NEWS

Mt. Shasta Spring Waters: from lore to science

Meadow Barr
Esperanza Spring in the McCloud Watershed, shown, was one of the 22 springs monitored for the “Mt. Shasta Springs 2009 Summary Report.” The information will be used to assist in determining if and how these springs may be impacted due to development and climate change, and to create a vulnerability index for the springs to assist with management decisions.

“The “Big Spring” of the Sacramento is about a mile and a half above Sisson’s, issuing from the base of a drift-covered hill. It is lined with emerald algae and mosses, and shaded with alder, willow, and thorn bushes, which give it a fine setting. Its waters, apparently unaffected by flood or drouth, heat or cold, fall at once into white rapids with a rush and dash, as if glad to escape from the darkness to begin their wild course down the canyon to the plain.” ~ John Muir, in Steep Trails.

There is a fair bit of lore surrounding Mt. Shasta’s spring waters. In his 1891 Pacific Coast Scenic tour describing Big Springs at Mt. Shasta City Park, Henry T. Finck wrote, “[t]hese springs issue from under Mt. Shasta, and doubtless owe their being to the melting of snow and glacier ice by the internal volcanic heat.”

Trails.com claims the water emerging at Hedge Creek Falls in Dunsmuir is 500 years old. Early 20th century Shasta Water ads portray the healing powers of the area’s mineral waters with images of Triton, a god of the sea. The Winnemem Wintu believe that the Mountain’s spring waters keep the volcano cool. While we’ll always have our stories and perceptions about the local springs, the recently released scientific study, “Mt. Shasta Springs 2009 Summary Report” provides some new insight into the age of Mt. Shasta’s waters, and how water travels through Mt. Shasta’s volcanic fissures and comes out as the springs we know and love.

In 2007 local conservation organization California Trout initiated a Mt. Shasta Springs and Groundwater study to assist county and community governments to make science-based policy decisions regarding the water resources of the greater Mt. Shasta area. The 2009 Summary report was prepared for California Trout by AquaTerra Consulting and The Source Group Inc. with assistance from the UC Davis Center for Watershed Sciences. The 33-page report complete with pictures, charts and graphs can be read at www.protectourwaters.org/science.htm.

Scope andpurpose of the study

The scope of the study included taking water samples from 22 springs on Mt. Shasta. Springs at different elevations (high, middle and low) as well as springs located in each of the three watersheds (Shasta, Upper Sacramento and McCloud) were sampled.

The water samples were analyzed for a full suite of general water quality and geochemical parameters. A subset of the samples was also analyzed for oxygen and hydrogen isotopes.  

Five of the spring samples were age dated based on analysis of the tritium isotope. The purpose of the sampling was to determine the elevation that spring water originates on the mountain, as well as if any of the springs may be related.

The flow of nine springs was monitored quarterly to determine if there are seasonal and/or yearly fluctuations.

Together this information will assist in determining if and how these springs may be impacted due to development and climate change, and to create a vulnerability index for the springs to assist with management decisions.

Better understanding the springs will help local municipalities plan for future water supply. In 2010 the study will continue and expand to age date the local municipal water supplies and to start linking precipitation patterns with spring flow.

According to California Trout’s Mt. Shasta Area Manager Curtis Knight, Mt. Shasta’s cold, clean spring waters are an important resource not just for the local economy and water supply, but for the state’s as well.

“We work to protect water for people and fish in California. We are a science-based conservation organization. We initiate research projects like this so we can advocate water management decisions from the standpoint of the best science. This study will build our knowledge base to understand more about Mt. Shasta spring waters to benefit future water management decisions in the area,” Knight explained.

Study History/Background

In 2007 California Trout convened a meeting of scientists to develop the study scope and methodology.  

Dr. Jeffery Mount, director of the UC Davis Center for Watershed Sciences; Carson Jeffres of the UC Davis Center for Watershed Sciences; Dr. Rene Henery, director of the Castle Lake Long Term Laboratory for University of Nevada Reno; Dr. Anthony Saracino, a hydrologist with The Nature Conservancy; and Lisa Unkefer, an environmental engineer with AquaTerra Consulting met and discussed study components such as which springs to study, what characteristics to study, and what equipment and sampling methods to use.

California Trout hired AquaTerra to manage the study, perform the fieldwork, and write the report. After the first year the study was refined and the current report summarizes and analyzes the first two years of data.

Main Findings

Tritium analysis to date age of water and determine residence time

When asked how we determine the age of water, Unkefer explained that prior to above ground nuclear testing there was 3 to 4 kilograms of the tritium isotope on the earth’s surface. In the late 1950s and early ’60s nuclear testing in the high latitudes of the northern hemisphere increased tritium by 2 to 3 orders of magnitude, which enable us to measure concentrations of the isotope in water to determine the age of water less than 50 years old. Water older than 50 years would have to be aged using different methods.

Of the five springs tested for age, Carrick Springs and Mt. Shasta Big Springs were older than 50 years, Muir Springs was 14 years old, and two springs 20 feet apart in the Shasta River Big Springs complex aged at 26 and 44 years respectively.

“The fact that two springs only 20 feet apart had such a difference in age show the complexity of Mt. Shasta’s fractured rock geology and that there are waters flowing in close but separate paths,” Unkefer postulated. She further explained that residence time simply means how long the water is in the ground from when it fell as rain or snow on the mountain until it emerges as spring water.

Geochemical analysis to relate springs

Paul Horton, hydrogeologist and partner in The Source Group, Inc., has performed preliminary data analysis of the geochemical sampling results. Horton is a part time resident of the area and has studied the mountain’s springs for different parties for the better part of 15 years.

When asked what people should know about his findings he said, “They have great water and they’ll always have great water.”

While this is just a preliminary look at the data, Horton hopes to input data from several studies that have been done in the area and to take a holistic look that gets at deeper questions. “On the surface, Shasta’s water is remarkably similar,”?he said. “It is very low in total dissolved solids and relatively young. Mt. Shasta is a relatively young mountain. The water moves relatively quickly through unweathered andesite and thus doesn’t have a lot of time to pick up minerals from the rocks. When I can input more data into the AquaChem analyzing database we’ll be able to find differences that can tell slightly different stories about the water.”

Unkefer said, “As Horton explains in his analysis of the geochemical data, the springs we sampled are very similar with exception of the springs in the Shasta Valley which have more nutrients. We presume that the springs in the Shasta Valley have a longer circulation path or residence time (how long water takes from when it falls on the mountain to when it comes out as spring discharge). The source of these springs is high on the mountain, they have a lower discharge elevation, and they may also come in contact with marine shales, which allows the water to pick up more nutrients on the way.

“Some of the springs emerging in the Shasta Valley are also slightly different in terms of temperature. They are categorized as ‘slightly thermal’ meaning they are 11 degrees Celsius as opposed to less than 10 degrees Celsius. It is postulated that these waters have a deep flow path and potentially come in contact with a geothermal source in the mountain. Again signifying the different flow paths in close proximity, only a 10-minute walk apart, Beaughan Spring is nonthermal while East Boles is slightly thermal,” Unkefer said.