Grassland Water District

General Information

The five drainage monitoring sites in the North Grassland Water District capture more than 95% of the wetland drainage to the San Joaquin River. There are occasionally periods when drainage water from Southern Division of Grassland Water District is diverted into Salt Slough through the Blake-Porter Bypass north of Los Banos – however the typical drainage operation is for this water to return to the River through Mud Slough. There is also some groundwater accretion to Mud Slough between the terminal monitoring stations and the San Joaquin River that is not captured by the monitoring network – this is typically less than 5% of the total wetland drainage.