Exploring The Sustainability Of The Ogallala Aquifer Acknowlegment
Exploring The Sustainability Of The Ogallala Aquifer
Acknowlegment Erin O’Brien ØKansas State University Biological & Agricultural Engineering Ø Who in Summer 2001 studied the Ogallala in West Kansas under: • National Science Foundation • Research Experience for Undergraduates • Mc. Nair Scholar’s Program
Introduction Ø The Ogallala aquifer lies within the Great Plains region. Ø This groundwater source is a part of the High Plains aquifer system. • In Kansas the High Plains aquifer system and the Ogallala aquifer are typically the same.
--(Guru 2000)
Direct relationship of the Aquifer and the Dust Bowl
High Plains (Ogallala) aquifer High Plains Ø Precipitation drops to less than 50 cm per year (20 inches) approximately west of a line that divides the U. S. in half
High Plains (Ogallala) aquifer Ø The paradox is that this semi-arid region is the source of much of our grain crops. • Kansas, the wheat state, is too dry to produce wheat unless water is added by irrigation. • Irrigation waters for the Great Plains states (South Dakota south to Texas) are taken from a single massive aquifer, the High Plains or Ogallala aquifer.
High Plains (Ogallala) aquifer Ø The paradox is that this semi-arid region is the source of much of our grain crops. • Kansas, the wheat state, is too dry to produce wheat unless water is added by irrigation. • Irrigation waters for the Great Plains states (South Dakota south to Texas) are taken from a single massive aquifer, the High Plains or Ogallala aquifer.
Recent Drought http: //droughtmonitor. unl. edu/
Micro or State level Scale Ø Western Kansas is a major economic source for Kansas: • 40% of the nation’s packaged beef comes from within 250 miles of Garden City, and • Kansas is 2 nd in the nation in cattle slaughter and 3 rd for red meat production.
Sustainability Ø “Meeting fundamental human needs while preserving the life-support systems of planet Earth is the essence of sustainable development. ” —(Kates, et al. 2001) Ø Since irrigation from the Ogallala taps ‘fossil’ groundwater there is an issue of sustainability of the current system.
Ogallala Ø The High Plains aquifer has been a source for irrigation water since the early 1900’s, but mainly post 1950’s Ø Approximately 170, 000 wells draw water from the aquifer
Ogallala Ø This has brought prosperity to an area described by Major Stephen Long in 1819 as "almost wholly unfit for cultivation and. . . uninhabited by people depending upon agriculture for their subsistence. "
Ogallala Ø The aquifer feeds the largest area of irrigation-sustained cropland in the world
Dimensions Ø The aquifer's saturated zone may be up to 425 m thick (About same as Empire State Bld. ) Ø Aquifer dimensions vary along its length. Ø It is always relatively shallow; the water table is typically less than 300 feet deep. Ø The aquifer contains more than 3. 3 billion acre-feet of water (1 acre-foot = ~326, 000 gallons), more water than Lake Huron.
Volume of groundwater in Ogallala aquifer restored by precipitation: ~10% Ø Unfortunately, the aquifer contains "fossil" water, Ø the product of a wetter paleoclimate associated with the end of the last ice advance. Ø although substantial recharge does occur in some areas from streams (e. g. Platte River, Nebraska). There is NO sufficient contemporary source for water to recharge the whole aquifer
History Ø Groundwater from the aquifer was first widely used in the 1930's in Texas. Subsequently approximately 11% of the groundwater supply has been extracted.
History Ø 1. 1930 -1950: water table depth remained constant as withdrawal was limited to a few wells Ø 2. 1950 -1985: water table depth declined from 65 m to 115 m • increasing numbers of wells • acreage in Kansas climbed from less than half a million acres in 1959 to nearly 2 million acres in 1978. Ø 3. 1985 - present: decline in water table depth slowed due to decreasing discharge attributed to: • heavier than normal rains • increased energy costs for pumping • improved irrigation technology
Eventually with little to no recharge all the water will be gone
Recent Events Ø Decrease in volume of groundwater pumped from Ogallala aquifer, 1980 -85: 19% Ø Largest Declines in the aquifer have occurred in southwest Kansas and the Texas Panhandle Ø Declines have been matched by population migrations from rural counties
Population Sink
Rapidly Aging Population
High Outmigration & Some of Poorest Counties in US
Groundwater Overdraft Ø Over the life of the aquifer the water table dropped 70 meters in parts of the Panhandle Ø Western Kansas used 38% of the groundwater in the underlying aquifer.
Kansas Study Area Facts Ø The Ogallala aquifer: • Underlies 134, 000 mi 2, • Is the largest body of groundwater in the U. S. • The porous rock layers were formed ~10 million years ago by fluvial deposition.
Ø Recall the High Plains aquifer is approximately equivalent to Lake Huron. Ø 30% of the water used for irrigation in the U. S. comes from the High Plains aquifer. Ø 10% percent of the drainable water in the High Plains aquifer underlies Kansas.
Ø The High Plains aquifer faces many different concerns, including purity, quality, quantity, and saturated thickness. Ø The Ogallala region has many concerns: • ~19% is covered by sand dunes; • Water consumption is 10 -40 times recharge • Local precipitation does not affect recharge
Ø Ogallala facts: • Only 15 -20% of the water is available for withdrawal and only 60 -80% of this is technologically accessible. • Kansas scientists say it may take 35 years for recharge water to reach the aquifer. (when it comes at all) • The water in the Ogallala is fossil water and is only available through groundwater mining.
History Ø The droughts of the 1930 s and 50 s made people realize that the climate changes of the region were simply cyclical variations. Ø Irrigation rapidly expanded following the drought of the 1950 s. Ø By 1972, ~40% of the available groundwater had been consumed.
Technology Ø In 1896 in Garden City, KS, a centrifugal pump was one of the first attempts at irrigation in Kansas. Ø Another pump was in use by 1911 in Scott City, KS. Ø In 1949, center-pivot systems were developed. Ø Drop tubes & subsurface drip irrigation (SDI) have become common recently.
Old fashion inefficient flood irrigation
More modern, more efficient center pivot irrigation
Rules/Regulations Ø In 1972 KS passed the GMD Act to: • Regulate groundwater, • Grant drilling permits, and • Ensure old water rights are protected. Ø Constraints exist on policies that would decrease water availability. Adjustments must be technically, financially, legally, and socially feasible.
Basic Issue Ø "'There's a point, ' explains Chief Engineer Pope, 'where too much emphasis on protecting individual interests means you can't protect the general public interest'" (Fund 1993, p. 24).
Sustainability Issues Ø Farmers irrigate for many reasons: • • To meet a specific crop need; To increase yearly income; As a result of success by other irrigators; and To maintain their water rights. Ø The number of irrigated acres is declining in all states. Ø Irrigation offers a climate substitute and enables increased yields.
Dry Farming not a real option Ø Recurrent droughts are a hazard for the region. Ø There were two prolonged droughts in the last century: • In the 1930 s and the 1950 s. Ø What will happen when the water is gone? • Two New Jersey scholars have proposed a “buffalo commons” national park. Popper & Popper.
Buffalo Commons
Ø The area has already been affected by a decreased flow in the Arkansas River due to diversion and pumping. Ø It has only recently began to flow again, after a Supreme Court ruling limited withdrawals.
Ø These pages show graphs indicating: • • Predevelopment saturated thickness, Current saturated thickness, The amount of groundwater depletion, and The number of years of usage remaining. --Schloss, et al. 2000.
The Ogallala Problem Ø Water level declines of 2 -3 feet per year in some regions are drawing concern of the aquifer drying up - first one in the U. S. This is due to pumping more water than is replaced through recharge, and only 10% is restored by rainfall. Large issues exist over contamination and salt water intrusion problems as well.
Sample Hydrograph
The Ogallala Future Ø Drawdown from 1998 to 2050 is predicted to be more than 150 feet in some areas given the forecast amount of pumping. Ø By 2010, parts of the aquifer in Oklahoma and Kansas are simulated as going dry. http--www. twdb. state. tx. us-gam-ogll_n-OG-n_report. pdf. url Dutton, A. R. , Reedy, R. C. , and Mace, R. E. (2001). Saturated Thickness in the Ogallala Aquifer in the Panhandle Water Planning Area: Simulation of 2000 through 2050 Withdrawal Projections.
Summary Ø Can the Ogallala aquifer be sustained? Ø History shows that farmers are adaptable to a variable climate. Ø Technological advances have greatly improved water use efficiency.
Ø The current irrigation-based economy can be sustained for several more decades. Ø We must plan for what will happen when irrigated agriculture and the associated agribusiness economy becomes a thing of the past.
Population in Decline Originator: p. buckley, 11/16/2010, source: National Atlas www. nationatlas. gov
Acknowledgements Ø Guru, Manjula V. , and James E. Horne. "The Ogallala Aquifer. ” Kerr Center for Sustainable Agriculture, Inc. <http: //www. kerrcenter. com/RDPP/ogallala. htm>. July 2000. Ø Kates, Robert W. , et al. “Sustainability Science. ” Science. Vol. 292, 641642: 27 April 2001. Ø Kromm, David E. , and Stephen E. White, eds. Groundwater Exploitation in the High Plains. Lawrence, Kansas: University Press of Kansas, 1992. Ø Schloss, Jeffrey A. , Robert W. Buddemeier, and Blake B. Wilson, eds. An Atlas of the Kansas High Plains Aquifer. Lawrence, Kansas: Kansas Geological Survey, 2000. Ø Dr. John Harrington, Jr. , Dept. of Geography, Kansas State University Ø Dr. David E. Kromm, Dept. of Geography, Kansas State University
Surviving the Dust Bowl – 1930 s https: //www. youtube. com/watch? v=c. Nuskt 7 Q_y 8
http: //www. youtube. com/watch? v=t. U 9 r 277 t. Be. U
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