Using Improved Irrigation Technology and Water Conservation to Meet Future Needs
By Ric Jensen
The Ogallala Aquifer is one of the largest groundwater resources in the world and represents one of Texas’ largest water sources. As a result, several innovative programs have been developed to conserve, manage and protect this critically important groundwater formation.
The Ogallala stretches across parts of eight states from South Dakota to Texas and covers 174,000 square miles, including 36,080 square miles in the Texas High Plains. According to recent estimates, the aquifer contains roughly 3.27 billion acre feet (ac-ft) of water, of which 417 million ac-ft are in Texas.
How important is the Ogallala to Texas and the United States? Most of the water pumped from the Ogallala is used for agricultural irrigation. Data from the U.S. Department of Agriculture show that farmland irrigated by the aquifer represents 65 percent of all the irrigated acreage in the nation.
Current irrigation water use for the Texas High Plains totals more than 6.1 million ac-ft but is predicted to decline to 4.8 million ac-ft by 2060, according to data developed by regional water planning groups.
Annual measurements of the depth to groundwater by the High Plains Underground Water Conservation District (HPUWCD) provide insights into trends throughout its 15 county service area. HPUWCD data show average declines of 1.28 feet per year from 1994 to 2004.
Thanks to the efforts of several organizations including groundwater conservation districts, Texas A&M University Agricultural Research and Extension Centers in Amarillo and Lubbock, U.S. Department of Agriculture – Agriculture Research Service (USDA-ARS), Texas Tech University and West Texas A&M University, many farmers throughout the Texas High Plains have adopted a variety of water-saving practices. These include low energy precision application (LEPA), center pivot irrigation systems, low elevation sprinkler application systems, subsurface drip irrigation, surge flow irrigation, the use of furrow dikes and reduced tillage.
As a result, overall water use efficiency among agricultural producers in the region has jumped from 50 percent in the 1970s to as much as 90 percent today. Research and Extension demonstrations with Texas farmers show that LEPA and subsurface drip irrigation systems are extremely efficient. Roughly 95 percent of water applied using these technologies contribute directly to crop growth.
The Ogallala Aquifer is located in a semi-arid region that receives limited rainfall, which provides little if any recharge. Only about 18 inches of rain falls in the region each year while potential evaporation losses from sustained high temperatures and winds total 70 to 80 inches annually. Therefore, the aquifer is a finite resource that is gradually being depleted.
Some of the challenges facing the Texas High Plains region today include increasing energy costs to pump groundwater, declining aquifer levels and proposed plans to market and export groundwater from the region.
Several programs are now underway that will influence the region’s water quality, quantity and use.
Researchers at USDA-ARS, Texas A&M University, Texas Tech University, West Texas A&M University and Kansas State University are working to make agricultural water use more efficient, determine the economics of water conservation and educate farmers and other water users about conservation practices.
An agricultural water conservation initiative enabled by Senate Bill 1053 was passed in the 78th session of the Texas Legislature. The bill is designed to transfer water-saving technologies to agricultural producers. The Texas Water Development Board will work with cooperators to demonstrate water conservation methods at large-scale sites involving several farmers.
