Contra Costa County, California monitoring locations

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• Scheduled Maintenance Notice
  USGS will be performing maintenance on the time series data processing system beginning at 09:00 EDT on September 10, 2026. During this period, delivery of the latest time series data will be delayed. The maintenance is expected to finish within 2 hours, after which all backlogged time series data will be processed and delivered to WDFN web portals and APIs.