In Western Kansas, for example, water levels have declined by up to sixty percent in some areas as the gap between what is withdrawn for irrigation and what is recharged continues to expand. In northwest Texas, so much water has been pumped and so little recharged that irrigation has largely depleted the aquifer in the area. A study from Kansas State University predicted that the aquifer would be seventy percent depleted by if irrigation practices do not change.
However, the study further predicted that the aquifer could potentially last up to one hundred more years if all farmers in the region cut their use by twenty percent.
Aside from the devastating effects on agriculture, a study recently published by a team of stream ecologists concluded that depletions to the Ogallala Aquifer are also leading to fish extinctions in the region. Streams and rivers that depend on the aquifer are drying out after decades of over-pumping. The study found pumping to be associated with collapses of large-stream fish and the simultaneous expansion of small-stream fish.
This creates a catalyst for biotic homogenization, which in turn leads to less resilient aquatic communities and loss of ecosystem functions.
The study predicts an additional loss of kilometers of stream by , as well as the continued replacement of large-stream fish by fish suited for smaller streams.
The High Plains states are accustomed to periods of water shortages, and, accordingly, these states have all established the statutory or regulatory power to strictly control groundwater use. However, while the High Plains states all have the legislative authority to regulate use of the Ogallala aquifer to ensure sustainable use, some states have been more or less hesitant to exercise those powers.
Those states that do not strictly regulate groundwater have instead chosen to leave conservation in part to the water users themselves. Two states in particular have highly diverged in their approach to regulating groundwater—Kansas and Nebraska.
Each state has legislation in place allowing the government to force farmers to reduce water use, but while Nebraska has actively used that power, Kansas has been much more hesitant. In exercising that power, the chief engineer can dramatically cut water applications for farmers and close applications for new water rights.
The chief engineer has exercised that power several times in the last few decades, but Kansas state officials are often reluctant to do so. We would like to see groups of irrigators come together and work out a solution.
These plans are then subject to approval by the state. Once approved, the plan becomes legally binding. One group of farmers has set up a ninety-nine square mile conservation zone where they agreed to a twenty percent reduction in irrigation for five years. After four years, they have steadily achieved their twenty percent reduction rate while, significantly, not seeing a reduction in profits.
With a liquid treasure below their feet and a global market eager for their products, farmers here and across the region have made a Faustian bargain—giving up long-term conservation for short-term gain.
Like coal or natural gas, groundwater is a valuable resource. The challenge is to stretch the life of the aquifer to benefit future generations of farmers and those who depend on their products. In Garden City, however, the severity of their circumstances is already forcing farmers to take action. They are grappling with how to maintain successful agricultural operations while relying on less and less water, an issue that water users throughout the region, and the world, must eventually face, Rude says.
Tapping the Aquifer On a hydrographic map, the Ogallala is a Rorschach inkblot that some describe as the shape of a mushroom, others the South American continent. Millions of years ago, when the southern Rocky Mountains were still spewing lava, rivers and streams cut channels that carried stony pieces of the mountains eastward. Sediment eventually covered the area and filled in the ancient channels, creating vast plains.
The water that permeates the buried gravel is mostly from the vanished rivers. It has been down there for at least three million years, percolating slowly in a saturated gravel bed that varies from more than 1, feet thick in the North to a few feet in the Southwest.
Until recently, most of the region had no permanent settlements. Native American tribes who used the open plains for seasonal hunting retreated to river valleys to pitch their tents. When Spanish conquistador Francisco Vazquez de Coronado came through in looking for the gold cities of Cibola, he marched his iron-clad men to the brink of exhaustion, never knowing that water to quench their near-maddening thirst lay mere yards beneath their boots. Similarly, cattle drives in the s and s collapsed in a perfect storm of drought, overgrazing and falling meat prices.
And early attempts at farming were plagued by soil erosion and cycles of drought that culminated in the s Dust Bowl. Industrial-scale extraction of the aquifer did not begin until after World War II.
Diesel-powered pumps replaced windmills, increasing output from a few gallons a minute to hundreds. Over the next 20 years the High Plains turned from brown to green. The number of irrigation wells in West Texas alone exploded from 1, in to more than 66, in But the miracle of new pumping technology was taking its toll below the prairie. By water levels had dropped by an average of nearly 10 feet throughout the region.
