The Perils of Groundwater Pumping

The excessive “mining” of our aquifers is causing environmental degradation on a potentially enormous scale.

The next time you reach for a bottle of spring water, consider that it may have come from a well that is drying up a blue-ribbon trout stream. The next time you dine at McDonald’s, note that the fries are all the same length. That’s because the farmers who grow the potatoes irrigate their fields, perhaps with groundwater from wells adjacent to nearby rivers. The next time you purchase gold jewelry, consider that it may have come from a mine that has pumped so much groundwater to be able to work the gold-bearing rock that 60 to 100 years will pass before the water table recovers. The next time you water your suburban lawn, pause to reflect on what that is doing to the nearby wetland. And the next time you visit Las Vegas and flip on the light in your hotel room, consider that the electricity may have come from a coal-fired power plant supplied by a slurry pipeline that uses groundwater critical to springs sacred to the Hopi people.

These and countless other seemingly innocuous activities reflect our individual and societal dependence on groundwater. From Tucson to Tampa Bay, from California’s Central Valley to Down East Maine, rivers and lakes have disappeared, and fresh water is becoming scarce. Groundwater pumping–for domestic consumption, irrigation, or mining–causes bodies of water and wetlands to dry up; the ground beneath us to collapse; and fish, wildlife, and trees to die. The excessive pumping of our aquifers has created an environmental catastrophe known to relatively few scientists and water management experts and to those who are unfortunate enough to have suffered the direct consequences. This phenomenon is occurring not just in the arid West with its tradition of battling over water rights, but even in places we think of as relatively wet.

As a country, we have dramatically increased our reliance on groundwater. This increase has dried up rivers and lakes, because there is a hydrologic connection between groundwater and surface water. Yet the legal rules governing water use usually ignore this link. This disconnection between law and science is a major cause of the problem. So too is our refusal to recognize the unsustainability of our water use. Significant reform is necessary if we are to prevent further degradation of our rivers, streams, lakes, wetlands, and estuaries.

Groundwater use and consequences

Groundwater pumping in the United States has increased dramatically in the past few decades. For domestic purposes alone, groundwater use jumped from 2.9 trillion gallons in 1965 to about 6.8 trillion gallons in 1995, or 24,000 gallons for every man, woman, and child. But domestic consumption is only a small fraction of the country’s total groundwater use, which totaled almost 28 trillion gallons in 1995. Farmers used two-thirds of that to irrigate crops; the mining industry, especially for copper, coal, and gold production, pumped about 770 billion gallons. Groundwater constitutes more than 25 percent of the nation’s water supply. In 1995, California alone pumped 14,500 billion gallons of groundwater per day. Groundwater withdrawals actually exceeded surface water diversions in Florida, Kansas, Nebraska, and Mississippi. In the United States, more than half of the population relies on groundwater for their drinking water supply. Groundwater pumping has become a global problem because 1.5 billion people (one-quarter of the world’s population) depend on groundwater for drinking water.

Groundwater is an extraordinarily attractive source of water for farms, mines, cities, and homeowners because it is available throughout the year and it exists almost everywhere in the country. During the various ice ages, much of the country was covered with huge freshwater lakes. Water from these lakes percolated into the ground and collected in aquifers. Unlike rivers and streams, which are few and far between, especially in the West, aquifers exist below almost the entire country.

The legal system has fostered our increasing use of groundwater by developing two sets of rules for allocating rights to divert water from rivers and lakes. In the East, the riparian system allows owners of property on rivers or lakes to divert water for a variety of purposes. In the West, the prior appropriation doctrine–the essence of which is “first-in-time, first-in-right”–gives superior rights to the earliest diverters. However, the legal system developed a completely different set of rules for controlling groundwater use. When U.S. courts developed groundwater law in the 19th century, hydrology was an infant science. In 1850, the Supreme Court of Connecticut explained that the movement of water beneath the surface of the earth moved according to principles that could not be known or regulated. “These influences are so secret, changeable, and uncontrollable, we cannot subject them to the regulations of law, nor build upon them a system of rules, as has been done with streams upon the surface,” the court said. This reasoning made sense in 1850; since then, however, the law in most states has not kept pace with advances in the science of hydrology. As a consequence, the legal rules have failed to conform with physical reality. Principles of either riparianism or prior appropriation govern surface water, whereas the “reasonable use” doctrine governs groundwater pumping. Under this doctrine, an owner of land may pump as much water as he or she desires so long as it is for a “reasonable use,” which is essentially no restriction whatsoever.

Overdrafting or “mining” groundwater creates serious problems. Because water is heavy, about two pounds per quart, more energy is needed to lift water from lower levels. The costs of this energy may be substantial: In Arizona, the electric energy to run a commercial irrigation well may cost $2,000 per month. The drilling of new and deeper wells may be required, which is often a considerable expense. Pumping from lower levels may produce poorer quality water because naturally occurring elements, such as arsenic, fluoride, and radon, are more prevalent at deeper levels in the earth, and the earth’s higher internal temperature at these levels dissolves more of these elements into solution. As the water deteriorates in quality, it may violate U.S. Environmental Protection Agency regulations, requiring either that the water be subject to expensive treatment processes or that the well be turned off, thus eliminating that source of water. Along coastal areas, overdrafting may cause the intrusion of saltwater into the aquifer, rendering the water no longer potable. This problem is quite serious in California, Florida, Texas, and South Carolina. Another consequence of overdrafting is the prospect of land subsidence, in which the land’s surface actually cracks or drops, in some cases dramatically. In California’s San Joaquin Valley, the land surface dropped between 25 and 30 feet between 1925 and 1977. Land subsidence has damaged homes and commercial structures and reduced property values. Pumping north of Tampa Bay in Pasco County has cracked the foundations, walls, and ceilings of local residents’ homes, resulting in lawsuits, insurance claims, and considerable ill will.

A final consequence of groundwater pumping is its impact on surface water, including lakes, ponds, rivers, creeks, streams, springs, wetlands, and estuaries. These consequences range from minimal to catastrophic. An example of the latter is the Santa Cruz River in Tucson. Once a verdant riparian system with a lush canopy provided by cottonwood and willow trees, groundwater pumping has lowered the water table, drained the river of its flow, killed the cottonwood and willow trees, and driven away the local wildlife. The river has become an oxymoron–a dry river–a pathetic desiccated sandbox.

How does a river go dry?

Fueled by the energy of the sun and the force of gravity, water continually moves through a succession of different phases, called the hydrologic cycle. The sun’s energy evaporates seawater from the oceans’ surface, leaving behind the salts and circulating the water into the atmosphere. After wind currents carry the moisture-laden air over land, the increase in relative humidity eventually causes the water to condense and produces precipitation. When the water falls to earth, some of it immediately evaporates into the sky, another portion runs off the land to creeks, streams, and rivers, and some infiltrates the ground, in a process known as recharge. A portion of the groundwater near rivers and streams eventually emerges from the ground, in a process called discharge, to augment the surface flows of rivers or streams. Groundwater pumping essentially interrupts this cycle by removing water, directly or indirectly, that would otherwise discharge from aquifers to rivers, streams, and other surface water bodies.

Groundwater and surface water are not separate categories of water any more than liquid water and ice are truly separate. The designations groundwater and surface water merely describe the physical location of the water in the hydrologic cycle. Indeed, groundwater and surface water form a continuum. In some regions of the country, virtually all groundwater was once stream flow that seeped into the ground. The converse is also true but not obvious. Consider the following puzzle: Where does water in a river come from if it has not rained in a while? The water comes from groundwater that has seeped from the aquifer into the river, in what’s known as base flow.

Groundwater pumping has dried up or degraded 90 percent of Arizona’s desert streams, rivers, and riparian habitats.

