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This is a brief explanation of the Cosumnes River diversion into our storage reservoirs (Calero, Chesbro, Clementia) for the Water Plants to process into drinking water for community use.

Depending on flow levels in the river, water may be pumped from the Granlees pump station to Calero or Chesbro, through a 33” pipeline, or to Clementia through a 21” pipeline. Typically we will fill Calero first.

Diversion from the Cosumnes River may start November 1st and end by May 31st. Typically river flow from the first storms is allowed to pass by, flushing out the river system of sediment and possible contaminants washed in from roadways and agricultural areas, as our goal is to pump the cleanest water possible while being able to fill our reservoirs to maximum capacity each year.

For more detail go to our website here:

View Cosumnes River flows at the Michigan Bar gauging station on the web here: