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Thursday, July 21, 2016

Lack of Snowfall on Sierra Nevada and Cascades Mountains made our surface reservoirs thirsty but capturing early runoff can be a solution.

                                                                                                    -Harpreet Kaur 

As most of the parts of the world, California too relies on the natural source of water, snow, and rainfall. Snow packs on the Sierra Nevada and Mountain ranges provide 30% of fresh water to the California which melts gradually, releasing water down rivers and into the reservoirs. They refill the streams through the dry summer in this semi-arid region.

2016 snow pack on Sierra Nevada mountains relieved the Californians, thanks to El Nino. El Nino is the phenomenon where trade winds are weaker and pull less warm waters to the Western Pacific, which raises temperatures in eastern pacific and decreases the temperature in western pacific. There is the counter partner of the El Nino known as La Nina, which is opposite of the El Nino. La Nina brings the drier months.

Last year and 2014 was the driest years. The rising temperature in the Sierra Nevada and the Cascades becomes too warms for the snow. Rising temperatures and winter storms becoming infrequent causing more rain and less snow. As a result, the snow didn't refill the summer water supplies. Groundwater and aquifers are shrinking.
This year snow pack saved California getting into deep droughts. But it may not last longer. Global warming is reducing the California’s snow packs by causing it melt earlier in the year and causing heavy rain. “We’re already seeing some of the expected changes to our rain and snowfall patterns; we’re already seeing that we’re getting earlier runoff,” said  Lien-Mager, a spokeswoman for the Association of California Water Agencies.
“That flips our system on its end,” she said. “It was all designed to capture gradual runoff from snow melt. If we’re moving away from that kind of pattern, then we may be getting too much runoff at a certain time, and we won’t necessarily be able to capture it all.”

Dr. Roger C. Bales, a professor at the University of California, Merced said: “Historically, ponderosa pine at the Sierra Nevada has been the reliable show zone, where it accumulates till late March or early April and then melts.” But now the snow pack here is more like that at lower elevations “where it will accumulate, melt accumulate, melt.” Similar Effects of Climate have been seen throughout the Sierra, including at the Central Sierra Snow Laboratory, which is operated by U.C. Berkeley. They make measurements the way the lab started in the 1940s, by inserting special metal tubes into the snow.“We are seeing an ever increasing percentage of the annual and winter precipitation in liquid rather than solid form.” said Randall Osterhuber.

According to Erin Stacey, a scientist with Sierra Nevada research Institute. “The snow pack acts as a reservoir for us, and if we don’t have that reservoir, then we need to find some way to store more water or to use less water.” Measurements done by sensors around the continental United States showed that average snowpack has to decrease as the temperature is rising.

The solution to it is California’s natural aquifers provide a space where that runoff can be stashed until it's needed. Aquifers can be recharged by pumping water into them, or by allowing water to seep into them.“In an ideal world, that large reservoir of water would be available during bad times,” Williams a bio climatology at Columbia University  said. “You could draw down on that when times are really bad, and then when times are really good you can replace it again.”  

Researchers at Stanford have shown that California’s natural aquifers offer cheaper options for boosting water storage capacity than expanding or building above-ground reservoirs. Storing water in aquifers was also shown to be cheaper than desalting and filtering sea water.
But how can we fill the Aquifers? As the city of Fresno is taking an approach in trying to boost their underground supply. When water is present in the reservoirs, it is diverted through small canals to a spreading pond known as leaky acres, where the water seeps down to the aquifers. It is a way to replenish our aquifers. According to the Ken Heard, a chief of the water operations for the city’s public utility department, “Now with the prospect of prolonged or more frequent droughts, we may not be able to do that as much, which means we’ll have to continue using the wells,”

As Heard said this may not help much but it is one of the ways we can preserve the off season melting of the snow and replenish our thirsty aquifers and surface water bodies. These all are the outcomes of the global warming, we should also focus on taking initiatives to reduce global warming.Even small steps like taking transit, riding a bicycle or walking small distances than driving a car not cutting driving completely, planting more trees and lot other small changes in our daily life can make a difference.     

But for bigger steps we should support Carbon fee, which is imposing fees for use of the fossil fuels and shift our company's attention to green energy, using more renewable energy source like solar, the wind, and geothermal energy. Geothermal energy can only be harnessed in places which are active. These are the clean energy and produce less or no waste which is not harmful.   
So collective effort in reducing global warming and capturing runoffs water into the reservoirs and aquifers can solve our problems and relieve the depleting water in major rivers of the country like Colorado river.

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