Mount Shasta's Spring Waters, Refugia for Endangered Salmonids

The abundance of cold spring water originating from Mount Shasta in northern California supports productive trout, steelhead and salmon populations in the McCloud, Upper Sacramento and Shasta Rivers. These spring fed rivers are often targeted as refugia areas for endangered salmonids, such as coho salmon and winter-run Chinook salmon, in the face of climate change.   Little is known about source areas of the springs, the age of spring water, and how spring volumes fluctuate within and among years.  California Trout initiated the Mount Shasta spring water study to determine how and if these springs may be impacted due to development (specifically commercial water bottling) and climate change. Water samples were collected from twenty-two springs from 2007 to 2010.  Water samples have been analyzed for a full suite of general water quality and geochemical parameters.  A subset of these samples were also analyzed for oxygen, hydrogen and deuterium isotopes and five of the springs were sampled for Tritium to determine age.  Nine of the springs were monitored for flow to determine if seasonal/yearly fluctuations in flow are occurring.  The isotope data indicates that these springs are all sourced fairly high on Mt. Shasta, at elevations above 5,200 feet, with the majority sourcing well above 6,000 feet.  The age of spring water was variable ranging from several months to over 50 years. This information is being used to develop a vulnerability index for individual springs in response to potential development and climate change.