Report 2013–5018

Prepared in cooperation with the Oklahoma Water Resources Board

Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

Scientific Investigations Report 2013–5018

U.S. Department of the Interior U.S. Geological Survey Cover:

North Canadian River near Calumet, Oklahoma, during drought conditions in July 2011 (photograph by J.A. Savoia, U.S. Geological Survey). Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

By Molly J. Shivers and William J. Andrews

Prepared in cooperation with the Oklahoma Water Resources Board

Scientific Investigations Report 2013–5018

U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior SALLY JEWELL, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2013

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Suggested citation: Shivers, M.J., and Andrews, W.J., 2013, Hydrologic drought of water year 2011 compared to four major drought periods of the 20th century in Oklahoma: U.S. Geological Survey Scientific Investigations Report 2013-5018, 52 p., http://pubs.usgs.gov/sir/2013/5018/. iii

Acknowledgments

The authors would like to thank several people for their contributions to the data collection and data analysis presented in this report. Darrell Townsend and Wynema Potter of the Grand River Dam Authority provided hydroelectric power generation data for Grand Lake, Lake Hudson, and the Salina project on Chimney Rock Lake. Ashley Corker of the Southwestern Power Administra- tion provided hydroelectric power generation data for Fort Gibson Lake, Keystone Lake, Lake Eufaula, Lake Tenkiller, and Broken Bow Lake. Jennifer Rogers of the Oklahoma Municipal Power Authority provided hydroelectric power generation data for Kaw Lake. Gary McManus of the Oklahoma Climatological Survey provided customized maps of percentage of normal precipitation and departure from normal precipitation for water year 2011. U.S. Geological Survey personnel Jon Scott, S.J. Smith, and Joy Savoia provided low-flow and lake-level photographs taken in the late summer of 2011. iv

Contents

Abstract...... 1 Introduction...... 1 Selected Consequences of the 2011 Drought...... 2 Wildfires...... 2 Required Water Conservation, Burn Bans, and States of Emergency...... 2 Agriculture...... 2 Tourism...... 3 Wildlife...... 3 Purpose and Scope...... 3 Progression of Drought...... 3 Drought Sequence...... 3 Progression of Water Year 2011 Streamflow...... 3 Statewide Precipitation and Streamflow...... 4 Precipitation by Climate Division...... 14 Climate Division 1 Panhandle...... 14 Climate Division 2 North Central...... 16 Climate Division 3 Northeast...... 16 Climate Division 4 West Central...... 16 Climate Division 5 Central...... 16 Climate Division 6 East Central...... 16 Climate Division 7 Southwest...... 16 Climate Division 8 South Central...... 16 Climate Division 9 Southeast...... 16 Streamflow of Long-Term Stations...... 16 Salt Fork Arkansas River at Tonkawa...... 20 Chikaskia River near Blackwell...... 20 Cimarron River near Waynoka...... 20 Cimarron River near Ripley...... 20 Illinois River near Tahlequah...... 20 Canadian River at Calvin...... 26 North Canadian River near Wetumka...... 26 Salt Fork Red River at Mangum...... 26 Red River near Gainesville, Texas...... 26 Washita River near Dickson...... 26 Blue River near Blue...... 26 Red River at Arthur City, Texas...... 33 Effects of Low Streamflows...... 33 Conditions at Major Reservoirs...... 33 Hydroelectric Power Generation...... 33 Groundwater Levels at Selected Long-term Stations...... 33 Summary...... 41 References...... 41 Appendixes 1–4. Photographs of Selected Sites at Normal/High-Flow Conditions and Drought/Low-Flow Conditions, 2007–12...... 47 v

Figures

1. Schematic diagram showing sequence of drought development...... 4 2. Map showing monthly streamflow by percentile class, from U.S. Geological Survey WaterWatch, October 2010 through September 2011...... 6 3. Barchart showing annual departure from the statewide long-term median annual precipitation of 33.62 inches and a 5-year weighted average for Oklahoma, water years 1925–2011...... 8 4. Barchart showing annual departure from the statewide long-term median annual runoff of 2.74 inches and a 5-year weighted average for Oklahoma, water years 1925–2011...... 11 5. Maps showing water resources regions and regional streamflow levels in water year 2011...... 12 6. Graph showing percentage of streamflow-gaging stations with below-normal streamflow from January 16, 2001, through December 31, 2011, in Oklahoma...... 13 7. Map showing National Weather Service Climate Divisions in Oklahoma...... 14 8. Maps showing percentage of normal precipitation A, and departure from normal precipitation B, for Oklahoma, water year 2011...... 15 9. Map showing selected long-term streamflow-gaging stations in Oklahoma and appendix photograph locations...... 17 10. Barchart and graph showing streamflow data for Salt Fork Arkansas River at Tonkawa, Oklahoma, water years 1942–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow...... 21 11. Barchart and graph showing streamflow data for Chikaskia River near Blackwell, Oklahoma, water years 1937–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow...... 22 12. Barchart and graph showing streamflow data for Cimarron River near Waynoka, Oklahoma, water years 1938–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow...... 23 13. Barchart and graph showing streamflow data for Cimarron River near Ripley, Oklahoma, water years 1940–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow ...... 24 14. Barchart and graph showing streamflow data for Illinois River near Tahlequah, Oklahoma, water years 1936–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow...... 25 15. Barchart and graph showing streamflow data for Canadian River at Calvin, Oklahoma, water years 1939–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow...... 27 16. Barchart and graph showing streamflow data for North Canadian River near Wetumka, Oklahoma, water years 1938–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow...... 28 vi

17. Barchart and graph showing streamflow data for Salt Fork Red River at Mangum, Oklahoma, water years 1938–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow...... 29 18. Barchart and graph showing streamflow data for Red River near Gainesville, Texas, water years 1937–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow ...... 30 19. Barchart and graph showing streamflow data for Washita River near Dickson, Oklahoma, water years 1929–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow...... 31 20. Barchart and graph showing streamflow data for Blue River near Blue, Oklahoma, water years 1937–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow...... 32 21. Barchart and graph showing streamflow data for Red River at Arthur City, Texas, water years 1945–2011. A, Annual departure from long-term median annual streamflow. B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow...... 34 22. Map showing locations of selected major Oklahoma lakes and reservoirs and percentage of conservation storage as of September 29, 2011...... 36 23. Graphs showing A, Daily-mean water levels, water year 2011 and B, Long-term daily mean water levels and all water levels measured in a groundwater well near Fittstown, Oklahoma, water years 1958–2012...... 38 24. Graphs showing A, Daily-mean water levels, water year 2011; long-term daily mean water levels; and B, Continuously recorded water levels measured in a groundwater well in Johnston County, Oklahoma, water years 2006–11...... 39 25. Graphs showing A, Daily-mean water levels, water year 2011; B, Long-term daily-mean water levels; and continuously recorded water levels measured in a groundwater well near Texhoma, Oklahoma, water years 1956–2011...... 40

Tables

1. Summary of precipitation at National Weather Service Climate Divisions in Oklahoma comparing the median of mean annual precipitation during water years 1925–2006 with average annual precipitation during periods of previously documented hydrologic droughts and the recent hydrologic drought period...... 9 2. Summary of streamflow conditions at selected long-term streamflow-gaging stations in Oklahoma comparing the median of mean annual streamflow (measure of “normal” streamflow) with average annual streamflow during periods of previously documented hydrologic droughts and the recent hydrologic drought period...... 18 3. Storage in selected major Oklahoma lakes and reservoirs on September 29, 2011, by National Weather Service Climate Division, and comparison with April 14, 2011, storage...... 35 4. Comparison of hydroelectric power generation at selected Oklahoma hydroelectric plants between calendar years 2010 and 2011...... 37 vii

Conversion Factors Inch/Pound to SI Multiply By To obtain Length inch (in.) 2.54 centimeter (cm) inch (in.) 25.4 millimeter (mm) foot (ft) 0.3048 meter (m) mile (mi) 1.609 kilometer (km) Area square mile (mi2) 2.590 square kilometer (km2) acre 0.4047 hectare (ha) Volume acre-foot (acre-ft) 1,233 cubic meter (m3) Flow rate cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s) Energy gigawatt-hour (GWh) 3.6 x 1012 joule (J)

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows: °C=(°F-32)×.56 Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88). Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83). Altitude, as used in this report, refers to distance above the vertical datum. Water year is the 12-month period October 1 through September 30, designated by the calendar year in which it ends

Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

By Molly J. Shivers and William J. Andrews

Abstract from 43 to 76 percent of normal annual precipitation, with the Northeast Climate Division having the closest to normal Water year 2011 (October 1, 2010, through September 30, precipitation and the Southwest Climate Division having the 2011) was a year of hydrologic drought (based on streamflow) greatest percentage of annual deficit. Based on precipitation in Oklahoma and the second-driest year to date (based on amounts, water year 2011 ranked as the second driest of the precipitation) since 1925. Drought conditions worsened 1925–2011 period, being exceeded only in one year of the substantially in the summer, with the highest monthly average 1952 to 1956 drought period. temperature record for all States being broken by Oklahoma in Regional streamflow patterns for water year 2011 indicate July (89.1 degrees Fahrenheit), June being the second hottest that streamflow in the Arkansas-White-Red water resources and August being the hottest on record for those months region, which includes all of Oklahoma, was relatively large, for the State since 1895. Drought conditions continued into being only the 26th lowest since 1930, primarily because the fall, with all of the State continuing to be in severe to of normal or above-normal streamflow in the northern part exceptional drought through the end of September. In addition of the region. Twelve long-term streamflow-gaging stations to effects on streamflow and reservoirs, the 2011 drought with periods of record ranging from 67 to 83 years were increased damage from wildfires, led to declarations of states selected to show how streamflow deficits varied by region of emergency, water-use restrictions, and outdoor burning in Oklahoma. Statewide, streamflow in water year 2011 was bans; caused at least $2 billion of losses in the agricultural greater than streamflows measured in years during the drought sector and higher prices for food and other agricultural periods of 1929–41, 1952–56, 1961–72, and 1976–81. The products; caused losses of tourism and wildlife; reduced hydrologic drought worsened going from the northeast toward hydropower generation; and lowered groundwater levels in the southwest in Oklahoma, ranging from 140 percent (above State aquifers. normal streamflow) in the northeast, to 13 percent of normal The U.S. Geological Survey, in cooperation with the streamflow in southwestern Oklahoma. The relatively low Oklahoma Water Resources Board, conducted an investigation streamflow in 2011 resulted in 83.3 percent of the statewide to compare the severity of the 2011 drought with four previous conservation storage being available at the end of the water major hydrologic drought periods during the 20th century – year in major reservoirs, similar to conservation storage in water years 1929–41, 1952–56, 1961–72, and 1976–81. the preceding severe drought year of 2006. The ranking of The period of water years 1925–2011 was selected as the streamflow as the 16th smallest for the 1925–2011 period, period of record because few continuous record streamflow- despite precipitation being ranked the 2d smallest, may have gaging stations existed before 1925, and gaps in time existed been caused, in part, by the relatively large streamflow in where no streamflow-gaging stations were operated before northeastern Oklahoma during water year 2011. 1925. In water year 2011, statewide annual precipitation was the 2d lowest, statewide annual streamflow was 16th lowest, and statewide annual runoff was 42d lowest of those 87 years of record. Introduction Annual area-averaged precipitation totals by the nine National Weather Service climate divisions from water year Water year 2011 (October 1, 2010, through September 2011 were compared to those during four previous major 30, 2011) was a year of hydrologic drought (based on hydrologic drought periods to show how precipitation deficits streamflow) in Oklahoma, which had the second-driest year in Oklahoma varied by region. The nine climate divisions to date (based on precipitation) recorded since 1925. In in Oklahoma had precipitation in water year 2011 ranging Oklahoma, the drought was characterized by below-normal 2 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma precipitation beginning in the fall and persisting through most Required Water Conservation, Burn Bans, and of the remainder of the year, punctuated by some wet periods States of Emergency in eastern Oklahoma in the spring and summer. Drought conditions worsened substantially in the summer, breaking Declining streamflow and lake levels and limited the all-time July statewide average temperature record for pumping infrastructure caused some Oklahoma water- all States (89.1 degrees Fahrenheit [°F]). Statewide average suppliers to issue mandatory water-conservation measures temperatures in June were the second hottest on record for during the summer of 2011. On June 29, the City of Goldsby banned all outdoor watering because of lowered production that month (83.5°F), and temperatures in August (87.7°F) from a city well (KWTV, 2011a). On July 7, Logan County were the hottest on record for that month in Oklahoma since Rural Water District 1 banned lawn watering (KOTV, 2011). 1895 (Oklahoma Climatological Survey 2010a–c, 2011a–i). On July 9, Oklahoma City instituted a mandatory odd/even Drought conditions continued into the fall, with all of the outdoor watering program based on dates and street addresses State undergoing severe to exceptional drought through the (Hertneky, 2011). Oklahoma City’s outdoor watering end of September (U.S. Drought Monitor, 2011). This drought restrictions ended on August 11 after storms increased water was caused primarily by weather patterns associated with La levels in the city’s water-supply lakes (Overholser and Hefner) Niña conditions in the Pacific Ocean (National Oceanic and (KWTV, 2011b). As of September 7, 2011, 40 of 113 public Atmospheric Administration (2011). To assist water-resource water-supply systems surveyed had declared mandatory water- managers in evaluating the severity of the water year 2011 use restrictions and 45 of those systems had asked customers hydrologic drought and in planning for future droughts, the to voluntarily restrict water use (Oklahoma Department of U.S. Geological Survey, in cooperation with the Oklahoma Environmental Quality, 2011). Water Resources Board, conducted a study to summarize the In Oklahoma, burn bans which prohibit outdoor burning, but not cooking, can be issued by counties or the water year 2011 hydrologic drought and compare it to the Governor. Burn bans were issued locally and by the Governor four previous major hydrologic drought periods of the 20th for counties across the State through the water year to century: (1929–41, 1952–56, 1961–72, and 1976–81). prevent wildfires (Oklahoma Office of Secretary of State, Hydrologic drought is associated with the effects of 2011a and b). periods of below-normal precipitation on surface or subsurface As of April 6, 2011, 47 of 77 counties in Oklahoma water supplies. The severity of hydrologic drought is defined had issued burn bans to prevent wildfires (KJRH, 2011). on a watershed or river-basin scale. Water in hydrologic On August 3, 2011, Governor Mary Fallin extended a storage systems of rivers and reservoirs commonly has 45-county burn ban issued on July 15, 2011, to all 77 counties multiple and competing purposes including flood control, in Oklahoma (Hayes, 2011b). After precipitation in late irrigation, recreation, navigation, hydropower generation, September, Governor Fallin lifted the burn ban for 33 counties and wildlife habitat. Competition for river and reservoir in the central and northern parts of Oklahoma (Associated water escalates during droughts, and conflicts between Press, 2011). On June 24, 2011, Oklahoma Lieutenant Governor water users can increase substantially (National Drought Todd Lamb, at the request of Governor Fallin, declared a Mitigation Center, 2012a). Some of the consequences of the 30-day state of emergency for 33 counties in northwestern, water year 2011 drought in Oklahoma are described in the central, and southern parts of the State because of extreme following sections. or exceptional drought conditions and associated wildfires (Oklahoma Office of Secretary of State, 2011a). On September Selected Consequences of the 2011 Drought 19, 2011, Governor Fallin amended the first declaration by issuing a 60-day state of emergency for all 77 counties in Oklahoma for exceptional drought conditions and numerous wildfires (Oklahoma Office of Secretary of State, 2011b). Wildfires

