The South American Groundwater Subbasin is North of the Cosumnes River and includes that portion of OHWD that lies between the Cosumnes River and Grantline Road. 

For the Basin, agencies are currently discussing how to manage the basin if a Groundwater Sustainability Plan has to be adopted.  The California Department of Water Resources has not made a determination if the Alternative Plan submitted by the Sacramento Central Groundwater Authority,in 2017 is sufficient for groundwater sustainability.  If it is sufficient, then a Groundwater Sustainability Plan will not need to be adopted for the basin.