Visiting Sierra Nevada in Fall (1): Source of Our Water

On an October morning, we went to the Sequoia and Kings Canyon National Park.  It was a very clear and nice fall morning.  On high way 99, you could see the irrigation ditch running parallel to the free way.  Though tiny from afar, the blue color of the water contrasted briskly with the yellow banks along it and mountains behind it.  Sierra Nevada and its snowpack, is the source for the water, which we will see very soon.

irrigation

South Fork, Kings River

After we watched in awe the giant Sequioas the first day, we went to the Kings Canyon National Park the next day.  When driving on the road into the park, one could see water running in the canyon to the right of the road, in the yellow and golden fall foliage.  The views were spectacular.

This is the South Fork of the Kings River, one of the three forks that form the river (the other two are Middle and North Fork).

We stopped at Ceder Grove Visitor Center, which  just closed for the winter season.  A short distance away is the river bank of the King river.  The water was so clear, like liquid crystal, moved slowly from east to west.

Kings River 4

Where does all this water come from?  Snowpack in Sierra Nevada, a mountain of which can be seen in the picture above at the back.  However, there was no snow patch visible now.

Every year, during the cold winter season, snows falls on the Sierra Nevada, which means “snowy range” in Spanish.  The whole mountain range captures and stores the vast amount of snow, then at spring time, the snowpack begins to melt and fills rivers with water, like the South Fork of Kings river here.  The snowmelt peaks late spring around March to April, then declines through summer and fall, until it reaches the bottom around September.  So we were at about what was supposed to be the very low point of snowmelt.  The water level should be about the lowest now; usually we might not see all these rocks at the riverbed.

Kings River 5

From here, the water in South Fork flows down Kings Canyon, then join other forks at the foothills of the Sierra Nevada to become the one big Kings River.  Later the Kings River divides into three distributaries, with North Fork Distributary connecting to the Fresno Slough that drains into the San Joaquin River.  San Joaquin River merges with the Sacramento River in Sacramento-San Joaquin Delta (Delta), from which the State Water Project and Central Valley Project deliver the water to many parts of the state, including the Bay area, Central Valley, Los Angles and Los Angeles Basin.  So, when we turn on the tap back in the bay area, the water that comes out may be from the water we see here!

San Joaquin River
By Shannon1 (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 4.0-3.0-2.5-2.0-1.0 (https://creativecommons.org/licenses/by-sa/4.0-3.0-2.5-2.0-1.0)], via Wikimedia Commons
Water Fountain
Water fountain in the Bay area

We continued on.  When we passed the bridge for Roaring River, we decided to go take a small hike.  Roaring river is a tributary for the South Fork;  At the end of the trail, you could see a water fall, tumbling down one after another (the upper one could not be seen in the photo unfortunately).  The water is jade green at the bottom of the fall.  More than 100 years ago, when John Muir saw this water fall, he marveled: “There is one thundering plunge into a dark pool beneath a glorious mass of rainbow spray…”

Roaring River

After the double falls,  the water tumbles down yet another step, then flows to this little pool surrounded by mountains and fall foliage, a stunning beauty in green tranquility.  From here, it merges into the South Fork.

Roaring River

Roaring River 3

We came back to the main road along the South Fork, and went upstream.  Along the way, every view with the river was captivating.

Kings River

Sierra Nevada Snowpack: Critical Source of the Water

All this water comes from snowmelt of the Sierra Nevada, which is so critical for California’s water supply.  As Sierra Nevada Conservancy indicates,  “The Sierra Nevada Region plays a critical role in California’s water supply and hydrological system. More than 60 percent of California’s developed water supply originates in the Sierra Nevada serving end users throughout the State.  Snowpack in the Sierra region provides a natural form of water storage, and Sierra forests and meadows play a role in ensuring water quality and reliability.”

Sierra Nevada Smowpack

By storing the water as snow in winter, and gradually releasing it in warmer seasons, the snowpack in Serra Nevada acts as a gigantic natural reservoir for the state.  According to The Southwest Climate Science Center,  “In California, the spring snowpack on average stores about 70% as much as the water stored in the State’s reservoirs.”