In the central and southern parts of the High Plains some declines exceeded feet. Concerned public officials turned to the U. Geological Survey, which has studied the aquifer since the early s. What they found was alarming: yearly groundwater withdrawals quintupled between and In some places farmers were withdrawing four to six feet a year, while nature was putting back half an inch. In Cimarron and western Texas counties, a younger formation of shale and sandstone called the Dockum group overlies the redbed.
Other formations, including the Dakota Sandstone and Morrison Formation, also are found in the Oklahoma Panhandle [4]. The Panhandle region has a semi-arid climate with the average annual rainfall of about 20 inches during the past years Drought is common in the area, with one out of every six years having received less than 16 inches of rainfall during the same year period.
The Ogallala aquifer supplies more than 98 percent of total water demand in the Oklahoma Panhandle and other sources e. Alluvial aquifers, which are shallower and generally connected to surface water resources, are limited.
Local rivers and creeks mainly the Beaver River and the upper Cimarron River can have periods of low to no flow and are unreliable as a major water supply. Optima Reservoir, the only major Panhandle reservoir, does not sustain water. Irrigation is the largest use of water in the Panhandle. Based on crop mix data, there are approximately , acres of irrigated land in Cimarron, Texas and Beaver counties, requiring more than , acre-feet of water per year [9].
This is about 85 percent of the total water demand in the region and is expected to increase to about , acre-feet by The major irrigated crops are grain corn and wheat, accounting for about three-fourths of the total irrigated area. According to the USDA National Agricultural Statistics Service, the total harvested area of irrigated corn and wheat in was more than , and 65, acres, respectively. Grain sorghum ranked lower, with a total irrigated area of about 20, acres.
The expansion of irrigated agriculture in Oklahoma Panhandle has been a major driving force for economic development and prosperity of this region. However, this growth has come at the cost of declining non-renewable water resources. Figure 2 demonstrates the cumulative number of irrigation wells drilled in each of the four major Oklahoma counties overlying the Ogallala aquifer. Figure 2. The cumulative number of irrigation wells drilled in each of the four major Oklahoma counties overlying the Ogallala aquifer.
Since the predevelopment period prior to , about 3, irrigation wells have been drilled into the Ogallala aquifer. The largest number of drilled wells more than half were in Texas County, followed by Cimarron, Beaver and Ellis counties. Hence, it is not surprising that the largest decline in groundwater has been experienced in Texas County. According to the Oklahoma Water Resources Board, water levels in the Ogallala aquifer have declined more than 70 feet in Texas County and more than 50 feet in Cimarron County since predevelopment.
These large declines can be attributed to the high density of irrigation wells. Erosion from the Rockies filled in the ancient channels of water and valleys. This is how the aquifer formed over time and became buried underground. Water in the aquifer generally flows from west to east at a rate of one foot per day. The further north you go, the better the water quality. Over the course of the last years especially, contaminants have leaked into the aquifer.
This is due to factors such as irrigation density, nitrogen application, and climate change. We will revisit these contaminations and the resulting depletion later on. Ogallala, Nebraska is still a town you can drive to today, with a population of under 5, residents.
As is often the case in US history, colonial-settler communities adopted this city name from the people whose land was stolen — erasing the history of genocide and dispossession that occurred as the first and many subsequent waves of white supremacy spread across the continent, keeping only the name.
But the original inhabitants and stewards of this land are of the Lakota Nation. In , the Fort Laramie Treaty established the land stretching from Canada, south to Kansas, east to Wisconsin, and all the way west through Wyoming as territory of the Great Sioux Nation Sioux is the name the Colonists use d to refer to the Lakota nation.
Over time, war and massacre with individual settlers and the United States, that territory was stripped from the nation. Today, the existing borders of the Pine Ridge Reservation are the remaining territory of the Oglala Lakota. It is the second poorest area of the United States. Sources to consider include Indian Country Today , Honor The Earth , and news features on various national news sites. This is water that people use to sustain crops and supports livestock.
This is a system that allows farmers to grow crops even in times of drought. The high plains aquifer is vast, to be sure. But it is not endless. A recent study estimates that water levels are dropping.
Still, other wells in more northern regions have risen. Ultimately, if you look at the climate of the land above the aquifer, you can imply that lower water levels mean devastating impacts are just around the corner. Because of this, the aquifer has a very slow recharge rate. Where water levels drop, the price of water goes up.
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