I have been monitoring the drought in the Southwestern U.S. for a decade with an emphasis on the drought impacts in The Las Vegas area and Lake Mead.
Note the following links for the previous reports that I have created for the High Plains Regional Climate Center, The National Drought Mitigation Center and the Applied Climate Science Group here in the School of Natural Resources at UNL.
Year 2009 Drought in the Southwestern U.S.
Year 2007 Drought in the Southwestern U.S.
Year 2006 Drought in the Southwestern U.S.
Year 2003 Drought in the Southwestern U.S.
Year 2002 Drought in the Southwestern U.S.
Year 2012 Lake Mead Update (December 2012):
Lake Mead is the largest reservoir in the U.S. It is located on the Colorado River about 25 miles from downtown Las Vegas and located at the Nevada/Arizona border. It is formed by the Hoover Dam, and when full, Lake Mead is 112 miles long, has a maximum depth of around 500 feet and it also has 550 miles of shoreline. Lake Mead has not reached capacity for more than a decade and has been lowered due to two factors: (1) increased human demand for water in the Las Vegas Valley and (2) by a prolonged drought in the Southwestern U.S.
Lake Mead Elevations:
Lake Mead Maximum Elevation (Capacity): 1229.0 feet
Lake Mead Elevation, December 2012: 1120.36 feet (108.64 feet below capacity, 95.40 feet below the 1998 peak elevation)
Lake Mead elevation, most recent peak, October 1998: 1215.76 feet (13.24 feet below capacity)
Lake Mead elevation, record minimum, November 2010, 1081.94 feet (146.64 feet below capacity)
Historical Lake Mead Elevations are listed below in a table for the time period 1935-2012.
Lake Mead Facts: (Information source, Bureau of Reclamation, Lower Colorado Region, Boulder City, NV)
What is the lake's elevation at high-water?
The high-water line is at 1,229 feet above sea level. At this elevation, the water would be more than 7 1/2 feet over the top of the raised spillway gates, which are at elevation 1,221.4 feet. All lands below elevation 1,250 have been retained for reservoir operations purposes.
What is the reservoir's area?
At elevation 1,221.4 feet the reservoir covers about 158,500 acres or 248 square miles.
How long and wide is the reservoir?
At elevation 1,221.4, Lake Mead extends approximately 110 miles upstream toward the Grand Canyon. It also extends about 35 miles up the Virgin River. The width varies from several hundred feet in the canyons to a maximum of eight miles.
How much water will Lake Mead hold?
Approximately 28,945,000 acre-feet. An acre-foot is the amount of water required to cover one acre to a depth of one foot, or approximately 326,000 gallons. The reservoir will store the entire average flow of the Colorado River for two years. That is enough water to cover the State of Pennsylvania to a depth of one foot.
How is the reservoir capacity allotted?
Below elevation 1,229, about 1,500,000 acre-feet of storage capacity is reserved exclusively for flood control; about 2,547,000 acre-feet for sedimentation control; about 18,438,000 acre-feet for joint use (flood control, municipal and industrial water supply, irrigation and power); and 7,683,000 acre-feet for inactive storage.
Who operates the dam and reservoir?
The Bureau of Reclamation operates and maintains the dam, power plant and reservoir. The National Park Service administers recreational activities in and around Lake Mead as part of Lake Mead National Recreation Area.
What is the estimated annual evaporation of the reservoir?
About 800,000 acre-feet each year.
Where does the water from Lake Mead go for household use?
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Irrigation: 47%
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Water Waste: 23%
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Toilet: 8%
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Laundry: 6%
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Other Indoor Use: 6%
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Faucet: 5%
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Shower: 5%
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Source, City of Henderson, Las Vegas and North Las Vegas.
Graphing the Changes in Elevation of Lake Mead:
The following graph shows the elevation of Lake Mead for each December 1935 through 2012.
The month of December was chosen to correspond to my most recent visit to Lake Mead in December 2012.
> The level of Lake Mead at Hoover Dam started falling in November 1998, just after it reached the
all-time high of 1215.76 feet.
> Lake Mead reached its lowest point at 1082.36 feet in October 2010, 133.4 feet below the peak of 1998.
> Lake Mead was dedicated in 1935 and began filling up that year. Note that the elevation in December 1935 and 1936 (see table) was only 908.40 feet and 1023.50 feet. Because Lake Mead was in the process of filling up in 1935-36, the actual record minimum elevation following the initial fill up up of the Lake occurred in 2010.
> The level of Lake Mead at Hoover Dam has risen 38.42 feet since the 2012 minimum.
> It took 19 years after the 1964 low point for Lake Mead to fill up again.
Photos of Lake Mead Full and Lake Mead at Current December 2012 Elevation
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Lake Mead when full.
Photo courtesy of the Bureau of Reclamation
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Lake Mead when full.
Photo courtesy of the Bureau of Reclamation
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| Looking back toward Lake Mead from near the spillway on the east side of the dam. Image © K. Dewey, SNR, UNL |
Lake Mead in December 2012 is down 95.4 feet from the 1998 peak elevation. The white rock is the "bathtub" ring for Lake Mead. The exposed rock is white due to salt deposits while submerged.
Image © K. Dewey, SNR, UNL
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April 1998: Elevation 1212.74 feet
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December 2012: Elevation 1120.36 feet
Photo: Ken Dewey, SNR
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The Phenomenal Growth of Las Vegas:
The recent rapid increase in both residents and tourists coming to Las Vegas placed a huge demand on water resources.
However this pace has dramatically slowed the past few years due to the large scale U.S. economic slowdown.
1905 -- Town of Las Vegas established by auctioning of land.
1911 -- The city of Las Vegas is incorporated.
1931 -- Hoover Dam construction begins in Black Canyon.
Clark County and Las Vegas Population 1910-2011
Clark County............................................................................ Las Vegas
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Decade |
Decade |
Annual |
Annual |
|
|
Decade |
Decade |
Annual |
Annual |
|
| |
Clark Co |
Population |
% |
Population |
% |
|
Las Vegas |
Population |
% |
Population |
% |
|
Year |
Population |
Increase |
Increase |
Increase |
Increase |
|
Population |
Increase |
Increase |
Increase |
Increase |
Year |
1910 |
N/A |
|
|
|
|
|
945 |
|
|
|
|
1910 |
1920 |
4,859 |
|
|
|
|
|
2,304 |
1,359 |
143.81% |
|
|
1920 |
1930 |
8,422 |
3,563 |
73.33% |
|
|
|
5,165 |
2,861 |
124.18% |
|
|
1930 |
1940 |
16,414 |
7,992 |
94.89% |
|
|
|
8,422 |
3,257 |
63.06% |
|
|
1940 |
1950 |
48,289 |
31,875 |
194.19% |
|
|
|
24,624 |
16,202 |
192.38% |
|
|
1950 |
1960 |
127,016 |
78,727 |
163.03% |
|
|
|
64,405 |
39,781 |
161.55% |
|
|
1960 |
1970 |
273,288 |
146,272 |
115.16% |
|
|
|
125,787 |
61,382 |
95.31% |
|
|
1970 |
1980 |
463,087 |
189,799 |
69.45% |
|
|
|
164,674 |
38,887 |
30.91% |
|
|
1980 |
1990 |
741,459 |
278,372 |
60.11% |
|
|
|
286,600 |
121,926 |
74.04% |
|
|
1990 |
1991 |
829,839 |
|
|
88,380 |
11.92% |
|
298,321 |
|
|
11,721 |
4.09% |
1991 |
1992 |
870,692 |
|
|
40,853 |
4.92% |
|
310,197 |
|
|
11,876 |
3.98% |
1992 |
1993 |
919,388 |
|
|
48,696 |
5.59% |
|
330,472 |
|
|
20,275 |
6.54% |
1993 |
1994 |
986,152 |
|
|
66,764 |
7.26% |
|
352,305 |
|
|
21,833 |
6.61% |
1994 |
1995 |
1,040,688 |
|
|
54,536 |
5.53% |
|
374,239 |
|
|
21,934 |
6.23% |
1995 |
1996 |
1,119,708 |
|
|
79,020 |
7.59% |
|
405,517 |
|
|
31,278 |
8.36% |
1996 |
1997 |
1,170,113 |
|
|
50,405 |
4.50% |
|
422,884 |
|
|
17,367 |
4.28% |
1997 |
1998 |
1,246,193 |
|
|
76,080 |
6.50% |
|
448,244 |
|
|
25,360 |
6.00% |
1998 |
1999 |
1,321,319 |
|
|
75,126 |
6.03% |
|
466,312 |
|
|
18,068 |
4.03% |
1999 |
2000 |
1,428,690 |
687,231 |
92.69% |
107,371 |
8.13% |
|
484,500 |
198,500 |
69.41% |
18,188 |
3.90% |
2000 |
2001 |
1,498,279 |
|
|
69,589 |
4.87% |
|
498,638 |
|
|
14,138 |
2.92% |
2001 |
2002 |
1,578,332 |
|
|
80,053 |
5.34% |
|
507,219 |
|
|
8,581 |
1.72% |
2002 |
2003 |
1,641,529 |
|
|
63,197 |
4.00% |
|
516,723 |
|
|
9,504 |
1.87% |
2003 |
2004 |
1,747,025 |
|
|
105,496 |
6.43% |
|
534,168 |
|
|
17,445 |
3.38% |
2004 |
2005 |
1,815,700 |
|
|
68,675 |
3.93% |
|
544,806 |
|
|
10,638 |
1.99% |
2005 |
2006 |
1,925,654 |
|
|
109,954 |
6.06% |
|
552,855 |
|
|
8,049 |
1.48% |
2006 |
2007 |
1,996,542 |
|
|
70,888 |
3.68% |
|
559,892 |
|
|
7,037 |
1.27% |
2007 |
2008 |
1,986,146 |
|
|
-10,396 |
-0.52% |
|
562,849 |
|
|
2,957 |
0.53% |
2008 |
2009 |
2,006,347 |
|
|
20,201 |
1.02% |
|
567,641 |
|
|
4,792 |
0.85% |
2009 |
2010 |
2,036,358 |
607,668 |
42.53% |
30,011 |
1.50% |
|
583,756 |
99,256 |
20.49% |
16,115 |
2.84% |
2010 |
2011 |
1,966,630 |
|
|
-69,728 |
-3.42% |
|
589,317 |
|
|
5,561 |
0.95% |
2011 |
Number of Visitors to Las Vegas (1970-2011):
Number of visitors to Las Vegas in 2011: 38,928,708.
Number of visitors to Las Vegas in 2010: 37,335,436
Number of visitors to Las Vegas in 2000: 35,849,691
Number of visitors to Las Vegas in 1990: 20,954,420
Number of visitors to Las Vegas in 1980: 11,941,524
Number of visitors to Las Vegas in 1970: 7,361,783
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