You’re Invited! March 19, 2026
2025 Annual Water Report – Draft
This Water Year (WY) 2025 Annual Report for the Basin has been prepared in compliance with CCR 23 §
356.2 and consistent with the DWR’s October 2025 GSP Implementation: A guide to Annual Reports,
Periodic Evaluations, & Plan Amendments. WY 2025 includes the period from 1 October 2024 through 30 September 2025. This Annual Report also contains available and appropriate historical information back to 2015, as required by CCR 23 §356.2 (b).
The Basin encompasses 210,300 acres at the northern end of the San Joaquin Valley Groundwater Basin
within Sacramento and Amador Counties. It is bordered on the north by the South American Subbasin (DWR Basin No. 5-021.65) and on the south by the Eastern San Joaquin Subbasin (DWR Basin No. 5-022.01). The Basin is bounded by surface water features to the north, south, and west and the eastern Basin boundary is formed by low permeability metamorphic rocks in the Sierra Nevada
foothills region. The Basin has a single Principal Aquifer which is comprised of six hydraulically connected
sedimentary formations that include the Younger Alluvium, Victor, Laguna, Mehrten, Valley Springs, and
Ione Formations.
Read the Draft Annual Report for Water Year 2025 to find out more.
“Alone, we can do so little. Together, we can do so much” – Helen Keller (on the importance of community)
Cosumnes River Preserve