Whether water will flow from the river to the aquifer or vice versa depends on the level of the water table in the aquifer and on the elevation of the river. If the water table is above the elevation of the river, water will flow laterally toward the river and augment the flow in the river. In most regions of the country, this is the process that occurs. But as groundwater pumping lowers the water table, the direction of the flow of water changes. Once the water table is below the elevation of the river, water flows from the river toward the aquifer. This is what groundwater pumping did to the Santa Cruz River. It dried up the Santa Cruz by lowering the level of the water table below the elevation of the river. Groundwater pumping literally sucked water from the river and produced horrible environmental consequences. First, of course, the flow in the river disappeared, as did water-dependent species. Then, the trees and shrubs died as groundwater pumping lowered the water table below the root zone of the vegetation.

In Arizona, groundwater pumping has dried up or degraded 90 percent of the state’s once perennial desert streams, rivers, and riparian habitats. Some marvelous habitat remains healthy but faces an uncertain future. For example, the San Pedro River is southeastern Arizona supports an estimated 390 species of birds (almost two-thirds of all species seen in North America). The area is so special that Birder’s Digest, the Nature Conservancy, the American Bird Conservancy, and the National Audubon Society have given the river special designation. However, the population of the city of Sierra Vista and Cochise County is exploding, and all of this growth is dependant on groundwater. Local politicians and developers fear that environmental issues may retard growth. It is possible that the San Pedro River will suffer the same fate as the Santa Cruz.

Not surprisingly, some developers maintain that groundwater pumping has not caused the lower flow levels in the San Pedro River. To be sure, there will always be a problem of determining the causal relationship between groundwater pumping and environmental degradation. Scientific uncertainty attends many disputes over the impact of pumping on a particular river or spring. Some of this debate is in good faith, an honest disagreement about what the evidence suggests and the computer models predict. Other positions seem animated by gross self-interest. With so much money at stake, developers pay consultants handsome fees to help obtain lucrative permits to pump.

In considering other examples of environmental problems caused by groundwater pumping, the first thing to note is that the impact of groundwater pumping on the environment is not confined to the arid West. Consider Florida. One of the wettest states in the country, with an average of more than 54 inches of rain a year, Florida has always had a problem with water. Historically, the problem was too much water. In a state surrounded on three sides by ocean and with enormous aquifers and extremely high water tables, the problem was how to get rid of the water. Although that story is relatively well known, another version of Florida’s water woes is not.

Florida’s population jumped from 2.7 million people in 1950 to 16 million in 2000, making Florida the fourth most populous state. A region that is experiencing particularly explosive growth is Tampa Bay. In search of additional supplies during the 1970s, Tampa Bay Water (the local water utility) purchased large tracts of rural areas in adjoining counties and drilled a huge number of wells. By 1996, groundwater withdrawal had risen to approximately 255 million gallons per day, a 400 percent increase over 1960 levels. When lakes and ponds began to dry up–one study found that fewer than 10 of 153 lakes in the region were healthy–Tampa Bay Water knew it had a public relations disaster on its hands. Homeowners who had bought lakefront property only to watch it dry up were not amused. In response, Tampa Bay Water began to dump hundreds of thousands of gallons of water per day into the dry lakebeds. Where did Tampa Bay Water get this additional water? From groundwater pumping. Yet this additional groundwater would inevitably drain back into the ground in search of the water table. It was like trying to keep water in a colander.

Tampa Bay is not the only area where officials have tried to mask the consequences of groundwater pumping. In San Antonio, Texas, Paseo del Rio, or River Walk, has become the city’s most popular tourist attraction. A 2.5-mile section of the San Antonio River that flows through the heart of downtown, River Walk anchors a $3.5 billion-per-year tourist industry. Most tourists would be surprised to learn that the river they enjoy is the creation of dams, floodgates, and groundwater pumped from the Edwards Aquifer and dumped into the San Antonio River above River Walk. The San Antonio River was once navigable though the River Walk stretch, but it dried up because of groundwater pumping. In short, the city of San Antonio pumps millions of gallons a day of groundwater into the river in order to create an economically useful fiction. As San Antonio has continued to expand, the San Antonio Water System began to search for new sources of water and to look for ways to reuse existing supplies. In 2000, the system began to dump treated municipal effluent into River Walk as a substitute for groundwater. The water creating the illusion of a real river is still groundwater, but it has been used before.

