Is the Diminishing Sierra Nevada Snow Pack Jeopardizing our Water?

By Julian Brastow

Today, our society faces an ongoing problem that threatens the earth’s future and continues to manifest itself in our everyday lives. This problem, global climate change, has been evident for decades, and has been causing all kinds of global disasters, from severe weather and inland flooding, to receding polar ice sheets and rising sea levels. A more local problem, however, that threatens California’s water supply, is the diminishing Sierra Nevada snowpack.

The winter snowpack of the Sierra Nevada and Southern Cascade mountains is extremely important to the water systems of California. Snow builds up in the Sierra Nevada and lower Cascades in the winter, acting as an enormous, natural reservoir, and then slowly melts into streams and rivers during the spring months, filling up the surface reservoirs all over California. These reservoirs provide water to much of California, including large cities like San Francisco and some of Los Angeles and San Diego. In addition, 50% of the water flow into the Sacramento-San Joaquin Delta, the hub of California’s water system, comes from the Sierra.

California has now been in a drought for almost five years, and although the 2016 snowpack was considerably better than the previous couple years, it has in no way pulled us out of the drought, and was still below average. In addition, the 2015 snowpack was the lowest ever recorded, at five percent of average. Using tree ring evidence, scientists estimated that it may have been the lowest in five hundred years. That won’t happen again, right? In fact, years like the last are expected to occur again in subsequent decades. Even twice in one decade, thanks to global climate change.

Interactive Snowpack Map

There are two ways the state of California can try and solve this problem. We can either look to alternative water sources and somewhat ignore that our average snowpack is diminishing, or we can look to why this is happening and try to combat climate change. The first option would only be successful if vast alternative water sources were available in the long run. But the more reliable option, and the one that would last relatively forever, would be to look to the overhanging source of this long term problem, and try to restore the damage we have already caused.

Map of California's Aquifers

An alternative water source to the Sierra Nevada snowpack is the large aquifer (water table) beneath the Central Valley. An aquifer is a body of permeable rock that can contain or transmit groundwater, and also acts as a large, natural reservoir. Many farmers in the Central Valley already use the aquifer as a water source in the form of pumping groundwater to the surface. The problem with using the aquifer as an alternative water source, however, is that it replenishes itself naturally very slowly, and if we take water from it regularly, it must be manually replenished on years that we have an excess amount of water. One of its main sources is also the Sierra Nevada mountains, so it would be very unsustainable to use as an alternative.

Another alternative water source would be to increase the amount of desalination along the state’s coast. While this may seem like an obvious idea, desalination is extremely expensive and can also cause harm to the surrounding environment if we are careless about the source of intake and what we do with the wastewater. We will need to look to more sustainable water resources if we want to succeed in the long run.

By far the most sustainable alternative water source would be recycling wastewater. This option fundamentally just makes the most sense, because there is all this wastewater from your sink, shower, etc. going down the drain and not being used again. So why not use it to water your garden or flush your toilet? Water recycling and greywater (on-site reuse) has the ability to meet the needs of non-potable water demands not just in your house but also in the agricultural industry. If we took full advantage of greywater and water recycling, then the need for new water would be lowered vastly.

In the end, we need to look at global climate change as the leading factor of the diminishing snowpack. If we don’t accept this problem, and act, then our water sources will continue to decrease. It’s easier said than done, but there are multiple ways, large or small, to combat climate change. Since pollution from fossil fuels is the source of climate change, it is important to reduce your emissions as much as possible. On a larger scale, we need to move away from nonrenewable energy like natural gas and coal. 63% of California’s electricity comes from natural gas, and although this is a much better option than coal, it still pollutes the atmosphere and it would be better in the long run to focus more on renewable energy sources. If we succeed in this, California will be able to continue to protect its most important resource, water, for many generations to come.