Water Depletion in the Central Valley Due to Agriculture by Denzel Fisher and Osvaldo Hidalgo

       1.      Location

California is the largest agricultural producing state in the United States. Within it, lies the “breadbasket of the nation,” the Central Valley. This temperate grassland, with flat, nutrient-rich soil as well as hot sunny summers, and wet winters is and has become a great place to grow a wide variety of fruits, vegetables, and grains. Agriculture has turned this once thriving desert/grassland, which was full of many different type of grass and animal species (like the Kit Fox, Elk, and Kangaroo Rat) into extremely successful farmland (WWF). This success however, has come at a great cost to the ecosystems of the Central Valley.

The Central Valley is 40 to 60 miles wide and 450 miles long. Located in the center of California, it stretches from Bakersfield to Redding. Consisting of the San Joaquin Valley, the Sacramento Valley, and the Sacramento-San Joaquin Delta, the Central Valley produces 25 percent of the nation’s table food using only 1 percent of its farmland (Bitman 2012). The Central Valley is so successful because farmers have many resources at their disposal, however over-usage of these resources is turning its resource blessing into a scarcity curse. The Central Valley’s groundwater is the second most pumped aquifer in the nation (Famiglietti 2011). Groundwater levels are depleting at a rapid rate leading to groundwater salinization, ground subsidence, and political as well as physical arguments about water availability. If left unchecked, groundwater depletion could lead to Nation-wide disasters, because of the United States’ dependence on Central Valley agriculture.

2.      Specifics of the Problem

The Central Valley’s agricultural tradition began in the mid-nineteenth century, when frustrated

gold miners, stopped searching for their fortune panning for gold, and found it through cultivating the nutrient-rich land with wheat and grains. From the 1850s to the 1890s, these Central Valley farmers abused the land through overproduction, and monocrop grain farming without taking care of the soil, which caused wheat quality to decline. This led to a need to find different crops. Fruit farming was found to be more effective. Technological advances allowed for the introduction and rapid expansion of fruit, vegetables, cotton, hay, and rice, as well as so many other industries like chicken farms, sheep farms, and dairies into the Central Valley. As more varieties of agriculture and different industries were arising, so did the need for irrigation. Many new groundwater pumps, plants, and wells were made in 1950 (Olmstead). These new pumps, plants, and wells were and continue to

be operated by irrigation districts, public corporations run by landowners, who have irresponsibly overused groundwater, for the prosperity of their business, without taking into account the ecological toll the depletion of groundwater would have. Based on studies by the U.S. Geological Survey, scientists have noticed a trend of descending levels of groundwater, with little to no changes with regards to it being a relatively wet or dry year, regarding rain. Naturally, the Central Valley’s groundwater is recharged by runoff from the Sierra Nevadas, however, due to climate change, it has been snowing less in the Sierra Nevadas. Lack of snow however is only part of the issue. The groundwater under any specific area takes a considerable amount of time to replenish, so taking more out than you are putting in after many years can cause serious problems. Agriculture uses 60 percent of the available freshwater in the United States. Overuse of groundwater has led to land subsidence of up to 28 ft. in some parts of the Central Valley. Consequences of land subsidence could include above-ground flooding, and decreased aquifer storage in these areas, and has an estimated cost of $25,000,000. It has also started a “water war” between the Sacramento/San Joaquin Delta area and the Central Valley, over the San Joaquin River Delta’s water. If the Central Valley does not find a way to effectively regulate it’s usage of groundwater, they will only see the current situation worsen.                                

  3.     Larger Consequences of the Problem

      Water depletion is taking a toll on the Central Valley, however if it continues, even larger consequences could occur. If left unchecked, groundwater depletion could lead to soil salinization,

“water wars,” and national agricultural disaster due to groundwater depletion. Years of poor maintenance and over-use have led to the damaging of the soil. Salt from the San Joaquin River and the Tulare Lake Basin have led to surface water salinity. When groundwater in the surrounding areas are used up, the ground takes in the salty water from these sources leading to the damaging of the soil. Not only is the soil being damaged, but water sources are running out. Governor Jerry Brown has declared California to be in a drought state of emergency. As aquifer water supplies are being depleted, some farmers call for water extractions from more abundant sources like the San Joaquin River Delta, causing the infamous “California Water

Wars.” The lack of water has turned Central Valley farmers against the fishing industry on the San Joaquin River Delta. California government has had to choose between losing crops, or allowing people and other species that rely on the San Joaquin River Delta to suffer. A big controversy has arisen over the Delta Smelt, a non-native fish species that, in the event water was taken from the San Joaquin River Delta, could go extinct. Farmers believe this is a small price to pay to save the ability for them to continue growing as much food as they do now. The biggest risk that can come from water depletion, is complete water depletion. Groundwater takes years to accumulate, so once it’s all gone, it is very hard to recover. Satellite imagery measuring water storage from October 2003 to March 2010 have shown that groundwater storage has been shrinking and not being restored at a normal rate, as displayed by table below (Famiglietti 2011).

Trends and volumes are for October, 2003–March, 2010 unless otherwise noted.	Trend (mm yr−1)	Volume Lost (km3)
Total Water Storage	−31.0 ± 2.7	30.9 ± 2.6
Snow Water Equivalent	−1.6 ± 0.4	1.5 ± 0.3
Surface Water Storage	−8.8 ± 0.2	8.7 ± 0.1
Soil Moisture	−0.2 ± 2.8	0.1 ± 2.7
Groundwater Storage	−20.4 ± 3.9	20.3 ± 3.8
Groundwater Storage (2003/10–2006/03)	−1.4 ± 12.7	0.5 ± 4.8
Groundwater Storage (2006/04–2010/03)	−38.9 ± 9.5	23.9 ± 5.8
Table 1. Trends in Water Storage for the Combined Sacramento-San Joaquin River Basinsa

Not only will this further sink subsidized areas, but it could cause great harm to the agricultural industry. As we mentioned earlier, the United States relies heavily on the Central Valley for its diverse abundance of crops.

