Oklahoma Water Resources Center

A Path Forward for Oklahoma’s Groundwater Monitoring and Assessment

12/15/2015

by Joshua Cross

It is commonly said that sound research and data leads to sound policy, and that phrase rings especially true for water resources. As recommended by the Oklahoma Comprehensive Water Plan, the state of Oklahoma is improving our understanding of groundwater as part of recently created Groundwater Monitoring and Assessment Program (GMAP). This program is comprised of approximately 750 monitoring wells in Oklahoma's 21 major aquifers sampled on a five-year rotation, and represents Oklahoma’s first long-term aquifer-based sampling to be phased in by 2017. A recent presentation at the 2015 Oklahoma Governor’s Water Conference and Research Symposium held December 1-2 in Norman highlighted the usefulness of such a monitoring and assessment program moving forward.

James J. Butler Jr., senior geohydrologist for the Kansas Geological Survey, presented a keynote titled, “Assessing the Future of the High Plains Aquifer.” Butler demonstrated some of methods the Kansas Geological Survey has undertaken to measure groundwater level and use in the High Plains Aquifer in order to better predict future conditions based on their prior appropriation groundwater law system.

The High Plains Aquifer covers portions of eight states, including western Kansas and the Oklahoma panhandle. “This is one of the largest and most important aquifers not just in the country but in the world because of the critically important agricultural production that it supports,” Butler said.

Butler’s presentation focused on one significant portion of the High Plains Aquifer, the Ogallala. “The Ogallala Aquifer in western Kansas is under stress,” Butler said. “In southwest Kansas, we have cumulative declines in water level of 60 to 70 feet since 1996.”

Butler also noted significant declines in the saturated thickness of the aquifer since the onset of wide-scale pumping for irrigation. “In parts of Kansas, the Ogallala has lost up to 60% of the saturated thickness,” he said.

 “We are in relatively dire straits in certain parts of Kansas,” Butler said. “As that aquifer thickness diminishes, the ability of the aquifer to readily yield water to wells diminishes, so well yield diminishes and the depth to water increases, making it more expensive to bring water to the surface.”

Butler attributes these declines in saturated thickness to increased groundwater use and low natural recharge, which has a significant impact on the agricultural industries. “These factors put stress on the agricultural community in western Kansas,” he said.

In order to measure water level changes and water use, the Kansas Geological Survey and regional Groundwater Management Districts collect data that they hope will answer questions about the future. Every January, they measure water levels in approximately 1,400 wells across the High Plains Aquifer. “We’ve done that for decades,” Butler said. “That shows us how the water levels are changing.”

Additionally, the Kansas Geological Survey employs monitoring wells that take continuous measurements every 30 minutes or 2 hours. The data is then sent out by telemetry and posted publicly on the Internet. “They’ve got eight wells focusing on the Ogallala that tell us how the aquifer responds to active pumping,” Butler said. “This gives us a lot of information about what the future holds for different portions of the aquifer in western Kansas.” A subset of the wells in the GMAP in Oklahoma will be used similarly for trend monitoring.

While much of the data collected from these wells show declines in water levels and saturated thickness, the data also point to hope for the future. “What we’re showing is that practically feasible reductions can make a difference,” Butler said. “These may only be short term stabilizations of water level, depending on where this inflow comes from. So we at the Survey are spending a lot of time trying to nail that down so that we can begin to speak with a little bit more confidence in terms of the future.”  He emphasizes that sometimes simpler analysis techniques can be used as opposed to more complex groundwater flow models in determining available groundwater supplies. Similar to Oklahoma, regional or more localized planning and water management is also a key aspect of water management in the future.

Butler says it would be impossible to overemphasize the importance of collecting water data. “If we’re going to make wise, scientifically-sound decisions about our natural resources, we need data. Without data, we’re just guessing in the dark.”

The GMAP will be critically important for Oklahoma to meet its Water for 2060 Act goal of using no more freshwater in 2060 than the state did in 2012. You can learn more about the fundamentals of groundwater hydrology and groundwater research by visiting our Groundwater page.

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