Wildfires were a notable feature of the 2011 drought. Agriculture Wildfires burned several hundred buildings and almost In 2010, Oklahoma ranked first in production of rye, 300,000 acres in Oklahoma in 2011 (Cable News Network, second in production of beef cattle, and third in production 2011a and b; Dean and others, 2011; Olafson, 2011; Richter, of winter wheat in the United States (Oklahoma Department 2011; National Interagency Fire Center, 2012). Additional of Agriculture, Food, and Forestry, 2011). The 2011 drought effects of wildfires included closure of nearby highways and caused losses in crops and livestock in Oklahoma exceeding evacuations of rural and urban residents in potential wildfire $1.6 billion (Hayes, 2011c). From April through September, paths (Cable News Network, 2011b; Olafson, 2011; soils in the State were rated as abnormally to severely dry and Richter, 2011). many cropland areas and pasture were being rated in the fair to Introduction 3 very poor range (Oklahoma Water Resources Board, 2011d–j). Purpose and Scope Li and Hiatt (2012) estimated from satellite imagery that crop and pasture biomass losses ranged from 1.2 to 2 tons per acre The purposes of this report are to describe and document over much of the State. Compared to 2010, production of the water year 2011 hydrologic drought in Oklahoma and corn, grain sorghum, cotton, soybeans, sunflowers, and hay in effects of that drought and to compare the 2011 hydrologic 2011 decreased 61, 87, 85, 71, 69, and 61 percent, respectively drought to four previous major hydrologic drought periods of (National Agricultural Statistics Service, 2012a). Cotton water years 1929–41, 1952–56, 1961–72, and 1976–81. acreage harvested in Oklahoma in 2011 was the smallest since This report includes: (1) a definition of drought 1894 (Hayes, 2011d). Resulting high feed and hay prices and sequence, (2) a presentation of monthly nationwide steamflow displayed in U.S. Geological Survey WaterWatch graphics for dry ponds forced many ranchers to sell cattle, thereby causing water year 2011, and (3) a comparison of annual statewide a reduction of about 12 percent of the State cattle inventory total precipitation and statewide runoff (measurement of by the end of 2011, which contributed to record cattle prices streamflows greater than base flows that are related to storm by the end of the year and the smallest cattle inventories in intensity) from water years 1925–2011 in Oklahoma with the the State since 1968 (Hayes, 2011d; National Agricultural four previous major hydrologic droughts of the 20th century Statistics Service, 2012b). highlighted. Annual area-averaged precipitation totals for water year 2011 for the nine National Weather Service Climate Tourism Divisions in Oklahoma are compared to precipitation during four previous major hydrologic droughts in the 20th century to Tourism, the third largest industry in Oklahoma, show how precipitation deficits varied from normal by region. generates more than $6.1 billion annually in expenditures and Mean annual streamflows during water year 2011 at 12 long- employs nearly 76,000 people in the State (Oklahoma Tourism term streamflow-gaging stations are compared to streamflows and Recreation Department, 2011). Much of the tourism in during four previous major hydrologic droughts of the 20th Oklahoma is associated with outdoor recreation on streams century to show how streamflow deficits from the median and lakes at State parks and elsewhere (Oklahoma Tourism varied by region. Effects of the 2011 drought are described, including: (1) increased wildfires, (2) increased mandates for and Recreation Department, 2011). Decreased streamflow water conservation and outdoor burning bans, (3) reduced and lake levels likely decreased receipts from water-related crop yields and sell-offs of cattle herds, (4) reduced tourism, tourism in 2011 (Severson and Johnson, 2011). Warnings and (5) increased mortality of wildlife, (6) reduced streamflow beach closures enacted because of potentially toxic blooms and conservation storage at major reservoirs in the State, (7) of blue-green algae (Cyanophyta) in warm, stagnant water at reduced hydroelectric power generation, and (8) decreased many of the State’s largest reservoirs during the summer also groundwater levels in major aquifers. decreased tourism (Murphy, 2011; Sewell, 2011; Lawrence, 2012). Progression of Drought Wildlife

In addition to effects on humans and livestock, the Drought Sequence drought conditions and wildfires of 2011 caused wildlife to Drought-sequence development is illustrated in figure have health problems and suffer from increased mortality. 1. A drought begins with precipitation deficiency, high Deer in Texas and Oklahoma had lower rates of reproduction temperatures and winds, and low humidity, collectively and survival, and fawns and deer were in poorer condition, resulting in “meteorological” drought. As soil moisture as shown by smaller antler sizes (Medley, 2011a; Ray, 2011). is reduced and plants are stressed, “agricultural” drought Increased numbers of dehydrated baby squirrels prematurely occurs. If the drought continues for several seasons, left nests (Medley, 2011a). Fledgling avian wildlife such streamflow is reduced to critical levels and “hydrologic” as hawks and kites died in above-normal numbers from drought results (National Drought Mitigation Center, 2012a). hyperthermia and thirst (Medley, 2011a). The quail population across the State in 2011 was estimated to have decreased 25 percent from the population surveyed in 2010 (Schoeling, Progression of Water Year 2011 Streamflow 2011). Freshwater mussels, including three threatened species, The WaterWatch Webpage of the U.S. Geological suffered increased mortality as streams and rivers dried up in Survey maps monthly streamflow across the United States southeastern Oklahoma (Vaughn and Atkinson, 2012). Lack by percentile class (U.S. Geological Survey, 2012a). The 50th of berries, acorns, and water caused by the drought forced percentile represents the median monthly streamflow for black bears in eastern Oklahoma to scavenge at higher rates in the period of record, and normal streamflow is represented suburbs and towns (Medley, 2011b). by the 25th to 75th percentiles of long-term median 4 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

Natural climate variability

Precipitation deficiency High temperature and winds (amount, intensity, timing) Low humidity Greater sunshine Reduced runoff Less cloud cover

Reduced infiltration and percolation drought Reduced groundwater recharge Increased evaporation and transpiration Meteorological

Soil water deficiency

Plant water stress Reduced biomass and yield drought Agricultural Time duration Time

Reduced streamflow Reduced inflow to reservoirs, lakes, and ponds

Reduced wetlands and wildlife habitats drought Hydrologic

Economic effects Social effects Environmental effects

(Oklahoma Water Resources Board, 2007a; modified from National Drought Mitigation Center, 2012b)

Figure 1. Sequence of drought development.

monthly streamflow. Figure 2 shows the ranges of streamflow Statewide Precipitation and Streamflow in major basins in the United States, ranging from red tones for below long-term normal streamflow to blue tones Graphs of precipitation and estimated runoff of for above long-term normal streamflow. Streamflow in precipitation characterize the duration and severity Oklahoma was normal for most of the State from October of hydrologic drought by comparing annual statewide through December 2010, but below-normal streamflow and precipitation and runoff departures from long-term median annual precipitation values. Annual departures are shown much-below-normal streamflow increased from the southeast as positive bars when values exceed the long-term median and northwest to include much of the State through the annual precipitation and as negative bars when values remainder of water year 2011 (fig. 2). The most widespread are less than the long-term median-annual precipitation. occurrence of much-below-normal streamflow during the Departures that are consistently negative over several water year was measured during July 2011, when much- years provide a measure of drought duration or persistence, below-normal streamflows were measured in about two- whereas the magnitudes of individual departures provide thirds of the State (fig. 2). measures of severity. Introduction 5

The period of water years 1925–2011 was selected as the most regions in terms of runoff (Nace and Pluhowski, 1965; period of record for long-term drought analysis. Before 1925 Tortorelli and others, 1991) (figs. 3 and 4). few continuous record streamflow-gaging stations existed, The hydrologic drought of water years 1961–72 was as and there were gaps when no streamflow gaging stations widespread and lasted longer than the drought of 1952–56 but were operated in many parts of the State (U.S. Geological generally was not as severe (Tortorelli and others, 1991) (figs. Survey, 2012b–c). Four previous major hydrologic drought 3 and 4). By 1972, many of the major reservoirs in Oklahoma periods of water years 1929–41, 1952–56, 1961–72, and built to augment water supplies during periodic droughts had 1976–81 were identified from statewide runoff (Tortorelli been completed (Vance, 2007). The hydrologic drought of and others, 1991; Tortorelli, 2008). water years 1976–81 also was widespread, but was neither as Figures 3 and 4 show annual statewide median severe nor as persistent as the previous three major drought precipitation and annual statewide median runoff, periods (Tortorelli and others, 1991) (figs. 3 and 4). respectively, during water years 1925–2011. In figure 3, the Although Tortorelli (2008) described a drought period statewide annual median precipitation for each water year of for water years 2002–2006, that period was neither as long- that period (National Climatic Data Center, 2012a) is plotted lasting nor as severe as the four previous drought periods as departure from the long-term median annual precipitation of the 20th century. In 2006, however, the drought was for the period (blue line), and a 5-year weighted-average precipitation is plotted as a red line. Statewide, water year as severe as it had been in previous periods (figs. 3 and 2011 was the second driest in the 87 years of record from 4). Record large rainfalls occurred during the summer of 1925–2011, based on precipitation (fig. 3, table 1). In figure 2007 in some parts of the state, with the subsequent years 4, the statewide annual median runoff for each water year of 2008–10 having gradual decreases in above-normal of the period (U.S. Geological Survey, 2012d) is plotted as precipitation and runoff (figs. 3 and 4). Water years 2006 the departure from the long-term median annual runoff for and 2011 were exceptionally dry years in an otherwise the period (blue line), and a 5-year weighted-average runoff normal-to-wet period. is plotted as a red line. In both figures 3 and 4, selected Based on runoff, which increases with more intensive drought periods are indicated by differently colored bars. precipitation, water year 2011 was the 42d driest in the 87 Statewide runoff in water year 2011 was the 42d smallest years of record from 1925–2011 (fig. 4). Average statewide in the 87 years of record from 1925–2011 (fig. 4). In figures precipitation was the 2d lowest and average annual 3 and 4, wetter years have bars above the median line and streamflow was the 16th lowest during the 1925–2011 study drier years have bars below the median line. The severity period (tables 1 and 2; figs. 3 and 4). Drought conditions of drought conditions in water year 2011 can be compared in water year 2011 were severe, but drought duration or to the four previous major hydrologic droughts by the depth persistence of water year 2011 cannot yet be characterized, as of the bars representing dry years. The severity of the water of December 2012. year 2011 drought also can be compared to the four previous Regional streamflow patterns for water year 2011 major hydrologic drought periods by the 5-year weighted (fig. 5) indicate that streamflow in the Arkansas-White-Red average line. water resources region, which includes all of Oklahoma, was Comparison of the 2011 drought with previous drought the 26th driest since 1930 (U.S. Geological Survey, 2012e). periods is useful for putting the extent and severity of the The general pattern of greater-than-normal precipitation 2011 drought in context. The hydrologic drought of water in the northern tier of States and less-than-normal years 1929–41 was known as the “Dust Bowl” in the Great precipitation in the southern tier of States is common to Plains and is documented in many references, including Hoyt seasonal precipitation patterns in autumn, winter, and spring (1936, 1938), Nace and Pluhowski (1965), Egan (2006), and (National Weather Service, 2012). Normal or above-normal National Drought Mitigation Center (2012b). The drought of the “Dust Bowl” years was particularly severe in western precipitation in northern parts of the Arkansas-White- Oklahoma, with substantial runoff deficits of 2–3 inches Red water resources region contributed to near-normal per year and significant wind erosion over the entire State streamflow in the region, despite much drier conditions in the in 1936 (Nace and Pluhowski, 1965) (fig. 4). The 1929–41 southern part of the region. As an indicator of progression of drought led to development of nationwide soil conservation the hydrologic drought during water year 2011, for some days measures (National Drought Mitigation Center, 2012b). in November 2010 almost 50 percent of long-term (having Despite the widely known effects of the “Dust Bowl” at least 30 years of record) streamflow-gaging stations had of the 1930s, the lesser-known hydrologic drought of water below-normal streamflow (fig. 6). In August 2011, near the years 1952–56 was more severe. The drought of the mid- peak of drought conditions (fig. 2), almost 90 percent of 1950s was the most widespread and the most severe for long-term streamflow-gaging stations in the state had below- all regions of Oklahoma in terms of precipitation and for normal streamflow (fig. 6). 6 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

October 2010 November 2010

December 2010 January 2011

February 2011 March 2011

EXPLANATION Percentile classes

Low <10 10–24 25–75 76–90 >90 High No data U.S. Geological Survey (2012a) Much Below Normal Above Much below normal normal above normal normal

Figure 2. Monthly streamflow by percentile class, from U.S. Geological Survey WaterWatch, October 2010 through September 2011. Introduction 7

April 2011 May 2011

June 2011 July 2011

August 2011 September 2011

EXPLANATION Percentile classes

Low <10 10–24 25–75 76–90 >90 High No data U.S. Geological Survey (2012a) Much Below Normal Above Much below normal normal above normal normal

Figure 2. Monthly streamflow by percentile class, from U.S. Geological Survey WaterWatch, October 2010 through September 2011—Continued. 8 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma 0 1 0 2 s e c h n i 0

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Annual departure from the statewide long-term median annual precipitation of 33.62 inches and a 5-year weighted average for Okl ahoma, water years 1925–2011.

r a e y r e p s e h c n i n i , n o i t a t i p i c e r p l a u n n a

n a i d e m m o r f e r u t r a p e d l a u n n A Figure 3. Introduction 9

Table 1. Summary of precipitation at National Weather Service Climate Divisions in Oklahoma comparing the median of mean annual precipitation during water years 1925–2006 (measure of “normal” precipitation) with average annual precipitation during periods of previously documented hydrologic droughts (1929–41, 1952–56, 1961–72, 1976–81) and the recent (2011) hydrologic drought period.

[avg, average; rank, rank of driest year of drought period compared to period of record for water years 1925–2006; WY, water year; SW, statewide]

Hydrologic drought periods Long-term 11929–41 11952–56 Climate Climate annual Lowest year/rank Lowest year/rank division division median Long-term Long-term WY avg annual WY avg annual number name precipitation median median precipitation precipitation (inches) precipitation precipitation (inches) (inches) (percent) (percent) SW Statewide2 33.62 1936 6 1956 1 25.24 75 18.68 56 1 Panhandle3 19.84 1937 3 1956 2 12.24 62 11.34 57 2 North Central3 28.79 1936 8 1956 1 20.16 70 15.10 52 3 Northeast3 39.96 1939 13 1956 1 30.59 77 22.90 57 4 West Central3 26.39 1940 13 1952 3 20.14 76 15.98 61 5 Central3 34.33 1936 5 1956 2 24.03 70 19.74 58 6 East Central3 43.33 1936 4 1956 1 28.11 65 23.86 55 7 Southwest3 27.88 1939 8 1956 2 18.75 67 17.45 63 8 South Central3 37.47 1939 4 1956 1 24.19 65 16.46 44 9 Southeast3 48.13 1934 3 1956 1 30.86 64 25.10 52 10 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

[avg, average; rank, rank of driest year of drought period compared to period of record for water years 1925–2006; WY, water year; SW, statewide]

Hydrologic drought periods 11961–72 11976–81 2011 Climate Lowest year/rank Lowest year/rank division Rank long- Long-term Long-term WY avg annual number WY avg annual WY avg annual term median median median precipitation precipitation precipitation precipitation precipitation precipitation (inches) (inches) (inches) (percent) (percent) (percent) SW 1963 4 1978 11 2 24.60 73 27.11 81 20.05 60 1 1970 6 1976 38 1 13.05 66 17.58 89 11.09 56 2 1966 7 1976 21 4 20.15 70 23.24 81 17.96 62 3 1963 2 1981 21 11 24.81 62 32.89 82 30.17 76 4 1970 5 1976 34 1 18.00 68 22.23 84 12.65 48 5 1972 10 1976 12 1 25.08 73 25.41 74 19.59 57 6 1963 5 1980 8 2 28.24 65 30.30 70 26.08 60 7 1967 3 1980 33 1 17.46 63 23.40 84 12.05 43 8 1963 8 1978 13 2 25.15 67 27.78 74 18.86 50 9 1963 9 1978 5 4 35.02 73 31.95 66 31.51 65 1Documented drought periods are modified from Tortorelli and others (1991). 2Ranks from Statewide Monthly Precipitation Totals, National Climatic Data Center (2012a). 3Ranks from Climate Division Monthly Precipitation Totals, National Climatic Data Center (2012b). Introduction 11 0 1 0 2 0 0 0 2 s 0 e 9 9 1 c h n i

4 7 . 2

f f 1 o 0 8 8 n – 9 6 r u 1 7

l 9 e a 1 g u a n r

a n

n a v e 0

e 2 a r 7 i d 7 9 u d e – t 1 t r 1 h a 6 y e a r m e g 9

p i EXPLANATION 1 m e r d e r

w e l

a t t e r a

u g 0

n 6

n y e

n 9

o -

A L 5

6 5 – 2 5 9 1

1 f o n

r u

0 1

d 4 1 1 9 0 4 1 – – 2 9 2 5 9 2 1 9

s t a e w i 1 : c i t s 0 g 3 h m a o 9 g l 1 o u o r o

a h

d r y

Below normal Below Above normal Above H O k l 0 2 9

0 8 6 4 2 0

1 - 2 - 4

1 Annual departure from the statewide long-term median annual runoff of 2.74 inches and a 5-year weighted average for Oklahoma, w ater years 1925–2011.

r a e y r e p s e h c n i n i , f f o n u r

l a u n n a n a i d e m m o r f e r u t r a p e d l a u n n A Figure 4. 12 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

The United States (including Puerto Rico) is divided into 21 large drainages, or water resources regions. These hydrologic areas are based on surface topography and contain either the drainage area of a major river, such as the Columbia, the combined drainage areas of a series of rivers, such as the Texas-Gulf region, which includes a number of rivers draining into the Gulf of Mexico, or the area of an island or island group. Water resources regions provide a coherent, watershed-based framework for depicting streamflow variations.

Streamflow was at record high levels (ranking 1st in 82 years) in the water resource regions of the Souris-Red-Rainy and Mid-Atlantic regions. Above normal and much-above normal streamflow occurred in all northeastern, northern, and western regions, and in the Caribbean. In contrast, streamflow was at record low levels (ranking 82nd in 82 years) in the South Atlantic-Gulf, Texas-Gulf, and Alaska regions, respectively. Below-normal and much-below normals were reported in the Lower Mississippi and Rio Grande regions.

EXPLANATION Rank

82 70–81 59–69 59–42 9–41 2–8 Highest Lowest Much Below Normal Above Much below normal normal above normal normal U.S. Geological Survey (2012e)

Figure 5. Water resources regions and regional streamflow levels in water year 2011. Introduction 13

Percentage of streamflow-gaging stations with below-normal streamflow 0

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Year

EXPLANATION The percent of streamflow-gaging stations with below-normal streamflow, plotted as the blue line in the above graph, is calculated each day as the percent of streamflow-gaging stations having below-normal flow, where the lower boundary for normal is the 25th percentile value of all historical streamflow values for all days of the year. The percent of stations with below-normal streamflow is based only on streamflow-gaging stations in the state having at least 30 years of record (U.S. Geological Survey, 2012f).

Figure 6. Percentage of streamflow-gaging stations with below-normal streamflow from January 16, 2001, through December 31, 2011, in Oklahoma. 14 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

Precipitation by Climate Division station is located in each of the 77 counties in Oklahoma. Oklahoma Mesonet climate data have been available since Oklahoma has nine National Weather Service Climate 1994. In addition to data from the Mesonet, data from Divisions (fig. 7) for which monthly area-averaged National Weather Service Stations (National Climatic Data precipitation data are available (National Climatic Data Center, 2012a) were used for the period 1925–2011. Mesonet Center, 2012a). Those data were totaled for each water year data use mean annual precipitation from calendar years from 1925–2011, indicating annual precipitation in Oklahoma 1971–2000 instead of median annual precipitation from water on a regional basis. years 1925–2011 for comparisons of long-term data. The Precipitation in the nine climate divisions of Oklahoma 1971–2000 period contained a significant wet period (fig. 3); in water year 2011 was substantially less than the long-term therefore, data presented on the Mesonet Website (fig. A8 ) median annual precipitation, with 2011 being ranked as the indicated more severe precipitation deficits in 2011 than driest water year in Southwest, Central, West Central, and Panhandle Oklahoma Climate Divisions and as the 11th driest indicated in table 1 of this report. The departure from normal year in the Northeast Climate Division, with precipitation precipitation (fig. B8 ) indicates the statewide distribution amounts ranging from 43 to 76 percent of long-term annual of precipitation deficits in water year 2011, as compared to median amounts for the period 1925–2011 (table 1). Statewide the 1971–2000 period. precipitation in water year 2011 was the second smallest in the 87 years of record from 1925–2011, with 60 percent of the long-term median annual precipitation falling in the State. Climate Division 1 Panhandle Only one year in the 1925–2011 period was drier—water For Climate Division 1 Panhandle in far northwestern year 1956, which had 56 percent of the long-term median precipitation. Oklahoma (fig. 7), water year 2011 was the driest in 87 years Climatic variables in Oklahoma are, in part, measured by of record from 1925–2011, having received an average of the Oklahoma Mesonet, a statewide network of 115 automated 11.09 in. of precipitation (table 1). That precipitation amount stations covering Oklahoma that records precipitation and was 56 percent of the long-term median annual precipitation, a other climatic data at 5-minute intervals. At least one Mesonet deficit of 8.75 in. (table 1).

1 PANHANDLE 2 3 NORTH CENTRAL NORTHEAST EXPLANATION 5 Climate Division number 4 O K L AHO MA CENTRAL and name WEST 6 CENTRAL 5 EAST CENTRAL 0 50 100 200 MILES CENTRAL

0 100 200 KILOMETERS 7 SOUTHWEST 8 9

Albers Equal Area Conic Projection SOUTH SOUTH- CENTRAL EAST Modified from Oklahoma Climatological Survey (2000)

Figure 7. National Weather Service Climate Divisions in Oklahoma. Precipitation by Climate Division 15

(G. McManus, Oklahoma Climatological Survey, written commun., 2012; “normal” rainfall is defined as mean annual precipitation from calendar years 1971–2000 in this figure)

Figure 8. Oklahoma (A) percent of normal rainfall, water year 2011, (B) departure from normal rainfall, water year 2011.

Figure 8. Percentage of normal precipitation, A, and departure from normal precipitation, B, for Oklahoma, water year 2011. 16 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

Climate Division 2 North Central Climate Division 7 Southwest

For Climate Division 2 North Central in north-central For Climate Division 7 Southwest in southwestern Oklahoma (fig. 7), water year 2011 was the fourth driest Oklahoma (fig. 7), water year 2011 was the driest in the in 87 years of record from 1925–2011, with 17.96 in. of 87 years of record from 1925–2011, receiving an average of precipitation falling, representing 62 percent of the long-term 12.05 in. of precipitation. The precipitation amount for water median annual precipitation, a deficit of 10.83 in. (table 1). year 2011 in Climate Division 7 Southwest was 43 percent Water year 1956 was the driest year recorded for Climate of the long-term median annual precipitation, a deficit of Division 2 North Central, with 15.10 in. of precipitation, 15.83 in. (table 1). 52 percent of the long-term median annual precipitation, and a deficit of 13.69 in. (table 1). Climate Division 8 South Central

Climate Division 3 Northeast For Climate Division 8 South Central in south-central Oklahoma (fig. 7), water year 2011 was the second driest For Climate Division 3 Northeast in northeastern in the 87 years of record from 1925–2011, having received Oklahoma (fig. 7), water year 2011 was the 11th driest in 18.86 in. of precipitation, which was 50 percent of the long- 87 years of record from 1925–2011, having received 30.17 in. term median annual precipitation, a deficit of 18.61 in. (table of precipitation, 76 percent of the long-term median annual 1). Water year 1956 was the driest year recorded for Climate precipitation, and a deficit of 9.79 in. (table 1). Water year 1956 Division 8 South Central, receiving an average of 16.46 in. of was the driest year recorded for Climate Division 3 Northeast, precipitation, which was 44 percent of the long-term median having received 22.90 in. of precipitation, 57 percent of annual precipitation, a deficit of 21.01 in. (table 1). the long-term median annual precipitation, and a deficit of 17.06 in. (table 1). Climate Division 9 Southeast

Climate Division 4 West Central For Climate Division 9 Southeast in southeastern Oklahoma (fig. 7), water year 2011 was the fourth driest in the For Climate Division 4 West Central in west-central 87 years of record from 1925–2011, receiving an average of Oklahoma (fig. 7), water year 2011 was the driest in 87 years 31.51 in. of precipitation, which was 65 percent of the long- of record from 1925–2011, having received an average of term median annual precipitation, a deficit of 16.62 in. (table 12.65 in. of precipitation (table 1). The precipitation amount 1). Water year 1956 was the driest year recorded for Climate for water year 2011 in Climate Division 4 West Central was Division 9 Southeast, having received an average of 25.10 in. 48 percent of the long-term median annual precipitation, of precipitation, which was 52 percent of the long-term representing a deficit of 13.74 in. (table 1). median annual precipitation, a deficit of 23.03 in. (table 1).

Climate Division 5 Central Streamflow of Long-Term Stations For Climate Division 5 Central in central Oklahoma (fig. 7), water year 2011 was the driest in 87 years of record Twelve long-term streamflow-gaging stations with from 1925–2011, having received an average of 19.59 in. of periods of record ranging from 67 to 83 years were selected precipitation. The precipitation amount for water year 2011 in to show how streamflow deficits varied by region (fig. 9, Climate Division 5 Central was 57 percent of the long-term table 2). Two graphs are presented for each long-term station median annual precipitation, a deficit of 14.74 in. (table 1). (figs. 10–21). The first graphA ( ) for each station is similar to the statewide runoff graph in figure 4. The median annual Climate Division 6 East Central streamflow (U.S. Geological Survey, 2012b) for each water year of the period of record is plotted as a departure from the For Climate Division 6 East Central in east-central long-term median annual streamflow (blue line), and a 5-year Oklahoma (fig. 7), water year 2011 was the second driest in weighted-average streamflow is plotted as a red line (allA the 87 years of record from 1925–2011, having received an graphs, figs. 10–21). Wetter-than-normal years plot above average of 26.08 in. of precipitation, 60 percent of the long- the median line and drier-than-normal years plot below the term median annual precipitation, and a deficit of 17.25 in. median line. Water year 2011 can be compared to dry years (table 1). Water year 1956 was the driest year recorded for from the four previous major hydrologic droughts in the 20th Climate Division 6 East Central, having received 23.86 in. century by comparing the magnitude of the deviations from of precipitation, 55 percent of the long-term median annual the median value. The second graph on figures 10–21 precipitation, and a deficit of 19.47 in. (table 1). shows comparisons of daily mean streamflow from water Streamflow of Long-Term Stations 17 38 ˚ 36 ˚ 34 ˚

94 ˚

I R U O S S I M Illinois River near Tahlequah

Verdigris River Red River at Texas Arthur City, 96 ˚ at Calvin 96 ˚ Canadian River Blue River near Blue Cimarron River near Ripley North Canadian River near Wetumka River Red River near Gainesville, Texas Washita River near Dickson Salt Fork Arkansas River at Tonkawa 98 ˚ Chikaskia River near Blackwell 98 ˚ Cimarron River near Waynoka Salt Fork Red 100 ˚ River at Mangum 100 ˚ 102 ˚ 102 ˚ Selected long-term streamflow-gaging stations in Oklahoma and appendix photograph locations.

36 ˚ 34 ˚ Figure 9. 18 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

Table 2. Summary of streamflow conditions at selected long-term streamflow-gaging stations in Oklahoma comparing the median of mean annual streamflow (measure of “normal” streamflow) with average annual streamflow during periods of previously documented hydrologic droughts (1929–41, 1952–56, 1961–72, 1976–81) and the recent (2011) hydrologic drought period.

[mi2, square miles; N, nonregulated; R, regulated; WY, water year; ft3/s, cubic feet per second; rank, rank of driest year of drought period compared to period of record; avg, average; SW, statewide]

Continuous Contributing Long-term Type of period of Site Station drainage Years of annual Station name record record number number area record median (N/R) (complete (mi2) (ft3/s) WY)

SW Statewide1 11925–2011 87

1 07151000 Salt Fork Arkansas River at Tonkawa, Okla. 4,520 R 1942–2011 70 812

2 07152000 Chikaskia River near Blackwell, Okla. 1,859 N 1937–2011 75 499

3 07158000 Cimarron River near Waynoka, Okla. 8,504 N 1938–2011 74 223

4 07161450 Cimarron River near Ripley, Okla.2 13,053 N 1940–2011 72 1,347

5 07196500 Illinois River near Tahlequah, Okla. 959 N 1936–2011 76 950

6 07231500 Canadian River at Calvin, Okla. 23,151 N,R 1939–42, 71 1,439 1945–2011 7 07242000 North Canadian River near Wetumka, Okla. 9,391 R 1938–2011 74 692

8 07300500 Salt Fork Red River at Mangum, Okla. 1,357 N 1938–2011 74 67.7

9 07316000 Red River near Gainesville, Texas 24,846 N,R 1937–2011 75 2,508

10 07331000 Washita River near Dickson, Okla. 7,202 N,R 1929–2011 83 1,723

11 07332500 Blue River near Blue, Okla. 476 N 1937–2011 75 253

12 07335500 Red River at Arthur City, Texas 38,595 R 1945–2011 67 6,909 Streamflow of Long-Term Stations 19

[mi2, square miles; N, nonregulated; R, regulated; WY, water year; ft3/s, cubic feet per second; rank, rank of driest year of drought period compared to period of record; avg, average; SW, statewide]

Hydrologic drought periods 31929–41 31952–56 31961–72 31976–81 2011 Lowest year/rank Lowest year/rank Lowest year/rank Lowest year/rank Long-term Long-term Long-term Long-term Rank long- Avg median- Avg median- Avg median- Avg median- Avg term Site annual annual annual annual annual annual annual annual annual median- num- flow streamflow streamflow streamflow streamflow annual ber (ft3/s) flow (ft3/s) flow (ft3/s) flow (ft3/s) flow (ft3/s) streamflow (percent) (percent) (percent) (percent) (percent) SW 1940 3 1956 1 1964 4 1981 12 16

1 NA 1954 1 1964 3 1981 14 4 95.5 12 137 17 280 34 147 18 2 41940 2 1954 1 1966 4 1981 8 5 76.6 15 71.0 14 97.6 20 152 30 102 20 3 41939 30 1956 6 1971 5 1977 21 1 174 78 53.6 24 46.7 21 134 60 31.9 14 4 41940 4 1953 1 1971 2 1981 12 5 307 23 235 17 294 22 455 34 312 23 5 41940 6 1954 1 1964 3 1981 5 63 279 29 193 20 239 25 275 29 1,333 140 6 41940 9 1956 7 1966 3 1981 1 4 478 33 393 27 217 15 184 13 237 16 7 41940 2 1956 1 1963 3 1981 5 9 157 23 156 23 166 24 178 26 215 31 8 41940 1 1952 5 1971 3 1981 6 2 12.3 18 17.5 26 12.5 18 22.7 34 12.4 18 9 41939 6 1953 3 1964 4 1983 13 1 1,010 40 651 26 654 26 1,274 51 315 13 10 41939 4 1956 6 1964 2 1981 8 1 391 23 440 26 340 20 495 29 316 18 11 41939 2 1956 1 1964 10 1980 5 4 42.9 17 30.8 12 114 45 77.7 31 69.8 28 12 NA 1952 10 1964 3 1980 4 2 4,182 61 2,754 40 2,953 43 2,008 29 1Ranks from U.S. Geological Survey (2012a). 2Includes streamflow record 1940–87 from nearby station 07161000, Cimarron River at Perkins, Okla. 3Documented drought periods are modified from Tortorelli and others (1991). 4Station records do not span entire drought period. 20 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma year 2011 (red line) (U.S. Geological Survey, 2012b) to the years of record from 1938–2011, with 14 percent of the long- long-term daily mean streamflow (blue line) (U.S. Geological term median annual streamflow being recorded (table 2). Survey, 2012b) and provides an indication of how the During the drought of water year 2006, zero streamflow was streamflow deficits changed seasonally during water year recorded at this station only during early August (Tortorelli, 2011 compared to the period of record at that gage (all B 2008). Zero streamflow was recorded in water year 2011 graphs, figs 10–21). Statewide, water year 2011 had average- in late May and early June and from late June through annual streamflow that was the 16th smallest of the period September, with above-mean streamflow recorded in early 1925–2011, more than was recorded during the drought November 2010 (fig. 12) (U.S. Geological Survey, 2012c). periods of 1929–41, 1952–56, 1961–72, and 1976–81 (table 2). An average-annual streamflow ranking of only 16th smallest for this period, despite precipitation being ranked the 2d Cimarron River near Ripley smallest, may be related to the relatively large streamflow in Cimarron River near Ripley, Okla. (station number northeastern Oklahoma during water year 2011. 07161450, formerly named Cimarron River near Perkins, Okla., station number 0716000) is a streamflow-gaging Salt Fork Arkansas River at Tonkawa station in central Oklahoma (fig. 9). Water year 2011 was the fifth driest in the 72 years of record from 1940–2011 at Salt Fork Arkansas River at Tonkawa, Okla. (station that station, with 23 percent of long-term median annual number 07151000) is a streamflow-gaging station in north- streamflow being recorded (table 2). Water year 1953 was the central Oklahoma (fig 9). Water year 2011 was the fourth driest recorded year at the streamflow-gaging station, with driest in the 70 years of record at the station for the period 17 percent of long-term median annual streamflow being 1942–2011, with 18 percent of long-term median annual recorded. Zero streamflow was not recorded during water streamflow being recorded (table 2). Water year 1954 was year 2011, similar to the drought year of 2006, with above- the driest year at the station, with 12 percent of long-term mean streamflow being measured in late May 2011 (fig. 13; median annual streamflow being recorded. Zero streamflow Tortorelli, 2008). The smallest daily mean streamflow during was not recorded during water year 2011, similar to the the 2011 water year at this station was 16 ft3/s recorded on drought year 2006 (Tortorelli, 2008), with some streamflow September 2, 2011 (fig. 13) (U.S. Geological Survey, 2012c). near the long-term daily mean streamflow being recorded in November, May, August, and September (fig. 10). The smallest daily mean streamflow during water year 2011 was Illinois River near Tahlequah 4 cubic feet per second (ft3/s) recorded on September 13, 2011 Illinois River near Tahlequah, Okla. (station number (fig. 10) (U.S. Geological Survey, 2012c). 07196500) is a streamflow-gaging station in east-central Oklahoma (fig. 9). Water year 2011 was relatively wet, with Chikaskia River near Blackwell streamflow ranking 63d smallest in the 76 years of record from 1936–2011 at the station, with 140 percent of long-term Chikaskia River near Blackwell, Okla. (station number median annual streamflow being recorded (table 2). Water 07152000) is a streamflow-gaging station in north-central year 1954 was the driest year recorded at the station, with Oklahoma (fig. 9). Water year 2011 was the fifth driest 20 percent of long-term median annual streamflow being in the 75 years of record from 1937–2011 at that station, recorded. Zero streamflow was not recorded during water with 20 percent of long-term median annual streamflow year 2011, similar to the drought year of 2006, with some being recorded (table 2). Water year 1954 was the driest above-mean streamflow being recorded in late February year at the station, with 14 percent of long-term median and early March, late April, May, mid-August, and late annual streamflow being recorded. Zero streamflow was September of 2011 (fig. 14; Tortorelli, 2008). Large amounts not recorded during water year 2011 at the station, similar of precipitation produced substantial runoff in the watershed to the drought year of 2006 (Tortorelli, 2008), with some upstream from the station in April and May, contributing to above-median streamflow recorded in February, April, and the relatively large median annual streamflow at the site. The mid-September (fig. 11). The smallest daily mean streamflow smallest daily mean streamflow during the 2011 water year at during water year 2011 was 1.5 ft3/s recorded on September this station was 159 ft3/s recorded on September 15, 2011 (fig. 6, 2011 (fig. 11) (U.S. Geological Survey, 2012c). 14) (U.S. Geological Survey, 2012c).

Cimarron River near Waynoka Canadian River at Calvin

Cimarron River near Waynoka, Okla. (station number Canadian River at Calvin, Okla. (station number 07158000) is a streamflow-gaging station in northwestern 07231500) is a streamflow-gaging station in east-central Oklahoma (fig. 9). Water year 2011 was the driest in the 74 Oklahoma (fig. 9). Water year 2011 was the fourth driest in Streamflow of Long-Term Stations 21

A Hydrologic droughts: 1952–56 1961–72 1976–81 2011 4,000

, Salt Fork Arkansas River at Tonkawa, Okla. 07151000 3,500

l o w Regulated 1942–2011 f 3,000 EXPLANATION r e a m s t /s) 3 2,500 Annual departure Median annual streamflow 812 ft3/s a n u l o n d (ft 2,000 5-year weighted average e c s

m e d i a n 1,500 p e r

e t r o m f f 1,000 u r e u b i c 500 in c d e p a r t 0

A n u a l -500

-1,000 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

100,000 60,000 Salt Fork Arkansas River at Tonkawa, Okla. 07151000 40,000 30,000 20,000 EXPLANATION

10,000 Daily mean streamflow, water year 2011 /s) 3 6,000 Long-term daily mean streamflow, water years 1942–2011 (ft

d 4,000 Regulated 1942–2011

n 3,000 2,000 s e c o

e r 1,000 p 600

f e t 400

c 300 i

b 200 c u

i 100

w , 60 o 40 30

e a m f l 20 S t r 10 6 4 3 2

1 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month Data from U.S. Geological Survey (2012b)

Figure 10. Streamflow data for Salt Fork Arkansas River at Tonkawa, Oklahoma, water years 1942–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. 22 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 2,000

, in Chikaskia River near Blackwell, Okla. 07152000 Unregulated 1937–2011 l o w f 1,500 EXPLANATION r e a m s t /s)

3 Annual departure Median annual streamflow 499 ft3/s a n u l

o n d (ft 5-year weighted average 1,000 e c s m e d i a n p e r

e t r o m f f 500 u r e u b i c c

d e p a r t

A n u a l

-500 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

100,000 60,000 Chikaskia River near Blackwell, Okla. 07152000 40,000 30,000 EXPLANATION 20,000 Daily mean streamflow, water year 2011 10,000 Long-term daily mean streamflow, water years 1937–2011 /s) 3 6,000 Unregulated 1937–2011 (ft

d 4,000

n 3,000 2,000 s e c o

e r 1,000 p 600

f e t 400

c 300 i

b 200 c u

i 100

w , 60 o 40 30

e a m f l 20 S t r 10 6 4 3 2

1 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month Data from U.S. Geological Survey (2012b)

Figure 11. Streamflow data for Chikaskia River near Blackwell, Oklahoma, water years 1937–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. Streamflow of Long-Term Stations 23

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 1,000 Cimarron River near Waynoka, Okla. 07158000 ,

w Unregulated 1938–2011 o l f 750

m EXPLANATION a r e s t

Annual departure /s) l 3 t a 3

u Median annual streamflow 223 ft /s ( f 500

n d 5-year weighted average n a n

o n c a e i s d r 250 e m e p

t m e e r o f f

c i r e b

u 0 u r t c

a n p i d e

a -250 u n A n

-500 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

10,000 6,000 Cimarron River near Waynoka, Okla. 07158000 4,000 3,000 EXPLANATION 2,000 Daily mean streamflow, water year 2011 /s) 3 Long-term daily mean streamflow, water years 1938–2011

( f t 1,000

d Unregulated 1938–2011

n 600 400 s e c o 300 e r

p 200 f e t

c 100 i b 60 c u

n i

w , 30 o 20

e a m f l 10 S t r 6 4 3 Zero flow 2 Zero flow Zero flow 1 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct

Month Data from U.S. Geological Survey (2012b)

Figure 12. Streamflow data for Cimarron River near Waynoka, Oklahoma, water years 1938–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. 24 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 5,000

, Cimarron River near Ripley, Okla. 07161450 4,500 w Unregulated 1940–2011 o l f m

a EXPLANATION

r e 3,500 s t

Annual departure /s) l 3 t a 3 u

( f Median annual streamflow 1,347 ft /s

n d 5-year weighted average n a n

o 2,500 n c a e i s d r e m e p

t m

e 1,500 e r o f f

c i r e b u u r t c

a 500 n p i d e

l a u

n -500 A n

-1,500 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

100,000 60,000 Cimarron River near Ripley, Okla. 07161450 40,000 30,000 EXPLANATION 20,000 Daily mean streamflow, water year 2011

/s) Long-term daily mean streamflow, water years 1940–2011 3 10,000 ( f t

Unregulated 1940–2011

d 6,000 n 4,000 3,000 s e c o

e r 2,000 p

f e t 1,000 c i

b 600 c u 400 n i 300 w ,

o 200

e a m f l 100

S t r 60 40 30 20

10 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month Data from U.S. Geological Survey (2012b)

Figure 13. Streamflow data for Cimarron River near Ripley, Oklahoma, water years 1940–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. Streamflow of Long-Term Stations 25

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 2,000

, 1,750 Illinois River near Tahlequah, Okla. 07196500 EXPLANATION w o

l Unregulated 1936–2011 f 1,500 Annual departure m

a Median annual streamflow 950 ft3/s r e 1,250

s t 5-year weighted average

/s) l 3 t a u ( f 1,000 n d n a n

o n c 750 a e i s d r

e 500 m e p

t m e e

r o 250 f f

c i r e b u

u 0 r t c

a n p i -250 d e

l a

u -500 n

A n -750

-1,000 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

1,000,000 600,000 Illinois River near Tahlequah, Okla. 07196500 400,000 300,000 EXPLANATION 200,000 Daily mean streamflow, water year 2011 /s) 3 100,000 Long-term daily mean streamflow, water years 1936–2011 ( f t

d Unregulated 1936–2011

n 60,000 40,000 s e c o 30,000 e r

p 20,000

f e t 10,000 c i b 6,000 c u

i 4,000

3,000 w , o 2,000

e a m f l 1,000 S t r 600 400 300 200

100 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month Data from U.S. Geological Survey (2012b)

Figure 14. Streamflow data for Illinois River near Tahlequah, Oklahoma, water years 1936–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. 26 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma the 71 years of record from 1939–42 and 1945–2011, with Water year 2006 was the second driest year on record, with 16 percent of the long-term median annual streamflow being 23 percent of the long-term median annual streamflow being recorded (table 2). Water year 1981 was the driest year, with recorded at this station. Zero streamflow was not recorded 13 percent of the long-term median annual streamflow being during water year 2011 at this station, similar to the drought recorded. Zero streamflow was not recorded in water year year of 2006, but streamflow remained less than long-term 2011, with some brief periods of above-mean streamflow daily mean streamflow throughout water year 2011 (fig. 18) recorded in late April and late May at the station (fig. 15). Zero (Tortorelli, 2008). The smallest daily mean streamflow during streamflow was recorded during most of August in the drought the 2011 water year at the station was 24 ft3/s recorded on year of 2006 at this station (Tortorelli, 2008). The smallest September 1, 2011 (fig. 18) (U.S. Geological Survey, 2012c). daily mean streamflow at this station during the 2011 water year was 0.40 ft3/s recorded on September 6, 2011 (fig. 15) (U.S. Geological Survey, 2012c). Washita River near Dickson Washita River near Dickson, Okla. (station number North Canadian River near Wetumka 07331000) is a streamflow-gaging station in south-central Oklahoma (fig. 9). Water year 2011 was the driest in the North Canadian River near Wetumka, Okla. (station 83 years of record from 1929–2011, with 18 percent of the number 07242000) is a streamflow-gaging station in central long-term median annual streamflow being recorded (table Oklahoma (fig. 9). Water year 2011 was the ninth driest in the 2). Water year 1964 was the second driest year recorded at 74 years of record from 1938–2011, with 31 percent of the this station, with 20 percent of the long-term median annual long-term median annual streamflow being recorded (table streamflow being recorded. Zero streamflow was not recorded 2). Water year 1956 was the driest year at the station, with during water year 2011 at this station, similar to the drought 23 percent of the long-term median annual streamflow being year of 2006, with daily mean streamflow briefly equaling or recorded. Zero streamflow was not recorded during water year exceeding long-term daily mean streamflow in late May and 2011 at this station, similar to the drought year of 2006, with mid-August of 2011 (fig. 19) (Tortorelli, 2008). The smallest some periods of streamflow near or above the long-term daily daily mean streamflow during the 2011 water year was 1.0 mean streamflow being recorded in February, April and May ft3/s recorded at this station on August 8, 2011 (fig. 19) (U.S. (fig. 16; Tortorelli, 2008). The smallest daily mean streamflow Geological Survey, 2012c). during the 2011 water year was 34 ft3/s recorded at this station on August 6, 2011 (fig. 16) (U.S. Geological Survey, 2012c). Blue River near Blue Salt Fork Red River at Mangum Blue River near Blue, Okla. (station number 07332500) is a streamflow-gaging station in south-central Oklahoma Salt Fork Red River near Mangum, Okla. (station number (fig. 9). Water year 2011 was the fourth driest in the 75 years 07300500) is a streamflow-gaging station in southwestern of record from 1937–2011, with 28 percent of the long-term Oklahoma (fig. 9). Water year 2011 was the second driest in median annual streamflow being recorded (table 2). Water the 74 years of record from 1938–2011, with 18 percent of the year 1956 was the driest year recorded at the station, with long-term median annual streamflow being recorded (table 2). 12 percent of the long-term median annual streamflow being Water year 1940 was the driest year recorded at the station, recorded. Zero streamflow was not recorded during water year with 18 percent of the long-term median annual streamflow 2011 at the station, similar to the drought year of 2006, with being recorded. Zero streamflow was recorded in water year daily mean streamflow briefly equaling or exceeding long- 2011 during part of October 2010 and from mid-May through term daily mean streamflow in late December, late April, and September, with short periods of above-mean streamflow late May of 2011 (fig. 20) (Tortorelli, 2008). The smallest measured in October, November, and February (fig. 17) (U.S. daily mean streamflow during the 2011 water year at this Geological Survey, 2012c). In the drought year of 2006, zero station was 0.24 ft3/s recorded on August 29, 2011 (fig. 20) flow was recorded for a shorter period, from late June through (U.S. Geological Survey, 2012c). August at this station (Tortorelli, 2008). Red River at Arthur City, Texas Red River near Gainesville, Texas Red River at Arthur City, Tex. (station number 07335500) Red River near Gainesville, Tex., (station number is a streamflow-gaging station in southeastern Oklahoma (fig. 07316000), is a streamflow-gaging station in south-central 9). Water year 2011 was the second driest in the 67 years of Oklahoma (fig. 9). Water year 2011 was the driest in the record from 1945–2011, with 29 percent of the long-term 75 years of record from 1937–2011, with 13 percent of the median annual streamflow being recorded (table 2). Water long-term median annual streamflow being recorded (table 2). year 2006 was the driest year on record for this station, with Streamflow of Long-Term Stations 27

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 5,000 Canadian River at Calvin, Okla. 07231500

w , Unregulated 1939–64 Regulated 1965–2011

o 4,000 EXPLANATION e a m f l Annual departure /s) 3,000 3 Median annual streamflow 1,439 ft3/s 5-year weighted average 2,000

1,000

cubic feet per second (ft 0 n i

-1,000 Annual departure from median annual s t r

-2,000 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

1,000,000 600,000 400,000 Canadian River at Calvin, Okla. 07231500 200,000 EXPLANATION

/s) 100,000 3 60,000 ( f t 40,000 Daily mean streamflow, water year 2011 d n 20,000 Long-term daily mean streamflow, water years 1939–42, 1945–2011 10,000 Regulated 1965–2011 s e c o 6,000 e r 4,000 p 2,000 f e t 1,000 c i

b 600 400 c u

i 200

w , 100 o 60 40

e a m f l 20

S t r 10 6 4 2 1 0.6 0.4 0.2 0.1 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month Data from U.S. Geological Survey (2012b)

Figure 15. Streamflow data for Canadian River at Calvin, Oklahoma, water years 1939–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. 28 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 2,000 North Canadian River near Wetumka, Okla. 07242000 1,750 Regulated 1938–2011 w , o 1,500 EXPLANATION

e a m f l 1,250 Annual departure /s)

3 Median annual streamflow 692 ft3/s 1,000 5-year weighted average

750

500

250

0 cubic feet per second (ft n

i -250

-500

Annual departure from median annual s t r -750

-1,000 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

100,000 60,000 North Canadian River near Wetumka, Okla. 07242000 40,000 30,000 EXPLANATION 20,000 /s)

3 Daily mean streamflow, water year 2011 ( f t

Long-term daily mean streamflow, water years 1938–2011

d 10,000

n Regulated 1938–2011 6,000 s e c o 4,000

e r 3,000 p 2,000 f e t c i

b 1,000 c u

n 600 i

400 w ,

o 300 200 e a m f l

S t r 100 60 40 30 20

10 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month Data from U.S. Geological Survey (2012b)

Figure 16. Streamflow data for North Canadian River near Wetumka, Oklahoma, water years 1938–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. Streamflow of Long-Term Stations 29

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 250 Salt Fork Red River at Mangum, Okla. 07300500 Unregulated 1938–2011 w ,

o 200 EXPLANATION

e a m f l Annual departure

/s) 150 3

3 Median annual streamflow 67.7 ft /s 5-year weighted average

100

cubic feet per second (ft 0 i n

-50 Annual departure from median annual s t r

-100 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year B

10,000 6,000 Salt Fork Red River at Mangum, Okla. 07300500 4,000 3,000 EXPLANATION 2,000 Daily mean streamflow, water year 2011 /s)

3 Long-term daily mean streamflow, water years 1938–2011

( f t 1,000

Unregulated 1938–2011 d

n 600 400 s e c o 300 e r

p 200 f e t

c 100 i b 60 c u

i 40 30 w , o 20

e a m f l 10 S t r 6 Zero flow Zero flow 4 3 2 Zero flow

1 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct

Data from U.S. Geological Survey (2012b) Month

Figure 17. Streamflow data for Salt Fork Red River at Mangum, Oklahoma, water years 1938–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. 30 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 10,000 w ,

o Red River near Gainesville, Texas 07316000 Unregulated 1937–1944 8,000 EXPLANATION

e a m f l Regulated 1945–2011

/s) Annual departure 3 Median annual streamflow 2,508 ft3/s 6,000 5-year weighted average

4,000

2,000 cubic feet per second (ft n i 0

Annual departure from median annual s t r -2,000

-4,000 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

100,000 60,000 Red River near Gainesville, Texas 07316000 40,000 30,000 EXPLANATION 20,000 Daily mean streamflow, water year 2011 /s)

3 Long-term daily mean streamflow, water years 1937–2011 ( f t 10,000 Regulated 1945–2011 d n 6,000 4,000 s e c o 3,000 e r p 2,000 f e t c

i 1,000 b

c u 600

n i 400

w , 300 o 200 e a m f l 100 S t r 60 40 30 20

10 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month Data from U.S. Geological Survey (2012b)

Figure 18. Streamflow data for Red River near Gainesville, Texas, water years 1937–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. Streamflow of Long-Term Stations 31

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 6,000 Washita River near Dickson, Okla. 07331000 w ,

o 5,000 Unregulated 1929–1960 Regulated 1962–2011 e a m f l 4,000 EXPLANATION /s)

3 Annual departure Median annual streamflow 1,723 ft3/s 3,000 5-year weighted average

2,000

1,000 cubic feet per second (ft n i 0

-1,000 Annual departure from median annual s t r

-2,000 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

100,000 60,000 Washita River near Dickson, Okla. 07331000 40,000 30,000 EXPLANATION 20,000 Daily mean streamflow, water year 2011 10,000 Long-term daily mean streamflow, water years 1929–2011 /s) 3 6,000 Regulated 1962–2011 ( f t

4,000

d 3,000 n 2,000 s e c o 1,000 e r p 600 400 f e t 300 c i 200 b c u

n 100 i

60 w ,

o 40 30 20 e a m f l

S t r 10 6 4 3 2

1 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month Data from U.S. Geological Survey (2012b)

Figure 19. Streamflow data for Washita River near Dickson, Oklahoma, water years 1929–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. 32 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 1,000 Blue River near Blue, Okla. 07332500 EXPLANATION w , Unregulated 1937–2011 o 750 Annual departure Median annual streamflow 253 ft3/s e a m f l 5-year weighted average /s) 3 500

250

0 cubic feet per second (ft n i

-250 Annual departure from median annual s t r

-500 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

100,000 60,000 40,000 Blue River near Blue, Okla. 07332500 20,000 EXPLANATION 10,000 Daily mean streamflow, water year 2011 6,000 4,000 Long-term daily mean streamflow, water years 1937–2011 /s) 3 Unregulated 1937–2011

( f t 2,000

n 1,000 600

s e c o 400

e r

p 200 100 f e t 60 c i

b 40 c u

20 n i 10 w ,

o 6 4

e a m f l 2

S t r 1 0.6 0.4 0.2 0.1 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month Data from U.S. Geological Survey (2012b)

Figure 20. Streamflow data for Blue River near Blue, Oklahoma, water years 1937–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. Groundwater Levels at SelectedLong-Term Stations 33

26 percent of the long-term median annual streamflow being percentage of conservation storage for the entire water year recorded. Zero streamflow was not recorded during water 2011 (table 3). year 2011 at the station, similar to the drought year of 2006, The condition of farm ponds across Oklahoma was more with daily mean streamflow briefly equaling or exceeding drastically affected than the major reservoirs with hundreds of long-term daily mean streamflow in early February and early farm ponds across Oklahoma having completely dried up by and late May of 2011 (fig. 21) (Tortorelli, 2008). The smallest July 2011, which, along with lack of local hay and high feed daily mean streamflow during the 2011 water year at this prices caused widespread sell-offs of State cattle herds (Hayes, station was 207 ft3/s recorded on September 26, 2011 (fig. 21) 2011a). In addition to low lake levels and streamflow affecting (U.S. Geological Survey, 2012c). water supplies and recreational tourism, hot, stagnant, nutrient-enriched water caused widespread blooms of blue- green algae (Cyanophyta) in many reservoirs throughout Effects of Low Streamflows the State, which may have caused some illnesses, impaired the clarity of water, and caused economic losses to local businesses (Cross, 2011; Lawrence, 2012; Sewell, 2011). Hydrologic drought is associated with the effects of periods of precipitation deficits on streamflow, lake and reservoir levels, and groundwater levels. Although Hydroelectric Power Generation all droughts start with precipitation deficits (fig. 1), hydrologists are more concerned with how these deficits Hydroelectric power generation in Oklahoma was affect the surface-water and groundwater components of substantially reduced at many reservoirs during calendar year the hydrologic system. Hydrologic droughts commonly lag 2011 because of a reduction in available streamflow, as a result meteorological and agricultural droughts. During hydrologic of the hydrologic drought. Calendar year 2011 hydroelectric droughts, precipitation deficiencies take longer to show power generation at stations in Oklahoma ranged from 24 up in components of the hydrologic system. For example, to 112 percent of the calendar year 2010 power generation, precipitation deficits may result in a rapid depletion of soil with the sum of hydroelectric power generation at nine moisture that has an immediate effect on agriculture (Jackson, reservoirs declining by 42 percent in 2011 compared to 2010 2006a), but the effect of drought on reservoir levels may (table 4). Reduced hydropower generation during droughts not affect water supply, hydroelectric power production, or in Oklahoma requires substitution of electrical generation recreational uses for several months. Water in the hydrologic capacity by combustion of fossil fuels such as coal and natural storage systems of rivers and reservoirs commonly has gas (Renewable Energy Policy Network for the 21st century, multiple and competing purposes including flood control, 2012). Greater power generation with coal and natural gas, irrigation, recreation, navigation, hydropower, and wildlife typically costs more than hydropower generation and creates habitat. Competition for this water escalates during drought emissions of additional greenhouse gases and solid wastes and conflicts between water users can increase substantially associated with fossil fuel combustion (Renewable Energy (National Drought Mitigation Center, 2012). Policy Network for the 21st Century, 2012).

Conditions at Major Reservoirs Groundwater Levels at Selected The hydrologic drought of water year 2011 substantially affected reservoirs in the State (table 3, fig. 22) (Oklahoma Long-Term Stations Water Resources Board, 2010a–d, 2011a–j; U.S. Army Corps of Engineers, 2012). On September 29, 2011, the day A long-term recording groundwater well that is in before the end of the water year 2011, the statewide total hydraulic connection with a stream illustrates the effect the conservation storage was 83.3 percent (table 3), which was water year 2011 drought had on groundwater levels in south- the lowest statewide conservation storage recorded in water central Oklahoma. The daily mean water level recorded in year 2011 and was slightly less than the conservation storage a well completed to 396 feet (ft) below land surface in the of 86.3 percent available at the end of water year 2006 Arbuckle-Simpson aquifer near Fittstown, Okla., was several (Tortorelli, 2008). The wettest day (having the greatest amount feet above the long-term daily mean water level in September of conservation storage) of water year 2011 was April 14, and much of October 2010 but had decreased to about 11 ft 2011, when the statewide total conservation storage was the lower than long-term daily mean water levels by the end of highest (100 percent; table 3). The northeastern region of the water year 2011 (fig. 23A). A well completed to 122 ft below State consistently had the highest percentage of conservation land surface in the Arbuckle-Simpson aquifer in an adjoining storage, whereas the southwestern region of the State county (Johnston) had similar changes in groundwater levels consistently had the lowest percentage of conservation storage during water year 2011, ending the year at about 5 ft lower (table 3). Lake Altus at Lugert (map identifier 20, fig. 22) in than long-term daily-mean water levels measured at that well the southwestern region was the reservoir with the lowest (fig. 24A). A well completed to 386 ft below land surface in 34 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

A Hydrologic droughts: 1929–41 1952–56 1961–72 1976–81 2011 20,000 Red River at Arthur City, Texas 07335500 EXPLANATION w ,

o Regulated 1945–2011 Annual departure 15,000 Median annual streamflow 6,909 ft3/s e a m f l 5-year weighted average /s) 3 10,000

5,000

0 cubic feet per second (ft n i

-5,000 Annual departure from median annual s t r

-10,000 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water year

1,000,000 600,000 Red River at Arthur City, Texas 07335500 400,000 EXPLANATION 300,000 200,000 Daily mean streamflow, water year 2011 Long-term daily mean streamflow, water years 1945–2011 /s)

3 100,000 Regulated 1945–2011 ( f t

d 60,000 n 40,000 30,000 s e c o 20,000 e r p

10,000 f e t c i 6,000 b

c u 4,000

n 3,000 i

w , 2,000 o

1,000 e a m f l 600 S t r 400 300 200

100 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct

Month

Data from U.S. Geological Survey (2012b) Figure 21. Streamflow data for Red River at Arthur City, Texas, water years 1945–2011. A, Annual departure from long-term median annual streamflow, and B, Comparison between daily mean streamflow, water year 2011, and long-term daily mean streamflow. Groundwater Levels at SelectedLong-Term Stations 35

Table 3. Storage in selected major Oklahoma lakes and reservoirs on September 29, 2011, by National Weather Service Climate Division, and comparison with April 14, 2011, storage.

[Shading indicates reservoir storage below 80 percent of total conservation storage; WY, water year; Regional totals and averages are based on conservation storage in acre-feet for the lakes and reservoirs in each climate division; daily storage numbers above conservation storage amounts are rounded down to 100 percent, as storage above conservation storage is considered to be in the flood pool of a reservoir; *, indicates seasonal pool operation; actual storage figures/ percents may vary]

Site Conservation 09/29/11 Percent of conservation storage Climate division number storage storage WY end WY driest WY wettest lake or reservoir (fig. 22) (acre-feet) (acre-feet) 09/29/11 09/01/11 04/14/11 2 North Central 1 Fort Supply 12,221 7,958 65.1 73.1 100 2 Kaw* 437,120 374,569 85.7 86.9 92.1 Regional totals/averages 449,341 382,527 85.1 86.5 92.4 3 Northeast 3 Birch 18,221 13,611 74.7 81.0 96.3 4 Copan 34,647 30,852 89.0 94.7 100 5 Fort Gibson 365,200 353,045 96.7 98.0 100 6 Grand 1,478,860 1,495,291 100 100 100 7 Hudson 200,185 207,372 100 100 100 8 Hulah 22,565 18,395 81.5 91.5 100 9 Keystone 449,961 385,748 85.7 86.2 91.1 10 Oologah 549,300 496,410 90.4 93.3 100 11 Stiatook 323,607 220,149 68.0 62.9 84.2 Regional totals/averages 3,442,546 3,220,873 93.6 94.2 99.8 4 West Central 12 Canton 109,742 68,740 62.6 64.9 100 13 Foss 183,092 144,095 78.7 80.9 92.6 Regional totals/averages 292,834 212,835 72.7 74.9 96.1 5 Central 14 Arcadia 29,546 23,024 77.9 80.1 92.6 15 Heyburn 5,325 4,241 79.6 80.9 100 16 Thunderbird 119,600 91,350 76.4 79.6 84.7 Regional totals/averages 154,471 118,615 76.8 79.8 87.0 6 East Central 17 Eufaula* 2,253,993 1,806,690 80.2 83.0 81.9 18 Tenkiller 654,246 594,260 90.8 91.5 96.3 Regional totals/averages 2,908,239 2,400,950 82.6 84.9 85.2 7 Southwest 19 Fort Cobb 74,030 59,862 80.9 84.4 99.5 20 Altus 128,919 23,232 18.0 18.9 50.8 21 Tom Steed 97,520 58,046 59.5 63.2 82.0 Regional totals/averages 300,469 141,140 47.0 49.4 72.9 8 South Central 22 Arbuckle 72,400 58,844 81.3 84.7 96.5 23 McGee Creek 113,959 97,870 85.9 91.6 93.8 24 Texoma* 2,692,553 2,042,069 75.8 78.2 84.8 25 Waurika* 191,406 147,208 76.9 79.3 93.9 Regional totals/averages 3,070,318 2,345,991 76.4 75.7 86.0 9 Southeast 26 Broken Bow* 919,485 814,390 88.6 88.6 88.7 27 Hugo* 171,009 112,735 65.9 73.9 88.9 28 Pine Creek* 38,608 20,352 52.7 62.0 99.3 29 Sardis 274,192 246,249 89.8 92.2 94.2 30 Wister 49,441 37,364 75.6 83.0 100 Regional totals/averages 1,452,735 1,231,090 84.7 86.7 90.8 State totals 12,070,953 10,054,021 83.3 85.1 100 Resevoirs below 80 percent storage 15 10 1 36 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma ° ° ° 8 6 4 3 3 3

4 9 I R U O S S I M S A S N A K R A 2 6 3 0 6 N

e 1 8 osho River 2 8 7 2 9 is 5 erdigr 1 7 V R iver 2 7 1 0 4 ° ° 6 6 2 3 9 9 3 r e

8 iv 1 R 1 1 5 as

ans 9 rk A 2 4 r e v i 2 R 2 an

1 6 anadi C 1 4 S

r A e v

° r e i 8 R 9 iv T E X 5 R ° 8 2 9 a t ron ar hi im as 2

S C W 9 1 1 S A r N e r v i e v R i K A 1 R 2 an d

3 r e e

1 v i R anadi d R C Re

k 0 or 2 F 1 h h t t or o r ° N 0 N 0 1 ° 0 0 1 S E L I M 0 0 1 S R E T E M N O L O I K T I 0 A 0 1 N ° A 0 2 L 5 0 1 P E X 0 5 ° 80 90 100 2 5 0 – – – 2 1 <50 51–70 71 81 91 5 O 2 D A Conservation storage as of September 29, 2011, in percent Numbers at reservoir at Numbers locations correspond to table 3 Protection Environmental U.S. from Rivers Agency River Reach File version 1 Albers Equal-Area projection North American Datum of 1983 0 0 R O L

Locations of selected major Oklahoma lakes and reservoirs percentage conservation storage as September 29, 2011. O

O C I X E M W E C N

° ° 6 4 3 3 Figure 22. Groundwater Levels at SelectedLong-Term Stations 37

Table 4. Comparison of hydroelectric power generation at selected Oklahoma hydroelectric plants between calendar years 2010 and 2011.

[GWh, Gigawatt-hour; CY, calendar year]

Calendar year Calendar year 2011 Site number Lake hydroelectric Climate division 2010 power (fig. 22) generation project Power Percent of (GWh) (GWh) CY 2010 power

2 Kaw1 2 North Central 110 26 24

5 Fort Gibson2 3 Northeast 252 158 63

6 Grand (Pensacola)3 3 Northeast 528 321 61

7 Hudson (RS Kerr)3 3 Northeast 278 171 62

7 Salina3, 4 3 Northeast 233 229 98

9 Keystone2 3 Northeast 296 68 23

17 Eufaula2 6 East Central 328 96 29

18 Tenkiller2 6 East Central 120 106 88

26 Broken Bow2 9 Southeast 108 121 112

Sum 2,253 1,297 58

1Data from J. Rogers (Oklahoma Municipal Power Authority, written commun., 2012). 2Data from A. Corker (Southwestern Power Administration, written commun., 2012). 3Data from D. Townsend and W. Potter (Grand River Dam Authority, written commun., 2012). 4Salina Pumped Storage Project, Chimney Rock Reservoir. Water used on the Salina Creek Arm of Lake Hudson, classified as offstream project.

the High Plains aquifer in the panhandle (fig. 25A) did not of low-permeability caliche. Materials in that aquifer tend to have responses to wet and dry periods during the year, but the have relatively small permeability. Precipitation and recharge long-term downward trend in groundwater levels recorded amounts also tend to be much less in the panhandle than in since the mid-1960s continued. the rest of the State and water tables in the High Plains aquifer The Arbuckle-Simpson aquifer is karstic, consisting generally are several hundred feet below land surface (Luckey of highly permeable limestone and dolomite rocks with and others, 2000; Wood, 2000). All of those factors combine relatively shallow water tables and good hydraulic connection to attenuate short-term water-level changes in wet and dry to local streams, which contribute to relatively rapid periods in the High Plains aquifer. Long-term declines in responses to precipitation events and drought (Christenson groundwater levels in the High Plains aquifer are well-known, and others, 2011). The High Plains aquifer of northwestern being caused by water withdrawals that exceed recharge in Oklahoma consists of layers of silty sands with some layers that relatively arid area (McGuire, 2011). 38 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

A 90 Groundwater well near Fittstown, Okla. 01N–06E–04 CAD 1 95 EXPLANATION

Daily mean water level, water year 2011 100 Long-term daily mean water level, water years 1981–2011

105

110

115

Missing Daily water level, in feet below land surface data 120

125 Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Month B

70 EXPLANATION

Continuously recorded water level, water years 2008–12 LOESS curve of measured water levels, water years 1959–2012 80 Measured water levels, water years 1959–2012

100

110

Water level, in feet below land surface 115

120

125 1958 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2013 Year

Data from U.S. Geological Survey (2012c) Figure 23. A, Daily-mean water levels, water year 2011; B, Long-term daily mean water levels and all water levels measured in a groundwater well near Fittstown, Oklahoma, water years 1958–2012. Groundwater Levels at SelectedLong-Term Stations 39

A 10 Groundwater well Johnston 31 01S–05E–31 CBD 14 EXPLANATION f a c e r Daily mean water level, water year 2011 s u Long-term mean daily water level, water years 2006–11 d 19 a n l w o e l

b 23 in f e t

, 27 l e v

w a t e r 31 y l a i D

40 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month B 5 EXPLANATION

LOESS curve of measured water levels, water years 2007–12 10 Continuously recorded water level, water years 2017–12

15 f a c e r s u

d a n l

w 20 o e l b in f e t

, 25 l e v

W a t e r 30

37.5 Sept Jan Apr July Oct Jan Apr July Oct Jan Apr July Oct Jan Apr July Oct Jan Apr July 2007 2008 2009 2010 2011 2012 Month and year

Data from U.S. Geological Survey (2012c) Figure 24. A, Daily-mean water levels, water year 2011; B, Long-term daily mean water levels; and continuously recorded water levels measured in a groundwater well in Johnston County, Oklahoma, water years 2006–11. 40 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

A 201 Groundwater well near Texhoma, Okla. 01N–12E–35 BDD1 206 f a c e r s u

d 211 a n l

w EXPLANATION o e l

b 217 Daily mean water level, water year 2011 Long-term mean daily water level water years 1979–97, 2010–11 in f e t

, 223 l e v

w a t e r 229 y l a i D

234

240 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Month B 180

190 f a c e r s u

a n 200 l w o e l b in f e t

210 , l e v

W a t e r 220 EXPLANATION

Continuously recorded water level, water years 2010–12 LOESS curve of measured water levels, water years 1956–2012 Measured water levels, water years 1956–2012 230

234 1956 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2013 Year

Data from U.S. Geological Survey (2012c)

Figure 25. A, Daily-mean water levels, water year 2011; B, Long-term daily-mean water levels; and continuously recorded water levels measured in a groundwater well near Texhoma, Oklahoma, water years 1956–2011. References 41

Summary how precipitation deficits in Oklahoma varied by region. The nine climate divisions in Oklahoma had precipitation in water Water year 2011 (October 1, 2010, through year 2011 ranging from 43 to 76 percent of normal annual September 30, 2011) was a year of hydrologic drought, precipitation, with the Climate Division 3 Northeast having receiving the 2d lowest amount of precipitation and having the closest to normal precipitation and the Climate Division the 16th lowest average annual streamflow and the 42d 7 Southwest having the greatest percentage of annual deficit. lowest statewide runoff for Oklahoma recorded for the period Water year 2011 was the second driest of the 1925–2011 1925–2011. The period of water years 1925–2011 was selected period; only the drought period of 1952–56 had a year with as the period of record to examine hydrologic drought in less precipitation. this report because before 1925 few continuous record Regional streamflow for water year 2011 indicated that streamflow-gaging stations existed and gaps existed where no streamflow conditions for the Arkansas-White-Red water streamflow-gaging stations were operated. In 2011, effects of resources region, the 26th lowest since 1930, were considered the drought became particularly severe during the summer, to be normal, despite the very dry conditions in the southern with the statewide average temperature of 89.1°F during July and southwestern parts of the region in Oklahoma. Twelve being the hottest month recorded for any State since 1895. long-term streamflow-gaging stations with periods of record Some effects of drought during water year 2011 included: ranging from 67 to 83 years were selected to show how 1. streamflow being nearly the smallest recorded for the streamflow deficits varied by region in the State. Statewide, period 1925–2011, particularly in western and southwest- water year 2011 had average annual streamflow that was the ern Oklahoma; 16th lowest, and statewide runoff that was the 42d lowest of the period 1925–2011, more than was measured in years 2. major reservoirs having only 83.3 percent of the statewide during the drought periods of 1929–41, 1952–56, 1961–72, conservation storage available at the end of the water and 1976–81. The hydrologic drought worsened from the year; northeast toward the southwest in Oklahoma, ranging from 3. calendar year 2011 hydroelectric power generation at streamflows 140 percent above normal in the northeast to stations in Oklahoma being about 58 percent of calendar 13 percent of normal in the southwest. The Red River near year 2010 power generation; Gainesville, Texas, long-term streamflow-gaging station in southwestern Oklahoma, had 13 percent of normal annual 4. groundwater levels in State aquifers having decreased; streamflow, the smallest long-term median annual streamflow 5. wildfires burning more than 300,000 acres and hundreds recorded at that station for the period 1937–2011. In the of structures; central part of the State, the North Canadian River near Wetumka, long-term streamflow-gaging station, had 31 6. voluntary and mandatory water-conservation measures percent of normal long-term median annual streamflow. and mandatory outdoor burn bans being enacted in some Conversely, in the northeastern part of the State, the Illinois parts of the State and states of emergency declared; River near Tahlequah, long-term streamflow-gaging station, 7. production of many major crops being less than half of had 140 percent of normal long-term median annual 2010 production; streamflow. Below-normal streamflow in much of the State resulted in major reservoirs containing 83.3 percent of the 8. hay and feed prices increasing and many farm ponds dry- statewide conservation storage at the end of the water year. ing up, forcing large sales of cattle and, thereby, decreasing cattle herds, which were down to the smallest numbers since 1968; References 9. recreational tourism on Oklahoma streams and lakes decreasing because of low water levels and blue-green Associated Press, 2011, Rainfall leads Governor Fallin to algae blooms; and amend Oklahoma burn ban: Tulsa World, September 10. above-normal mortality and poorer condition of many 26, 2011, accessed March 7, 2013, at http://www. species of aquatic and terrestrial wildlife being reported. tulsaworld.com/news/article.aspx?subjectid=12&articl eid=20110926_12_0_OKLAHO966810. The severity of the 2011 drought can be evaluated by comparing it with four previous major hydrologic droughts, Cable News Network, 2011a, Wildfires in Oklahoma, water years 1929–41, 1952–56, 1961–72, and 1976–81. Colorado force hundreds to evacuate: Cable News Network, Annual area-averaged precipitation totals for the nine National March 11, 2011. Weather Service Climate Divisions from water year 2011 were compared to precipitation totals for years in the four previous Cable News Network, 2011b, Wildfire forces evacuations in major hydrologic drought periods of the 20th century to show Oklahoma City: Cable News Network, August 30, 2011. 42 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

Christenson, Scott, Osborn, N.I., Neel, C.R., Faith, J.R., Hertneky, Dana, 2011, Severe drought leads to mandatory Blome, C.D., Puckette, James, and Pantea, M.P., 2011, water restrictions in Oklahoma City: KWTV, July 9, Hydrogeology and simulation of groundwater flow in the 2011, accessed July 20, 2012, at http://www.news9.com/ Arbuckle-Simpson aquifer, south-central Oklahoma: U.S. story/15053722/oklahoma-city-implements-water-rotation. Geological Survey Scientific Investigations Report 2011– 5029, 104 p. Hoyt, J.C., 1936, Droughts of 1930-34: U.S. Geological Survey Water Supply Paper 680, 106 p. Cleveland, W.S., and Devlin, S.J., 1988, Locally-weighted regression: An approach to regression analysis by local Hoyt, J.C., 1938, Drought of 1936: U.S. Geological Survey fitting: Journal of American Statistical Association, v. 83, p. Water Supply Paper 820, 62 p. 596–610. Jackson, Ron, 2006a, Farmers, ranchers feeling drain of Cross, Michael, 2011, Heat, drought pressure Oklahoma’s persistent drought conditions: The Oklahoman, July 11, water supplies: KOSU, accessed August 16, 2012, at http:// 2006, accessed March 6, 2008, at http://newsok.com/ www.npr.org/2011/08/16/139664424/heat-drought-pressure- farmers-ranchers-feeling-drain-of-persistent-drought- oklahomas-water-supplies. conditions/article/2000620.

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Oklahoma Water Resources Board, 2010b, Oklahoma Water Oklahoma Water Resources Board, 2011g, Oklahoma Water Resources Bulletin and summary of current conditions, Resources Bulletin and summary of current conditions, November 4, 2010: Oklahoma Water Resources Board, July 7, 2011: Oklahoma Water Resources Board, accessed accessed July 19, 2012, at http://www.owrb.ok.gov/supply/ July 19, 2012, at http://www.owrb.ok.gov/supply/drought/ drought/pdf_dro/2010/262_1104_2010.pdf. pdf_dro/2011/271_0707_2011.pdf. References 45

Oklahoma Water Resources Board, 2011h, Oklahoma Water Sewell, LaShauna, 2011, Blue-green algae still a problem at Resources Bulletin and summary of current conditions, some Oklahoma lakes: KWTV, July 28, 2011, accessed July August 4, 2011: Oklahoma Water Resources Board, 12, 2012, at http://www.newson6.com/story/15165513/blue- accessed July 19, 2012, at http://www.owrb.ok.gov/supply/ green-algae-stil-a-problem-at-some-oklahoma-lakes. drought/pdf_dro/2011/272_0804_2011.pdf. Tortorelli, R.L., 2008, Hydrologic drought of water year 2006 Oklahoma Water Resources Board, 2011i, Oklahoma Water compared with four major drought periods of the 20th Resources Bulletin and summary of current conditions, century in Oklahoma: U.S. Geological Survey Scientific September 1, 2011: Oklahoma Water Resources Board, Investigations Report 2008–5199, 46 p. accessed July 19, 2012, at http://www.owrb.ok.gov/supply/ drought/pdf_dro/2011/273_0901_2011.pdf. Tortorelli, R.L., Cooter, E.J., and Schuelein, J.W., 1991, Oklahoma Water Resources Board, 2011j, Oklahoma Water Oklahoma – Floods and droughts, in U.S. Geological Resources Bulletin and summary of current conditions, Survey, National water summary 1988–1989 – Hydrologic September 29, 2011: Oklahoma Water Resources Board, events and floods and droughts: U.S. Geological Survey accessed July 19, 2012, at http://www.owrb.ok.gov/supply/ Water-Supply Paper 2375, p. 451–458. drought/pdf_dro/2011/274_0929_2011.pdf. U.S. Army Corps of Engineers, 2012, Daily report of reservoir Olafson, Steve, 2011, Wildfires cause evacuations in two conditions—Lake data, Arkansas River Basin, Tulsa Oklahoma towns: WHTC, accessed March 7, 2013, at District Corps of Engineers: U.S. Army Corps of Engineers, http://whtc.com/news/articles/2011/mar/24/wildfires-cause- accessed July 23, 2012, at http://www.swt-wc.usace.army. evacuations-in-two-oklahoma-towns/. mil/old_resvrept.htm. Palmer, W.C., 1965, Meteorological drought: U.S. Weather U. S. Drought Monitor, 2011, U.S. Drought Monitor: National Bureau, Research Paper no. 45, 64 p. Drought Mitigation Center, accessed May 15, 2012, at Ray, Brandon, 2011, Drought has been severe on deer: Field http://droughtmonitor.unl.edu. and Stream, September 9, 2011, accessed July 12, 2012 at U.S. Geological Survey, 2012a, Computed runoff in http://www.fieldandstream.com/blogs/south-central-rut- report/2011/09/ray-drought-has-been-severe-deer. hydrologic units: U.S. Geological Survey, accessed July 19, 2012, at http://waterwatch.usgs.gov/new/index. Renewable Energy Policy Network for the 21st Century, 2012, php?dt=mv01d&plot_tp=nwc&st=xus&yr=2011&map_ Renewables 2012, global status report: Renewable Energy dt=2011&m=romap3&w=map. Policy Network for the 21st Century, Paris, France, 172 p., accessed March 27, 2013, at http://www.map.ren21.net/ U.S. Geological Survey, 2012b, USGS surface-water data for GSR/GSR2012.pdf. the Nation: U.S. Geological Survey, accessed July 18, 2012, at http://waterdata.usgs.gov/nwis/sw. Richter, Marice, 2011, Wildfires again rage through Texas and Oklahoma: Thomson Reuters, September 1, 2011, at U.S. Geological Survey, 2012c, Water-resources data for the http://www.reuters.com/article/2011/09/01/us-wildfires- United States, water year 2011: U.S. Geological Survey, idUSTRE77U7II20110901. accessed July 12, 2012, at http://wdr.water.usgs.gov/ Schoeling, Doug, 2011, 2011 August roadside quail survey wy2011/search.jsp. summary: Oklahoma Department of Wildlife Conservation, U.S. Geological Survey, 2012d, Table of computed runoff, accessed July 20, 2012, at http://www.wildlifedepartment. by water-year, for Oklahoma: U.S. Geological Survey, com/hunting/quail/augquail2011.pdf. accessed July 19, 2012, at http://waterwatch.usgs.gov/index. Severson, Kim, and Johnson, Kirk, 2011, Drought php?r=ok&id=statesum. spreads pain from Florida to Arizona: New York Times, July 11, 2011, accessed July 12, 2012, at http:// U.S. Geological Survey, 2012e, Streamflow of 2011 – Water www.nytimes.com/2011/07/12/us/12drought.html?_ year summary: U.S. Geological Survey, accessed August 8, r=1&pagewanted=print. 2012, at http://waterwatch.usgs.gov/2011summary/. 46 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

U.S. Geological Survey, 2012f, Time series plot of below normal 7-day average streamflow compared to historical streamflow for the day of the year (Oklahoma): U.S. Geological Survey, accessed July 16, 2012, at http:// waterwatch.usgs.gov/?m=pa07d_dry&r=ok&w=pa07a_ dry%2Cplot. Vance, Brian, ed., 2007, Oklahoma water atlas: Oklahoma Water Resources Board, 190 p. Vaughn, C.C., and Atkinson, C.L., 2012, Drought effects on mussels in southeastern Oklahoma rivers: 2011 Oklahoma Water Research Symposium, October 18-19, 2011, Norman, Oklahoma, accessed July 12, 2012, at http://water.okstate. edu/programs/symposium/2011-symposium/2011-abstracts/ Vaughn.pdf. Wood, W.W., 2000, Ground-water recharge in the Southern High Plains of Texas and New Mexico: U.S. Geological Survey Fact Sheet FS–127–99, 4 p. Appendixes 1–4 47

Appendixes 1–4

Photographs of Selected Sites at Normal/High-Flow Conditions and Drought/Low-Flow Conditions, 2007–12 48 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma ograph ograph h o t h o t P P

S S G G S S U U

, s a , o i a v S

n d r e w . A A

J . J . . W Looking east from the northwest corner of Lake Overholser near Ramsey Road in Oklahoma City, Oklahoma, during normal conditions in July 2012 and drought Looking east from the northwest corner of Lake Overholser near Ramsey Road in Oklahoma City,

Appendix 1. conditions in September 2011. Appendixes 1–4 49

W.J. Andrews, USGS Photograph

S.J. Smith, USGS Photograph

Appendix 2. Dock on southwestern corner of Lake Hefner in Oklahoma City, Oklahoma, during normal conditions in July 2012 and drought conditions in October 2011. 50 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

W.J. Andrews, USGS Photograph

J.C. Scott, USGS Photograph

Appendix 3. Marina at the southwestern corner of Lake Hefner in Oklahoma City, Oklahoma, during normal conditions in July 2012 and drought conditions in September 2011. Appendixes 1–4 51

J.A. Savoia, USGS Photograph

Appendix 4. North Canadian River near Calumet, Oklahoma, during floods of July 2007 and drought conditions in July 2011. 52 Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma

Publishing support provided by Lafayette Publishing Service Center Shivers and others—Hydrologic Drought of Water Year 2011 Compared to Four Major Drought Periods of the 20th Century in Oklahoma—SIR 2013–5018 07 3364 1 8141 ISBN 978-1 4113 3640-7 97 Printed on recycled paper