Click through the interactive Google Fusion Tables infographic to see how water use has changed over the last two decades, as well as how these trends relate to fluctuation of groundwater tables within the Ogallala Aquifer since the 1940s.
The Great Plains are home to some of the largest cotton and wheat harvests in the United States. The eight-state region is also home to the country’s biggest cattle feedlots. But to sustain this $US 30 billion agricultural bounty, the region relies on an increasingly unsustainable water supply from the Ogallala Aquifer, the nation’s largest underground freshwater source.
Prime farm regions in the Southern Plains of Texas and Kansas have only a few decades of water left, according to groundwater experts. For some who are living on the Ogallala’s margin, the supply is already gone. A fierce drought is adding pressure and urgency to a chronic problem of unsustainable water use — federal weather data indicates that the 42 months from October 2010 to March 2014 were the driest such period in the history of the Southern Plains, even worse than the Dust Bowl years.
Farmers in Texas and Kansas are taking different paths to save water. Scuttling decades of habit, legal precedence, and cultural resistance, agriculture on the Great Plains is reluctantly moving toward decisions on water use, crop yields, and profits that have been put off for decades. Farmers in Sheridan County, Kansas, for instance, are embracing a 20 percent cut in water use, one of the strictest water limits on the Great Plains. In Texas, too, groundwater districts are experimenting with pumping limits, though these state-regulated jurisdictions are treading more carefully since there is a longstanding Texan tradition of viewing access to groundwater as an inviolable property right.
To fairly and accurately compare the water use in the Ogallala region of both states, it is necessary to look at their geographical size, population demographics, and agricultural prowess.
Texas has 43 counties that make up 27.3 million total acres within the Ogallala Aquifer. In 2007, 93 percent of that was devoted to farmland in general and 29 percent was cropland. Meanwhile, Kansas has 32 counties and 18.3 million acres within the Ogallala region; 91 percent was farmland and 36 percent was cropland. In 2007, the Ogallala region of Texas had about 20,000 farms — each 1,279 acres — compared with 13,000 farms of 1,332 acres each in the Ogallala region of Kansas. In other words, though Texas as a whole is more than three times the size of Kansas and has nearly four times as many farms as Kansas (250,000 compared with 65,000 in 2007), their Ogallala regions are quite comparable. In 2007, there were about 1.5 farm operators per farm in the Ogallala regions of both Texas and Kansas, though Texas Ogallala had more hired farm workers (25,000 compared with 15,000 in Kansas.) In general though, there are about five times as many Texans living in the Ogallala region than Kansans.
What is not comparable is the water usage that occurs within these two regions. Though more than 95 percent of total withdrawals in the both regions are from fresh groundwater resources, and more than 95 percent of those fresh groundwater withdrawals are devoted to irrigation, the Texas Ogallala has had about 20 percent increase in withdrawals since 1985 while the Kansas Ogallala region has cut withdrawals by nearly 50 percent.
Click the image below to launch an interactive Google Fusion Tables map that shows data on water withdrawals by county in Texas and Kansas from 1985 to 2005. Click the buttons at the top to choose total water use — which includes saline supplies and city use — or fresh groundwater use, which is what mostly occurs in the Ogallala region. Click a county to learn more about the breakdown of its total water use as it relates to fresh groundwater use. The 75 counties that fall within the Ogallala Aquifer are bordered in light blue; click on these counties to learn more about changes in groundwater levels since the 1940s. (Data gathered from U.S. Geological Survey and the U.S. Department of Agriculture.)
In 2005, there were 22.8 million Texans, 971,000 of which lived in the Ogallala region. Likewise, there were 2.7 million Kansans, 209,000 of which lived in the Ogallala region. By percentage, this means that 5.8 percent of Texans lived in Ogallala region, compared with 8.6 percent of Kansans. Though Texas population as a whole increased nearly 40 percent between 1985 and 2005, the Ogallala region of Texas only increased by 2.7 percent, since the lone star state’s population increases occurred mostly in its big cities. Meanwhile, the population of Kansas as a whole increased by only 12 percent, and the Ogallala region of Kansas actually experienced a slight decrease of just over one-quarter percent. In other words, over the past two decades, people have moved out of the Kansas Ogallala region, and only a few people have moved into the Texas Ogallala region.
Farms and Farm Workers
Texas had an increase of more than 58,000 farms from 1987 to 2007, but just over 3,000 of those occurred within the Ogallala region. Meanwhile, Kansas actually decreased the number of farms by 3,000, about half in each the non-Ogallala and Ogallala regions. As a whole, Texas has nearly four times as many farms as Kansas (250,000 compared with 65,000 in 2007) but there are only 7,000 more farms in the Ogallala region of Texas than in Ogallala region of Kansas (about 20,000 compared with 13,000). Over the past two decades, total farm acreage dropped in Texas by 27,000 acres and by 282,000 acres in Kansas. In 2007, farm size in the non-Ogallala region was 458 acres per farm in Texas and 558 acres per farm in Kansas. In the Ogallala region, it was 1,279 acres and 1,332, respectively.
Farming on the Great Plains is highly mechanized, meaning that there is not much need for farm workers. On average, there are about 1.5 farm operators per farm in both Texas and Kansas as a whole, as well as in the Ogallala region. Between 1987 and 2007, about 15 percent of the hired farm workers in Texas were in the Ogallala region, compared with about 30 percent in Kansas Ogallala. In 2007, there was about half of a hired farm worker per farm in the non-Ogallala regions of both states, and about 1.25 hired farmworkers per farm in the Ogallala region. There were about 1.7 hired farm workers in Ogallala Texas to every one in Kansas (25,000 to 15,000).
Refining the Data
When looking at total water use from all sources — surface and groundwater sources, fresh and saline supplies — Ogallala water use made up about 19 percent of the 26.7 million gallons of daily Texas withdrawals in 2005 and 53 percent of the 3.8 million gallons of daily withdrawals in Kansas. It is important to note that much of the total withdrawals in Texas, however, are attributed to saline supplies and to city use, neither of which have much to do with water use in the Ogallala region. Thus, the data were refined to show only fresh groundwater use, because, of the total water use that was occurring in the Ogallala regions, more than 95 percent was attributed to fresh groundwater use. When clicking between total water use and fresh groundwater use, notice the major differences: essentially, the “hot spots” in the cities and along the coast of Texas disappear in the fresh groundwater map, thus the majority of fresh groundwater use is seen in the western agricultural region of the Ogallala Aquifer in both states.
Fresh Groundwater Use for Agriculture
Despite starting out around the same for fresh groundwater withdrawals in 1985 (4 million gallons per day for the Texas Ogallala region compared with 3.5 million for Kansas Ogallala), Texas had increased fresh groundwater use by about 16 percent in 2005 (to 4.8 million gallons per day), whereas Kansas had a 45 percent reduction (down to 2 million gallons per day). Likewise, fresh groundwater withdrawals for irrigation have gone up 20 percent in Texas Ogallala and have gone down 47 percent in Kansas Ogallala (from 3.8 million gallons per day in 1985 to 4.5 million in 2005 and from 3.5 million to 1.8 million, respectively). In both regions, more than 95 percent of fresh groundwater withdrawals were devoted to irrigation, consistently, over the last two decades.
Between 1985 and 2005, the Ogallala region of Texas has remained fairly constant in how many acres of land were irrigated — around 4.3 million acres. What has changed, however, is how that cropland was irrigated. Texas Ogallala has more than double the number of acres that are sprinkler irrigated (from 1.4 million to 3.2 million), meaning that the region has cut wasteful flood irrigation by nearly two-thirds (from 2.9 million acres to 1.1 million acres). In the Ogallala region of Kansas, the story is much the same: there has been consistently about 2.1 million acres that were irrigated, sprinkler irrigation has tripled (from 617,000 acres to 1.9 million acres, and flood irrigation has been cut to nearly one-tenth of 1985 levels (from 1.5 million acres to 193,000). When looking at how irrigation methods have changed over the past two decades between the two regions, the story becomes even clearer.
Shades of blue are non-Ogallala counties and shades of red are Ogallala counties. Dark blue shows the percentage of acres that are flood irrigated in the non-Ogallala region; notice that Texas has decreased flood irrigation from about 80 percent of its irrigation practices to about 50 percent, while decreases in Kansas have gone from about 35 percent to about 13 percent. Dark red shows the percentage of flood-irrigated acres in the Ogallala region: notice that Texas nearly has cut by about half, from 67 percent to about 25 percent, and Kansas has made substantial cuts, from 70 percent to about 9 percent.
In other words, the Ogallala region of Texas is making better strides to improve irrigation techniques than the non-Ogallala region of the state, but even the efficiency-minded Ogallala region of Texas is no comparison for the non-Ogallala region of Kansas. It is also good to note that, though the Ogallala regions of both Texas and Kansas had nearly three-quarters of irrigated acreage under flood irrigation in 1985, Texas has cut this to only one-quarter while Kansas has cut to one-tenth. Across the board, it seems, Kansas is doing a better job of getting in line with irrigation efficiency techniques.
This map was created by Jordan B. Bates and Aubrey Ann Parker, Circle of Blue’s web producer and chief data analyst, respectively. Contributors included Brett Walton of Circle of Blue, with assistance from Sreeram Balakrishnan of Google Fusion Tables. Additional help from Sheng Long and Robert Queen, students with the Columbia Water Center in New York City. Columbia interns were overseen by Upmanu Lall and Margo Weiss. Reach Circle of Blue’s data team at firstname.lastname@example.org/~circl731.