We must increase water rates so that all users pay the replacement value of the water.

Americans use groundwater to grow all kinds of things, even when there is no need to do so. Until rather recently, many U.S. farms were “dryland” farmed, meaning that the farmers had no irrigation system. However, Americans’ love affair with processed foods caused some potato farmers to shift from dryland to irrigation farming. The problem with dryland potatoes is that their size, shape, and texture depend heavily on seasonal weather patterns. During the growing season, potatoes need constant moisture or they will have knobs and odd shapes. A misshapen or knobby potato is perfectly edible, but it is not an acceptable potato for the fast-food industry. In 1988, McDonald’s began to offer consumers “super-sized” meals with larger portions of french fries served in rectangular boxes with flat bottoms. Only potatoes grown through irrigation produced a uniform length fry that would jut out of the super-size box just the right amount so that the consumer could grasp the potato between index finger and thumb and dip it in ketchup. The desire for the perfect fry is felt by the trout in north central Minnesota, where potato farms rely on groundwater that is very closely connected hydrologically to blue-ribbon trout streams. Increased pumping to support additional potato production threatens the survival of trout.

For a final example, consider the country’s newfound fascination with bottled water. Sixty percent of Americans drink bottled water, which is now the fastest growing product among the top 50 supermarket categories. Between 1978 and 2001, consumption rose 1,300 percent to 5.4 billion gallons, or about 43 billion 16-ounce bottles. A major beneficiary of the bottled-water craze is the Perrier Group of America. Most consumers know Perrier as the importer of green bottles of spring water from France. But Perrier also sells bottled spring water under 14 other brand names, including Arrowhead, Calistoga, Deer Park, Zephyrhills, Poland Spring, Ozarka, and Ice Mountain. Indeed, Perrier has become the largest U.S. bottler of water (ahead of Pepsi and Coke) with a 32 percent market share. To supply its needs in the United States, Perrier relies on approximately 50 locations around the country, yet it must relentlessly search for new sources to satisfy the growing demand.

One place where Perrier looked was the Mecan River in Wisconsin. A blue-ribbon trout stream, the Mecan has been carefully protected by the state. Beginning in the 1950s, Wisconsin acquired more than 6,000 acres on the Mecan and surrounding tributaries. In 1999, Perrier proposed building a bottling plant and drilling wells on land near Mecan Springs. Environmental groups were aghast at the prospect, for they knew that the cool, underground spring water was critical to the fragile ecology of the river. But under Wisconsin law, the state could not halt Perrier’s commercial operation unless the pumping would interfere with the municipal water supply, and it would not. Perrier proposed to pump 720,000 gallons per day from a well located immediately adjacent to the springs. In the end, Perrier decided not to proceed with this plant, in part because of substantial opposition from local residents. However, the problem of the impact of pumping spring water has not gone away. It has simply changed locations. In 2001 and 2002, Perrier opened bottling plants in Tennessee, Michigan, and California.

The urgent need for reform

In the United States, the impact of groundwater pumping on the environment is an example of what biologist Garrett Harden called “the tragedy of the commons.” The legal rules governing groundwater use encourage exploitation of the resource: They reward rational economic individuals by permitting them to pump enormous quantities of groundwater, regardless of the environmental impact. Most states have failed to eliminate the gap between law and science. In lieu of legal reform, Americans have shown limitless ingenuity in devising technological fixes for water supply problems. These so-called solutions have altered the hydrologic cycle in order to sustain existing usage.

