Water in the Western United States - California: A Case Study
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California, the largest water user in the US, has seen a decline in total water use since the 1980s, with significant withdrawals for irrigation and thermoelectric power generation. Recent drought conditions have led to a state of emergency and record low snowpack levels, severely impacting water supply. Solutions proposed include stricter conservation measures, improved irrigation practices, and potential amendments to outdated water rights laws.
Water in the Western United States - California: A Case Study
- 1. Water In The Western United States California – A Case Study Jonathan D’Cruz
- 2. Introduction • California uses more water than any other state in the US • Each Californian uses an average of 181 gallons of water each day against the national average of 80-100 gallons each day • More water is used each day for irrigation than any other category • Total water use has been declining since the 1980s • California has been the state with the largest water use in the US since the USGS began compiling water-use data in 1950 Source: USGS
- 3. Facts & Figures Source: USGS
- 4. Facts & Figures Source: USGS
- 5. Facts & Figures Source: USGS
- 6. Facts & Figures Source: USGS
- 7. Total Withdrawals • In 2010, Californians withdrew an estimated total of 38 billion gallons of water per day, compared with 46 billion gallons per day in 2005. • Surface water withdrawals in California were 25 billion gallons per day (67%), compared with 35 billion gallons per day (76%) in 2005. • Groundwater withdrawals accounted for 13 billion gallons per day (33%), compared with 11 billion gallons per day (24%) in 2005. • About 82% of all California water withdrawals were from fresh-water sources, compared with 72% in 2005. – In both 2005 and 2010, about 74% of all fresh water withdrawals were for irrigation. – 95% of all saline water withdrawals were for thermoelectric power generation, compared with 98% in 2005. Source: USGS
- 8. Withdrawals by Category • 38 billion gallons of water withdrawals per day were distributed among 8 categories: • Irrigation: 60.7% (23,056 million gallons per day) • Thermoelectric power generation: 17.4% (6,601 million gallons per day) • Public supply: 16.6% (6,307 million gallons per day). Average daily gross per capita use was 181 gallons (total Public Supply withdrawals divided by population served). • Aquaculture: 2.6% (973 million gallons per day) • Industrial: 1.0% (400 million gallons per day) • Mining: 0.7% (272 million gallons per day) • Livestock: 0.5% (188 million gallons per day) • Self-supply domestic: 0.5% (172 million gallons per day). Average daily per capita use was 69 gallons. Source: USGS
- 9. California Drought & It’s Impacts • On January 17, 2014 California State Governor, Jerry Brown, declared a drought state of emergency and cut water use by 20% • California’s water demands are mainly met by a snow melt hydrology • On April 1, 2015, the California Department of Water Resources measured the statewide water content of Sierra snowpack at five percent of average for April 1st. • These levels are lower than any year in records going back to 1950. • The April 1 snowpack measurement is crucial because this is when the snowpack is normally at its peak and begins to melt into streams and reservoirs. Snowpack, through runoff, provides about one-third of the water used by California's cities and farms. • California's 2014 Water Year, which ended September 30, 2014, was the third driest in 119 years of record. It also was the warmest year on record. Source: USGS
- 10. California Drought (Shasta Lake Reservoir) Source: USGS
- 11. California Drought (Shasta Lake Reservoir) • These two Landsat images show the changing shoreline of Shasta Lake reservoir in northern California over the past three years. • The first image was collected in September 2011 and shows the shoreline when the reservoir's water levels were at 77 percent of total capacity. • The tan colors in the September 2014 image show the change in shoreline. Even though snowmelt slightly increased the lake level earlier in 2014, the reservoir was still at only 27 percent capacity when this more recent image was acquired. • The lower right portion of the second image also shows a recent burn scar from the Gulch Fire. This fire was officially contained one day before the September 17 image was collected. Source: USGS
- 12. California Drought (Shasta Lake Reservoir) Source: USGS
- 13. California Drought (Shasta Lake Reservoir) • Located in Shasta County, Shasta Lake is the largest manmade reservoir in California, with a capacity of 4,552,000 acre-feet. • These photos, taken in February, 2014 and October, 2014, illustrate the declining water levels in the reservoir. • Shasta Lake provides abundant recreation, including boating, fishing, swimming, water skiing, camping, hunting, and house boating. • Releases from the reservoir serve to control floodwaters and store surplus winter runoff for irrigation in the Sacramento and San Joaquin Valleys, maintain navigation flows, provide flows for the conservation of fish in the Sacramento River and water for municipal and industrial use, protect the Sacramento-San Joaquin Delta from intrusion of saline ocean water, and generate hydroelectric power. Source: USGS
