GSA update outlines regional coordination on interconnected surface waters

Wyandotte Creek GSA staff reported on interbasin coordination among neighboring subbasins in the North Sacramento River Corridor, outlining a five-pillar framework intended to support ongoing GSP implementation and future periodic updates.

Dylan (program manager) described five collaborative pillars: information sharing; joint analysis and evaluation; coordination on mutually beneficial activities; coordinated communication and outreach; and issue resolution. He said a joint analysis completed in 2025 by Butte County on behalf of Wyandotte Creek and Vina GSAs identified data differences, uncertainties and potential impacts related to groundwater–surface-water interaction.

Dylan said interconnected surface waters (ISWs) rose to the top of regional priorities following DWR corrective actions and that regional data collection, refined modeling in coordination with DWR, and a regional guidance document could produce compatible tools and reduce costs. "Just because one subbasin goes with one thing does not mean that they're making a decision for all of the subbasins," Dylan said, emphasizing that local authority over policy decisions remains with each GSA.

Cammie Loeser, Butte County director of water and resource conservation, added that the Wyandotte Creek GSP uses a similar framework to other corridor GSAs and noted county materials and webinars on the topic are available on the Butte County website. She said the county has also sent a letter to the Department of Water Resources (DWR) requesting regional modeling to support ISW evaluations.

The update was informational; the board did not take formal action on regional coordination at this meeting.