As our water use spirals upward, we must begin to rethink the economic structure by which we value (and usually undervalue) our water resources. At the same time, we must act to protect our rivers, springs, wetlands, lakes, and estuaries from groundwater pumping. There is considerable urgency. Because groundwater moves so slowly, it may take years or decades of groundwater pumping before the effect on the environment is apparent. The hidden tragedy and irremediable fact is that groundwater pumping that has already occurred will cause environmental damage in the future.

We must reform the system. A cure will not come quickly or easily, but nature has enormous regenerative capacity. The solution involves charting a new course for the future based on wise policies, then making a commitment to stay the course. It can be done. In the process, state and local governments must play a critical role.

To control the impact of groundwater pumping on the environment, we must combine a command-and-control model of government rules and regulations with the market forces of transferable rights and price incentives. Any meaningful reform must do two things: protect the rights of existing users by creating quantified water rights that are transferable and therefore valuable; and break free of the relentless cycle of increasing use by placing restrictions on individual freedom to pump groundwater.

States should foster a market in water rights by allowing the easy transferability of rights from existing users to newcomers. Enormous quantities of groundwater are used for extremely low-value economic activities. State law must facilitate the movement of water from these uses to higher-value ones by establishing a water rights market as the mechanism for accomplishing this shift. But water markets are not the only solution.

Government rules and regulations deserve a prominent place in our reform efforts as we attempt to protect the environment. The states should undertake a number of very specific reforms. First, states should carefully craft water conservation standards. A water conservation program seems, intuitively, like a good idea: Let’s save water. However, the experience of some western states with conservation standards sends a mixed message. If the states attempt to impose elaborate and detailed conservation standards, the regulated groups will fight tooth and nail over every sentence in the proposed regulation. This process can consume enormous amounts of time, energy, and money. The lesson for states is that it is better to embrace simple conservation standards that are easy to administer and implement. They are likely to have the most practical effect in terms of actually saving water and will avoid prolonged political struggle. In other words, it is easier to pick low-hanging fruit.

Congress should create a program to reward states that protect their environments from groundwater pumping.

Second, states should establish minimum stream flows and protect those flows from pumping of hydrologically connected groundwater. Through a combination of statutes, judicial decisions, and administrative rules, the state of Washington has developed a system that other states should emulate. The legislature authorized the State Department of Ecology to establish minimum water levels for streams and lakes to protect fish, game, other wildlife resources, and recreational and esthetic values. The minimum levels become appropriations within the prior appropriation system and offer protection against subsequent groundwater pumping.

Third, states should prohibit the drilling of new wells in areas that are hydrologically connected to surface flows. Generally speaking, the farther a well is from a watercourse, the less significant the impact of groundwater pumping from that well will be. States have two options for this problem: They can make the ban on wells near watercourses turn on a hydrologic analysis of the particular region, or they can use a bright-line rule that simply prohibits drilling wells within, for example, a mile of the river. Oregon has moved in this direction.

Fourth, states should impose an extraction tax on water pumped from any well within a certain distance of a river, spring, or lake. This tax would have two benefits: It would encourage existing pumpers to conserve water, and it would create an incentive for new pumpers to locate wells farther away from watercourses.

Fifth, states should require any new pumper to offset or mitigate the impact on the environment. It makes no sense to allow developers to drill new wells in an aquifer already under stress. Arizona has a mitigation program that requires developers to demonstrate an “assured water supply.” One way to do so is for the developer to purchase and retire agricultural rights.

Sixth, states, especially through local governments, should use financial incentives as a significant part of water policy. Quite simply, we are not paying the true cost of water. When homeowners or businesses receive a monthly water bill from the utility, that bill normally includes only the extraction costs of drilling the wells, the energy costs of pumping the water, the infrastructure costs of a distribution and storage system, and the administrative costs of the water department or company. Water rates, with rare exceptions, do not include a commodity charge for the water itself. The water is free.