- 15. California Drought • These three images show a portion of California's Central Valley (left side of the images) and the neighboring Sierra Nevada mountains as viewed by Landsat in February 2011, 2013, and 2014. • The reduced winter snowpack in the Sierra Nevada mountain range is concerning, as snowpack, through runoff, provides about one-third of the water used by California's cities and farms. • The decrease of winter snow cover can be seen in this progression of images. The reduction of available water supplies in the Central Valley is also indicated by the changing outlines of Folsom Lake, Camanche Reservoir, and other lakes and reservoirs in the images. Source: USGS
- 16. California Drought Source: US Drought Monitor
- 17. California Drought Problems • Agriculture accounts for 60% of water consumption in California. Farmers flood the land to grow rice, alfalfa and other thirsty crops. • By one account, over the years farmers have paid just 15% of the capital costs of the federal system that delivers much of their irrigation water. • Snowpack in the Sierras fell to 12% of average January levels. • Rainfall has disappointed for three years. • Due to declining flows of the Colorado river, last year the Federal Bureau of Reclamation (FBR), which oversees its use, cut the release of water from Lake Powell on the Arizona-Utah border to Lake Mead, America’s largest reservoir. It has never done this before. Source: The Economist
- 18. California Drought Problems • The law of the river, which allocates precise amounts of water to the seven Colorado-basin states, was signed in 1922. The region has grown quickly and unevenly since then but the law has proved resilient; states used to sue each other with wearying frequency but now work together well. • The problem is that 1922 fell in an unusually wet period. • For decades that did not matter; the basin states were not big enough to demand their full allocation. No more: five of the seven states sharing it’s waters are among America’s ten fastest- growing states. • Moreover, climate change may be reducing supply even as demand rises. In 2012 the FBR said that by 2060 the supply gap from the Colorado could reach 3.2m acre-feet Source: The Economist
- 19. Northern California’s Folsom Lake on January 16, 2014 Source: NBC News
- 20. California Drought Problems • Traditionally the West has tried to engineer its way out of water problems, and that approach is not dead in Nevada. • Greater Las Vegas, where most Nevadans live, depends on Lake Mead for 90% of its water, but before long the lake is expected to fall below the level of the first of two pipes that connect it to the city. • So officials are building a deeper $816m “third straw” to maintain supply. They also want to lay a 300-mile pipeline to bring water from Nevada’s sparsely populated north to Las Vegas, a controversial plan some compare to Los Angeles’s removal of water from the Owens Valley 100 years ago. Source: The Economist
- 21. California Drought Problems • Unhappily for Nevada and Arizona, California’s problems are also theirs. Southern California is entitled to 4.4m acre-feet of Colorado water a year, mainly for farmland in the Imperial Valley. • Under a 2007 agreement the three states may store water they do not need in Lake Mead for later withdrawal. Because of its drought California is now drawing down the 580,000 acre-feet it has saved in recent years; it took around 80,000 in 2013. • That is hastening the day when Mead falls below 1,075 feet (it is currently at 1,109) and compulsory cuts kick in. • For complex historical reasons Nevada and Arizona will lose a combined 500,000 acre-feet a year before California has to give up a drop. Source: The Economist
- 22. U.S Drought Monitor April 28th, 2015 Source: US Drought Monitor
- 23. California Drought Problems • Criticism of the state water rights system was spurred last year with the release of a UC Davis study that found the state’s water rights collectively amount to five times as much water as runs off the state in an average year, leading many to conclude the state has overpromised the increasingly limited resource. Source: UTSanDiego
- 24. California Drought Problems Source: UC Davis & UC Merced
- 25. California Drought Solutions • Strict enforcement of water shortage contingency plans • Judicious use of groundwater sources to meet requirements • Farmers to trade water hungry crops for drought resistant crops • Use of micro-sprinkling and drip irrigation, and doing laser leveling of fields to reduce runoff • Installation of water meters wherever needed and possible to regulate water use • Investing in public outreach campaigns to educate water users regarding new restrictions and judicious use of water • Incentives for replacing lawns with drought-resistant or native plants. Source: National Geographic
- 26. California Drought Solutions • Policy to encourage conservation by pricing water in tiers, depending on water usage • Moratorium on issuing new water service permits, a ban on draining and refilling pools, and strict limits on outdoor watering, with penalties imposed for violations • Buying water from farmers north of the Sacramento Delta, who would fallow their fields and profit from the sale of their water rather than their crop • Possibly revisiting California's riparian water right laws (framed in the 19th century) and make suitable amendments to suit the 21st century needs Source: National Geographic