The Water Supply Challenge: We Want Our Water

By Susan Seacrest

Legally mandated Republican River water flows, a rapidly growing ethanol industry, and the growing influence of wildlife and environmental advocates share a common refrain — "We want our water!" This message has been growing in volume thanks to a multi-year drought and increasing pressure from multiple water users to stretch precious water supplies. So how do we address this challenge? As an educator with The Groundwater Foundation, I believe understanding how water works is a good place to begin.

The hydrologic cycle

All water on earth is constantly on the move through the hydrologic cycle. Surface water evaporates from the earth by the energy of the sun, water vapor forms clouds in the sky, water vapor condenses and falls to earth, precipitation runs from high to low areas or seeps into the ground and is stored as groundwater. Surface water flows at various speeds depending on gradient and volume, while groundwater tends to travel slowly and is dependent on soil type and local geology. Hydrologically connected, groundwater and surface water exist as a single resource. Surface water seeps into groundwater, and groundwater, in certain cases, can contribute significantly to surface water.

As a result of this dynamic process, there is no "new" or "lost" water. Globally, water perpetually moves through the hydrologic cycle and is continually reused. However, within the context of a specific river basin, there is the potential for "new" (precipitation) and "lost" (consumption) water. In a river basin such as the Republican River watershed, water may be used over and over, but ultimately much of it is consumed through direct evaporation from land, plant, and built surfaces and evapotranspiration (ET) through growing plants. As Nebraskans we cannot change the hydrologic cycle, but we can recognize relevant processes and learn to manage each part of it as efficiently as possible.

Using versus consuming

Two examples illustrate the differences between using water and consuming water.

In North Platte, residents shower, wash their cars and utilize water as part of Bailey railroad yard maintenance. These might seem at first glance to be consuming water, but the reality is that they are, for the most part, nonconsumptive uses. This is because most of the water from showers, washing cars, and industrial manufacturing and maintenance drains to a water-treatment plant where it is discharged into a receiving surface water body or aquifer. From there, it is used again. However, a small amount of the municipal water, such as the steam from showers and ET from lawns and gardens, is consumed and leaves the area — unavailable to the good folks of North Platte, although the citizens of Des Moines may get a thunderstorm later!

In Mahoney State Park, nonconsumptive water use includes most of the water in the swimming pool and water utilized by people for fishing or boating. Consumption occurs when water evaporates from the hot pavement around the pool or thirsty tourists, who drank water from the park, drive home to Des Moines in time to get rained on from that thunderstorm! However, most of the water at the park is available for use again and again.

Water comes, water goes

In short, the hydrologic cycle giveth and the hydrologic cycle taketh away. On average, 90 million acre-feet of water fall on the state annually as precipitation. Interestingly, Nebraska’s average annual precipitation varies more east to west than almost any other state. For every 25 miles from east to west, there is about one inch of rainfall variability. The majority of Nebraska’s precipitation, and therefore water supply, occurs in the eastern half of the state. Extreme southeast Nebraska generally receives between 34 and 36 inches per year, while extreme western Nebraska in the panhandle receives only 14 to 16 inches. At roughly the same latitude, there is as much or greater precipitation variability across Nebraska as there is from the East Coast of the United States to Nebraska.

However, 90 percent of this 90 million acre-feet of precipitation never makes it to Iowa or anywhere else; rather, it is consumed in Nebraska at the surface through plants and evaporation. Of the remaining 10 percent:

*Approximately 5–8 percent, or about eight million acre-feet, runs off and flows out of Nebraska annually.

*Approximately 2–5 percent is available as recharge to groundwater.

In addition to precipitation, on average, approximately one million acre-feet of surface water flows into Nebraska annually. Most experts estimate that groundwater inflows and outflows generally balance on an annual basis.

What can we do about it?

What do these facts mean for Nebraskans? It’s important to remember that much of Nebraska is relatively dry and there is currently no program for directly importing or exporting water from one part of Nebraska to another. However, we can work towards making the water we do have more beneficial by:

*Increasing efficiency through converting flood irrigation to dropped-hose center pivots or installing efficient water appliances.

*Minimizing nonbeneficial consumption by invasive plants like salt cedar.

*Conducting research about new conservation practices, such as adding polymers to soil to help reduce large-scale soil evaporation.

*Implementing best practices known to reduce evaporation, such as no-till farming.

*Bringing consumption into line with available supplies, which means raising crops that are appropriate for the amount of water available.

*Exploring new options for aquifer storage and transport.

*Continuing to support, with tax dollars if necessary, the development of new technologies and practices that increase efficiency or decrease total consumptive use.

*Exploring the use of water budgets as a planning and allocation tool.

However, even these ideas may not guarantee that Nebraska will have more water to appease irrigators and municipalities in Kansas. If the water isn’t used for irrigation, it stays underground, doesn’t run off into nearby surface water streams, and stays in Nebraska. If the water in question is groundwater, it might take decades to travel as far as Kansas — too late for staving off additional lawsuits. Past practices may mean a big payday for Kansas, but the legal tangle with Kansas should not be the focus of Nebraska’s statewide water strategy.

Rather, it is more important to move forward with a commitment to putting every drop of water to beneficial use right here, and to taking steps towards using and consuming water in a sustainable way. The following actions can, in time, make more water available for a broad spectrum of activities:

*Maximizing the availability of water through best practices like no-till farming, testing soil regularly for moisture content and subsequently timing the application of water for maximum plant benefit.

*Protecting water quality at a level that increases the options for its use and, as a result, expands water availability.

*Finding new ways to reduce evaporation from soil, paved surfaces, and crop surfaces.

*Enacting policies that introduce new tools for water management such as water leasing and interbasin transfers.

*Requiring rural and urban areas to meet sustainable consumption benchmarks.

*Creating public/private partnerships to provide expertise and resources for all the above activities.

Let’s get going

The Republican Basin is a crystal ball warning us to immediately launch a large-scale effort to conserve and protect Nebraska’s water resources in every basin, whether currently threatened or not. In the past, we’ve been more eager to fix the blame than the problem. Increasing water efficiency, beneficial use, and decreasing water consumption is the responsibility of us all. Everyone consumes water with every drink we take and every meal we eat. Understanding this means that each of us needs to be part of funding water programs, not just in the Republican River Basin but in every part of Nebraska over the long term.

The Groundwater Foundation’s annual conference, "Bridging the Gap Between What Is Known and What Is Practiced," will examine these very issues in depth on Nov. 28–29, 2007, at the Sheraton Lakewood Hotel in Denver, Colo. If attending the conference isn’t possible, another educational option exists. The Groundwater Foundation and the Nebraska Water Resources Association have developed an educational PowerPoint presentation called "One Nebraska, One Water" on the topic of understanding water use and water consumption. Both the conference and the presentation are geared for the average citizen and aim to inspire needed changes in policy and practice.

We all want our water—and if we begin now to understand its value and adjust our practices accordingly, we may just have enough to go around.

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