That’s amazing.  The water that flows by in front of us is not just this incredible natural beauty; along with the surrounding mountains, the snowpack there invisible to our eyes, they are part of this huge water storage and delivery system, supporting “more than 25 million Californians and three million acres of agricultural land.”, as indicated by Sierra Nevada Conservancy.  People like us who live in the cities, big and small, depend on it; the state’s agriculture business, at 45 billion in 2016, depend on it.

Challenges for the Snowpack

Such a critical resource, unfortunately, is under some very serious challenges.

The impact from climate change is significant.  According to a study by UCLA Center for Climate Science:

  • “By 2081–2100, if nothing is done to curb greenhouse gas emissions, average temperatures in the Sierra Nevada are projected to increase by about 7–10 degrees F, depending on the month in question, compared with 1981–2000.
  • Warming will be associated with decreases in snow cover in the Sierra Nevada by 2081–2100. For the typical month of April, the land area covered by snow shrinks by 48%, compared with the typical April in 1981–2000. “

In another study published in the peer-review journal Nature in 2017, “Westen U.S. Snowpack could decline 60% by 2040“, with a decline of 30% “very likely”.

  • Reduced snowmelt runoff.  Smaller snowpack means less snowmelt.  This is already happening.  Water Education Foundation indicates that “In the past 100 years, annual runoff that occurs during April to July has decreased by 23 percent for the Sacramento basin and 19 percent for the San Joaquin basin, according to state climate statistics.”  As more than 60 percent of the state’s water supply comes from Sierra Nevada, the reduced runoff is a very serious challenge.
  • Snowline is moving uphill.   Scientists at the Desert Research Institute in a study published in journal Water reported that warmer temperatures have pushed the snow line in the northern Sierra Nevada uphill by 1,200 to 1,500 feet.
  • There will be less snow and more rain.  As the snowline moves up, in the big areas that used to receive snow, now will only receive rainfall.  Snowpack is like a reservoir that releases water gradually throughout the whole year; Rain, on the other hand, will just flow away instantly as runoff.  If we can’t capture and store all the runoff, we will lose a big chunk of water we have today.
  • Runoff timing moves earlier.  For the Sacramento River, compared to 50 years ago, the peak snowmelt time has moved earlier by a whole month, from early April to early March.  Here is the chart showing the changes in peak snowmelt runoff.  When snowmelt peaks early, reservoirs are forced to release water earlier too, which means less water for later when water is needed the most – summer and fall.   If the snow is gone before the reservoirs can recharge, then communities that depend on that stored water will face very tough situations.

Snowmelt Peak

Credit: California Department of Water Resources

  • More wild fires.  Higher temperatures bring more wild fires. The loss of such a big number of trees deteriorates the eco system, reduces the nature’s capacity to store water, further worsening the water supply situation.  As there will be no trees to slow down the runoff, the possibility and hazard of flooding will also greatly increase.
Value Every Drop

On our way home, we crossed the bridge of Kings River.  Looking out of the window, one can see fields after fields of corps, all the way to the horizon.  When one took a glimpse at the water in an irrigation ditch, it was clear, blue, and calm as a mirror, a contrast to the water we just saw in the Kings Canyon.

Kings River

Irrigation Ditch

After it flows out of Kings Canyon, the Kings River comes here and irrigates this vast expanse of land, and beyond.  It has been like that for many years, and it’s natural to think it will continue for many more years.  However, as the Sierra Nevada snowpack will “very likely” reduce by 30% in the next 20 years, the water we see today might not be there tomorrow.

A city completely without water is not just a remote possibility any more, it is happening.  Cape Town, the second largest city in South Africa,  is projected to run into “Day Zero“, when running water will be completely cuts off from the city, in May.

As the natural water supply will only decrease, every drop of the water should be valued.  By improving water use efficiency, Pacific Institute’s indicated in a report that we can save 1 million acre water a year.  Out of all the methods to come up with more water, “improving the efficiency of our water use is the cheapest, easiest, fastest, and least destructive way to meet California’s current and future water supply needs.”

In California, outdoor landscaping watering accounts for half of total urban water use .  To replace water-thirsty lawns with water efficient gardens is one of the most effective ways we can save water.  Building such a garden will not only conserve water, but also beautify our space, provide food to the pollinator, and nurture a healthy eco system.

By putting every drop into the best use,  not only will we have the water we need, we can also best show our gratitude to the nature, and its generous gifts for us for so many years.

 

 

 

 

 

 

 

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