Guidance for Climate Change Data Use During Groundwater Sustainability Plan Development

This Guidance Document was developed to help Groundwater Sustainability Agencies (GSAs) incorporate California Department of Water Resources (DWR)-provided climate change and related data into their Groundwater Sustainability Plans (GSPs). The purpose of this Guidance Document is as follows:

• Provide relevant data and tools for GSAs to incorporate climate change into their GSPs.

• Provide an analysis approach using the provided data and tools that incorporates the best available science and best available information to date.

This Guidance Document focuses on the use of DWR-provided climate change data and provides documentation about the following:

• Climate change data development approach

• Climate change data development methods and processes • Applications for using the provided climate change data

• Climate change data assumptions and limitations

This Guidance Document provides a process for using DWR-provided climate change data for computing projected water budgets and serves as a companion document to the water budget best management practices (BMPs)2 and the modeling BMP3. For Sustainable Groundwater Management Act (SGMA) implementation purposes, the use of climate change data can help with the following:

• Developing projected water budgets

• Long-term planning of groundwater basin sustainability

• Assessing projects and management actions by performing sensitivity analyses of projected conditions

• Adaptive Management