The Colusa Subbasin Groundwater Sustainability Plan (GSP) was adopted by the Glenn Groundwater Authority on December 14, 2021 and the Colusa Groundwater Authority on December 13, 2021. The GSP can be found on the SGMA Portal

* Please note, the GSP is a large document and may take longer than usual to download.

Annual Reports can also be found on the SGMA Portal or by viewing at the following link:


Prior versions of the draft GSP can be found at the following links:


Other Documents: