Thursday, March 22, 2018

National Drought Mitigation Center

August 2015 Drought and Impact Summary

Drought maintains grip on West, expands in South and Southeast


Drought at the end of August 2015 affected more populated areas than drought did a year earlier, which explains why, although the proportion of the contiguous 48 states in drought was nearly the same, the number of people in drought-affected areas was quite a bit higher in 2015.

By Brian Fuchs, NDMC Climatologist


August brought more drought to the contiguous United States, with 30.43 percent in drought at the end of the month, compared to 25.71 percent at the end of July. Severe drought increased from 17.17 to 18.72 percent, extreme drought increased from 8.79 to 10.71 percent, and exceptional drought increased from 2.83 to 3.00 percent. This is similar to the same time last year, when 32.78 percent of the area was in drought. At the end of August, just over 97 million people were in drought areas, compared to just under 76 million people a month earlier, and compared to 73 million people at this time last year.

Drought Outlook

For September, forecasters see little opportunity for drought in the western United States to improve. Drought across the southern Plains will continue to evolve and intensify, spreading into more of central and southern Texas and Mississippi. Improvements in Arizona, southern Florida, Georgia, and South Carolina are expected, with some areas seeing drought conditions eliminated completely. Dryness in the Northeast will linger, with potential for drought to expand to more of the region.


August temperatures were 2-4 degrees cooler than normal over much of the High Plains, Midwest, and western portions of the Mid-Atlantic states. Most other locations were warmer than normal, especially the West and Southwest, which were 2-4 degrees above normal.


Areas of the southern Plains and Gulf Coast were very dry in August, with parts of Louisiana and Mississippi recording 4-6 inches less precipitation than usual. Above-normal precipitation was recorded in portions of the Tennessee River Valley, with areas of northern Alabama, Tennessee, Georgia, southern Missouri and northern Florida 3-5 inches wetter than normal for the month. In the central United States, western Iowa, northeast Nebraska, South Dakota, and eastern Montana were 2-4 inches wetter than normal. The Mid-Atlantic and Northeast were 1-3 inches drier than normal in August.

Regional Overviews

Movers & Shakers for August 2015

Percent area
July 28, 2015
Percent area
Sept. 1, 2015
Status Percentage point change

Biggest increases in drought


0.00 14.49 moderate 14.49
4.45 severe 4.45
Florida 17.19 20.82 moderate 3.63
Georgia 22.88 27.05 moderate 4.17
Idaho 86.63 91.93 moderate 5.30
22.20 29.26 extreme 7.06
Louisiana 0.00 80.73 moderate 80.73
0.00 10.98 severe 10.98
28.91 severe 5.41
13.95 18.84 extreme 4.89
Nevada 11.08 15.93 exceptional 4.85
New Hampshire
0.00 7.91 moderate 7.91
New Jersey
0.00 17.03 moderate
North Carolina
17.54 33.70 moderate 16.16
Oklahoma 0.00 8,84 moderate 8.84
Oregon 48.31 67.28 extreme 18.97
Puerto Rico
49.63 63.82 moderate 14.19
38.27 44.96 severe 6.69
12.40 24.89 extreme 12.49
South Carolina
63.98 moderate 16.45
0.03 26.73 severe 26.70
Texas 9.65 24.76 moderate 24.11
0.00 9.99
severe 9.99
Washington 31.74 67.96 extreme 36.22
Wisconsin 0.00 3.47 moderate 3.47
Biggest improvements in drought


74.94 70.79 moderate 4.15
9.57 5.57 severe
Idaho 51.71 48.90 severe 3.62
Kansas 3.49 0.00 moderate 3.49
New Mexico
19.35 13.08 moderate 6.27
Rhode Island
26.42 17.32 moderate 9.10


Temperatures were 2-4 degrees above normal in August in the Northeast, with the warmest readings in and along the coastal regions from Maine to Long Island. Areas of Maryland, Pennsylvania, and western New York were slightly cooler than normal. Conditions were also dry. Departures were generally less than 1 inch below normal, but some drier areas were intermixed. Drought expanded slightly in August in the Northeast, as 3.26 percent of the region was in drought at the end of the month compared to 2.25 percent at the end of July.


The northern portion of the region was slightly cooler than usual, while the southern portion was slightly warmer than usual. An area of above-normal precipitation was recorded from central Florida to the north and west into Georgia, northern Alabama, northeast Mississippi and Tennessee. These areas were 1-4 inches wetter than normal for the month. Areas of the Florida Panhandle, southern Mississippi and southern Alabama were quite dry, as much as 2-4 inches below normal for August. Drought conditions expanded in the region, with 24.32 percent of the area in drought at the end of August compared to 17.88 percent a month earlier. Severe drought expanded to include 5.22 percent of the region, an increase of 2.24 percent for the month. A small area of south Florida, less than 1 percent of the region, remained in extreme drought.


Cooler-than-normal temperatures dominated the Midwest in August, with most areas 2-4 degrees below normal for the month. Precipitation was mixed, with the majority of the region, from northern Missouri and northern Illinois into Indiana and Ohio recording below-normal precipitation for the month, with departures of 1-3 inches common. Areas of northwest Iowa, northern Minnesota and Wisconsin were above normal, with some areas in Iowa 5 inches wetter than usual for the month. Drought is not an issue in this region, with just a small pocket of moderate drought in southwest Wisconsin.

High Plains

The cooler-than-normal temperatures extended into the High Plains, where most areas were 2-4 degrees below normal for the month. Scattered precipitation patterns brought above-normal rain to some areas, while others were dry. An area from northwest South Dakota into northeast Nebraska recorded the most rains, with most areas 1-3 inches above normal. The driest pockets were in northeast Kansas, southeast Nebraska and portions of central and western Kansas, where precipitation in some areas was up to 3 inches below normal for August. Drought is not an issue in this region, which had only a few abnormally dry areas at the end of August.


The northern portions of the Southern region were 2-4 degrees cooler than normal for August, while the southern and western portions were 4-6 degrees warmer than normal. It was dry through the region as a whole, with areas of Texas and Oklahoma up to 4 inches below normal for the month. Dry conditions were also observed in portions of Arkansas and Louisiana. After most of the drought being eliminated by good rains earlier in the year, drought covered 24.61 percent of the region at the end of August, compared to 0.34 percent at the end of July, and severe drought covered 7.93 percent of the region, compared to none in July. A small area of extreme drought was also introduced into east Texas.


Warmer-than-normal temperatures again dominated the region, with most areas 2-4 degrees above normal for the month. Portions of western Washington and Oregon welcomed precipitation in August and ended the month 2-3 inches above normal. Monsoonal patterns brought 1-2 inches more than normal rain to an area from Arizona to Utah, Nevada, and southern Idaho. Dry conditions returned to New Mexico and Colorado, which ended up 1-2 inches below normal for August. The month brought little change in drought, with 59.67 percent of the region in drought at the end of August compared to 60.09 percent at the end of July. Severe drought covered 42.69 percent of the area, up from 42.99 percent at the end of July, while extreme drought expanded from 22.24 to 26.73 percent of the region, and exceptional drought expanded from 7.17 to 7.62 percent of the region.



August 2015 Impacts Summary: West Coast faced wildfire, loss of wildlife, and economic effects

For August 2015, the Drought Impact Reporter logged the most impacts for California, Washington, and Oregon.
The categories with the most impacts in August 2015 were Water Supply & Quality (22.7%), Relief, Response and Restrictions (20%), and Plants & Wildlife (18.3%).
In addition to the West Coast, Texas and North Carolina registered impacts in August.
California reservoir storage has declined in each of the past four years, during the most recent drought.

By Denise Gutzmer, Drought Impact Specialist

The drought-parched western U.S. continued to battle immense wildfires in August, as lightning strikes sparked blazes that defied containment and produced massive plumes of smoke. Fish died in rivers from Washington State to California this summer, due to warm, low waters carrying too little oxygen. Drought conditions returned to Texas, bringing back restrictions on water use and elevating fire danger. States with the most impacts recorded in the Drought Impact Reporter in August were California with 79, Washington with 34 and Oregon with 27.

El Niño raising hopes for drought relief in California

The developing El Niño may become one of the strongest since 1950, raising hopes that it will ease California’s drought. However, officials cautioned that there is no guarantee that El Niño will bring precipitation, and that it would take more than one wet year to make up for four years of drought.  

Latest forecast suggests 'Godzilla El Niño' may be coming to California,” by Rong-Gong Lin II, Los Angeles Times, Aug. 13, 2015

Varying estimates put drought’s 2015 cost to California’s economy at $2.7 and $3.3 billion in 2015

Drought in 2015 has been estimated to cost California's economy $2.7 billion and the state’s agricultural sector $1.84 billion, said researchers from the University of California at Davis. Direct crop revenue losses come to $900 million and will cost dairy and livestock producers $350 million. Rice, alfalfa and corn production were most affected by the drought.

The largest portion of the loss estimate came from fallowing 542,000 acres due to lack of irrigation water, amounting to about 20 percent more land than was idled in 2014. With fewer acres in production, farm workers were expected to be out of 10,100 seasonal farm jobs. Including indirect job losses, the overall job loss figure climbed to 21,000.

Statewide, farmers were nearly 9 million acre-feet short of the 28 million acre-feet used in a typical year for irrigation. To keep crops alive, an additional 6 million acre-feet of groundwater was being pumped in 2015, withdrawing water at an unprecedented rate. Groundwater pumping this year has added an estimated $590 million to farmers’ costs, which has been figured into the estimated impact of $2.7 billion.

A Fresno State study of the California drought estimated that lost agricultural revenue in the Central Valley could reach $3.3 billion. Farmers are using more energy to pump groundwater for their crops.

 “California drought impact pegged at $2.7 billion,” by Dale Kasler and Phillip Reese, The Sacramento Bee, Aug. 18, 2015

Economic Analysis of the 2015 Drought For California Agriculture,” Aug. 17, 2015, full report

Drought fallowing half-million acres in California in 2015,” by Ellen Knickmeyer, Associated Press, San Jose Mercury News (Calif.), Aug. 18, 2015

Fresno State study says drought causes $3.3 billion in farm losses,” by Robert Rodriguez, The Fresno Bee (Calif.), Aug. 27, 2015

The Fresno State Drought Impact Study Project

High-value crops help California growers maintain revenue despite drought

California agricultural revenue was $33.524 billion in 2014, the second highest in state history, despite intense drought. Revenue was high due to the cultivation of more high-value crops, such as almonds, pistachios and wine grapes, which were irrigated with groundwater, according to a study by the Pacific Institute. The agricultural sector also employed about 417,000 people, another record high.

The state’s highest crop revenue ever occurred in 2013, also a drought year, at $34 billion.

“Despite drought, California has record high crop revenue,” by Ian James, The (Palm Springs, Calif.) Desert Sun, USA Today, Aug. 26, 2015

Impacts of California’s Ongoing Drought: Agriculture by the Pacific Institute

Toxic algae threatens Delta water quality

A large microcystis bloom has developed in the Sacramento-San Joaquin Delta, as evidenced by small flecks of bright green in the water. Microcystis is a type of blue-green algae that can produce toxins that in high concentrations are lethal to fish and people, though fortunately, it was not observed in such concentrations. The algae bloom was observed in the central and north parts of the Delta, and the highest microcystis concentrations were found nearest to the freshwater side of the salinity barrier.

Scientists from the University of California-Davis, state water agencies and federal research groups were monitoring the unique algae bloom and were unsure of the exact cause, but thought that the bloom was produced through a combination of factors related to the warmer, slower water flow. With winter’s snowpack delivering so little runoff, less water was flowing through the Delta, possibly allowing higher concentrations of nutrients from sewage, fertilizer and other pollutants to support the algae bloom. Roughly 25 million people from Napa to San Diego rely on fresh water from the Delta to some extent, as do growers on about 3 million acres of irrigated farmland.

“Unusual Delta algae bloom worries researchers,” by Ryan Sabalow, The Sacramento Bee, Aug. 25, 2015

Californians conserved water in July

California urban water use fell 31 percent in July, compared with water use in 2013, for a savings of more than 74 billion gallons. The 31 percent water savings exceeds the governor’s mandate for a 25 percent reduction in water use. About four in five of the state’s roughly 420 water districts met the 25 percent goal in July. Most big cities also made their conservation targets, but four water districts missed their target by more than 15 percent.

 “California residents cut water use 31 percent in July,” by Phillip Reese and Ryan Sabalow, The Sacramento Bee, Aug. 27, 2015

Shade balls deployed to protect water

Ninety-six million shade balls made from high-density polyethylene were dropped into the Los Angeles Reservoir to protect water quality, prevent algae growth and slow evaporation from the reservoirs. The L.A. Reservoir has a surface of 175 acres and contains more than 3.3 billion gallons of water, 300 million of which are expected to be prevented from evaporating annually, thanks to the shade balls. The project cost $34.5 million and was far cheaper than covering the reservoir with a more traditional protective cover. The plastic balls do not leach any chemicals and ought to last 10 years.

“Q&A Millions of shade balls helping protect California's precious water,” by Alice Walton, Los Angeles Times, Aug. 12, 2015

Drought created emergency for California’s trees

Water conservation in California has had an unintended effect: trees have gone unwatered and were showing signs of stress. Statewide, trees were dying, which will reduce habitat, shade and property values, prompting cities to act before more trees are lost. Species suffering the most along the Sierra’s western slopes included pine trees, especially Jeffrey, lodge pole, ponderosa, sugar and white bark varieties. In the canyons of the state’s Central Coast, Santa Lucia firs were dying at higher rates. The giant sequoia trees in Sequoia and Kings Canyon national parks were also affected by drought, with more dead foliage than usual in 2014 and 2015.

A researcher with UC Davis, who manages biodiversity data for the California Department of Fish and Wildlife, stated that the drought was transforming landscapes, promoting the establishment of chaparral over woodland.

“Drought sets up 'emergency situation' for California's trees,” by Lisa M. Krieger, San Jose Mercury News, Aug. 16, 2015

Who should get water during drought?

Most Americans think that farmers should be favored when deciding who gets water during drought and water restrictions, found a poll conducted by Associated Press-Gfk. Seventy percent of poll participants thought that the government should restrict how much water residents and businesses use amid drought. When asked to prioritize water use, 74 percent felt that agriculture ought to be a top or high priority, with residential needs coming in second (66 percent), wildlife and ecosystems third (54 percent) and business and industry fourth (42 percent). Participants’ responses were fairly similar across the nation.

“Poll: Americans favor farmers during drought,” by Associated Press, Klamath Falls Herald and News (Ore.), Aug. 4, 2015

California fish stressed by habitat loss, warm water

A key index of delta smelt abundance fell to zero in July because there were so few smelt in the Sacramento-San Joaquin Delta. The numbers of delta smelt have been declining for years due to invasive predators, pollution, habitat loss and increased water exports through the delta. Populations of other native fish species, such as longfin smelt, green sturgeon and winter-run Chinook salmon, were also struggling during the drought.

About 80,000 pounds of rainbow trout were moved from the San Joaquin Hatchery in Millerton Lake to the cooler water in Shaver Lake to save the fish from warm water temperatures, near 70 degrees. The first trout transport began on Aug. 12, and more trout will be moved to lakes in Fresno and Madera counties. This was the first time fish had to be rescued from warm waters of the San Joaquin Hatchery.

“Drought could hurt endangered fish caught in water fight,” by Terence Chea, Associated Press, Aug. 4, 2015

“Trout in trucks: Drought forces evacuation of San Joaquin Hatchery,” by Angel Moreno, The Fresno Bee, Aug. 12, 2015

Washington drought, heat killed hatchery fish

Roughly 1.5 million juvenile fish in more than 12 of Washington’s 83 fish hatcheries died from the summer drought and heat wave. Hatchery crews were using re-circulation pumps and aerators to cool the water, and, as a last resort, were moving fish to other hatcheries with cooler water. In some cases, the fish were given a medical feed to protect them against fungal and bacterial infections. Sockeye and chinook salmon attempting to spawn in the state’s rivers also faced obstacles.

“Hatchery crews working overtime to save as many fish as possible due to extreme drought-like conditions,” by Mark Yuasa, The Seattle Times, Aug 2, 2015

“Heat and drought devastate sockeye salmon fishing and spawning on Washington rivers,” by William Yardley, Los Angeles Times, Aug. 3, 2015

Texas returns to drought

Abundant rainfall in late spring pulled Texas out of drought for the most part in late spring and early summer, but dry conditions were quick to return. Water restrictions made a quick comeback in New Braunfels and San Antonio, too, as the Edwards Aquifer dropped quickly during the summer. Numerous Texas counties, from the Houston area through central and east Texas, adopted burn bans as the fire danger rose.

“Stage II Watering Restrictions a Matter of When, Not If.” KGNB 1420-AM (New Braunfels, Texas), Aug. 5, 2015

“SAWS announces Stage 2 water restrictions in effect,” KABB FOX 29 (San Antonio, Texas), Aug. 14, 2015

“Counties begin enacting burn bans,” by Gabrielle Banks and Mihir Zaveri, Houston Chronicle, Aug. 11, 2015

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