4.      Solutions

Image Credit Water FX

Everybody seems to have different ideas about how to solve the drought problem in the Central Valley and in all California. The ideas/methods we found to be more likely to be attempted are California politicians and farmers pressuring Congress in order revert water usage from groundwater to other sources, like from less-used surface water in the Central Valley, water from the mid-west, or from solar-powered desalinization plants. Farmers have pushed for bills like “The San Joaquin Valley Water Reliability Act (H.R. 1837)” that would pump water from the San Joaquin River Delta for crop use. This bill has been strongly opposed by many, including U.S. Senators Dianne Feinstein and Barbara Boxer, as well as President Barack Obama. This bill’s passing would serve only slow down water depletion, not end it, and would cause great harm to the San Joaquin River Delta, or from whatever surface water source they take it form, and the species that live in and rely on it/them. A way to get water for crops without damaging the Central Valley as much, is the use of

solar-powered desalinization plants. Using solar power to purify water is much more efficient, environmentally effective, and cost effective than using fossil fuel-centered methods. Solar-powered methods release larger amounts of usable water, and less salty brine. Methods like WaterFX (93%) have high recovery rates, however that does not solve the salty brine issue, and still only helps lessen the severity of the situation, but it does not solve the issue of groundwater depletion. The idea we thought to be most effective is a switch to sustainable farming. Farmer Paul Buxman from Dinuba, California encourages a push to more conventional methods that would lead to sustainable farming. With systems such as “California Clean” farms would have to be no larger than 100 acres, would have to have a single family as its primary laborers, would require the food to be of high quality with high nutrition, and would require the farms to have an active biology, meaning healthy soil, birds, worms, etc. (Bittman 2012). Such methods are expensive and not accessible by everybody, however farmers like Buxman believe they can make a great change simply by encouraging farmers to use less and more precise pesticides to reduce the poisoning of the groundwater the Central Valley has left, and reduce tillage and water use.

       5.      Conclusion

At the rate in which groundwater is being used in the Central Valley, the future does not look good. No one knows exactly how much groundwater the Central Valley has left, but estimates have optimistically stated that it would dry out by 2050. The effect this could have on the nation is terrible to think about however, we believe that the future of groundwater in the Central Valley can be changed. The Central Valley’s water issues, like that of most highly developed countries, will never be solved unless the people who reside there learn moderation. It will take a long time, but if everybody gets on the same page and actually makes an effort to conserve water, we could potentially stop water depletion, poisoning, salinization, and land subsidence. Through enough years of practicing moderation, we could reach a point where the groundwater in the Central Valley will start to become replenished at a constant rate, naturally by snowmelt from the Sierra Nevada. If we let nature take care of itself, instead of continuing to allow humans to abuse nature, we will all find ourselves in a better situation, and ecological issues such as groundwater depletion in the Central Valley will become less prevalent.

Bibliography

Bittman, Mark. "Everyone Eats There." The New York Times. The New York Times, 13 Oct. 2012. Web. 04 Mar. 2015.

Famiglietti, J., Lo, M., Ho. S., Bethune, J., Anderson, K., Syed, T.; Satellites Measure Recent Rates of Groundwater Depletion in California’s Central Valley; Geophysical Research Letters, Vol. 38, L03403; 5 Feb. 2011

Galloway, D. “San Joaquin Valley, California” United States Geological Survey (USGS); Circular 1182, 1992

Maven. “Delta Smelt: Scapegoat for Water Problems.” Digital Image. Maven’s Notebook. 26 Feb. 2013.

            Morris, Bob. Save the Delta Poster. Digital image. Politics in the Zeros. WordPress, 11 Jan. 2014. Web. 5 Mar. 2014.

Olmstead, Alan L., and Paul W. Rhode. “The Evolution of California Agriculture 1850-2000” (n.d.): n. pag. Web.

Olsen, David, and Robin Cox. "California Central Valley Grasslands." WorldWildlife.org. World Wildlife Fund, n.d. Web. 04 Mar. 2015.

Ortiz, Edward. "Valley Groundwater Threatened If Farm Use Continues at Current Levels | Earth System Science." Valley Groundwater Threatened If Farm Use Continues at Current Levels | Earth System Science. Department of Earth and Science: University of California Irvine, 22 July 2012. Web. 05 Mar. 2015.

Regional Charectersitics. Digital image. Http://ca.water.usgs.gov/projects/central-valley/about-central-valley.html. 26 Feb. 2013. Web.

Sokolow, A. Lemp, C; California Agriculture 56(1):9-14. DOI: 10.3733/ca.v056n01p9. January-February 2002. (Peer Reviewed Journal)

Spector, Dina. "An Unconventional Desalination Technology Could Solve California's Water Shortage." Business Insider. Business Insider, Inc, 12 Mar. 2014. Web. 05 Mar. 2015.

US Geological Survey. Groundwater Graph. Digital image. Groundwater Graph. Sacramento Bee, 22 July 2012. Web. 04 Mar. 2015.

World Wildlife Fund: Olsen, David, and Robin Cox. "California Central Valley Grasslands." WorldWildlife.org. World Wildlife Fund, n.d. Web. 04 Mar. 2015.