flows Framework (CEFF) assessment
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RECOMMENDATION
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Receive an update on the Interconnected Surface Water (ISW) Groundwater Dependent Ecosystems (GDEs) Workplan implementation and the California Environmental Flows Framework (CEFF) assessment.
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Procedure
Staff introduces.
Questions and answers with the TAG.
Public comments.
BACKGROUND AND DISCUSSION
A fundamental knowledge gap in setting sustainable management criteria in the Napa Valley Groundwater Subbasin (Subbasin) is understanding the spatial and temporal flow requirements of sensitive species. To fill this knowledge gap, the Napa County Groundwater Sustainability Agency implemented the Interconnected Surface Water (ISW) and Groundwater Dependent Ecosystems (GDEs) Workplan (Workplan) starting in 2024. The Workplan includes field investigation of the timing and usage of the Subbasin by special status fish, amphibians, and reptiles at six sites including four sites on the mainstem Napa River (Calistoga, St. Helena, Yountville, and Oak Knoll) and two tributaries (Sulphur Creek and Bale Slough). California freshwater shrimp (Syncaris pacifica) surveys were limited to the Napa River at Calistoga, which is within the critical habitat area for the species. Biological surveys also included riparian GDEs including vegetation and birds. In addition to biological surveys, the Workplan also called for monitoring of shallow groundwater, surface water stage, wet-dry mapping, water temperature, and dissolved oxygen.
Following the Groundwater Sustainability Plan for the Subbasin, the Workplan recommended using the California Envi...
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