Even though water is a scarce commodity, most Americans have not yet faced the condition that economists call scarcity, which occurs when people alter their consumption patterns in response to price increases. Our habits of water use will not change until the cost of water rises sufficiently to force an alteration. Therefore, we must increase water rates so that all users pay the replacement value of the water, which includes not just the cost of drilling a new well but also the cost of retiring an existing user’s well.

Economists agree that significant price increases would create incentives for all users to conserve. All farmers, homeowners, businesses, or industrial users could then decide which uses of water to continue and which to curtail. Rate increases would encourage the elimination of marginal economic activities and the movement of water toward more productive uses.

Seventh, whenever a water rights transfer occurs, the states should require that a small percentage of the water be dedicated for environmental purposes. States should not get too greedy with this environmental dedication, however, or it will be self-defeating. The prospective parties to a transfer will, of course, consider the economic consequence of the dedication on their proposed transfer. If the dedication is too onerous, the sale or lease will not take place. But a modest dedication program has great potential for environmental restoration.

Eighth, both the state and federal governments should commit resources to purchasing and retiring groundwater rights to protect critical watersheds and habitat. Some might argue that the federal government should preempt the area, given how poor a job the states have done. However, Congress has historically deferred to the states with respect to water laws. Proposals for federal regulation of groundwater will give rise to a chorus of howls from states’ rights advocates, especially those in the West, who, as author Wallace Stegner once observed, conceive the role of the federal government as “Get out! And give us more money!”

Congress certainly has constitutional authority to impose federal regulations on groundwater pumpers, yet there are two good reasons why it should not do so. First, it would provoke a bruising political battle. The political capital expended to win that fight could be better spent elsewhere. Second, the impact of groundwater pumping on the environment is nuanced and site-specific, depending enormously on the particular hydrologic characteristics of an aquifer. Imposing a uniform federal template on the nation is likely to exclude some pumping that should be regulated and to include some pumping that poses no serious risk of harm. Offering the carrot of federal funds is a far better approach than wielding the stick of federal regulation. Under its taxing and spending power, Congress should create a program funded by federal tax dollars to reward states that protect their environments from groundwater pumping (a gentle form of coercion). A host of federal programs, such as highway funding, give the states money but attach conditions.

The impact of groundwater pumping on the environment is enormous. And it is getting worse. As the drought that is gripping the country continues, cities, farmers, and individual homeowners are scrambling in search of additional water supplies. They have often focused on groundwater; indeed, well-drilling businesses around the country are booming. The drought has prompted the media to pay remarkable attention to water issues. In the summer of 2002, the New York Times ran a four-part front-page series, and U.S. News & World Report, Newsweek, and National Geographic ran cover stories. Yet none of these stories, or any others to my knowledge, mentioned that groundwater pumping has environmental consequences.

Recommended Reading

  • William M. Alley, Thomas E. Reilly, and O. Lehn Franke, Sustainability of Ground-Water Resources (U.S. Geological Survey, circular 1186, Denver, Colo.: 1999).
  • Robert Glennon and Thomas Maddock, III, “The Concept of Capture: The Hydrology and Law of Stream/Aquifer Interactions,” in Proceedings of the Rocky Mountain Mineral Law Institute (1997): vol. 43, 22-1 to 22-89.
  • Robert Glennon and Thomas Maddock, III, “In Search of Subflow: Arizona’s Futile Effort to Separate Groundwater From Surface Water,” Arizona Law Review 36 (1994): 567­610.
  • Wayne B. Solley, Robert R. Pierce, and Howard A. Pearlman, Estimated Use of Water in the United States (U.S. Geological Survey, circular 1200, Denver, Colo.: 1998).
  • Thomas C. Winter, Judson H. Harvey, O. Lehn Franke, and William M. Alley, Ground Water and Surface Water: A Single Resource (U.S. Geological Survey, circular 1139, Denver, Colo.: 1999).
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Cite this Article

Glennon, Robert. “The Perils of Groundwater Pumping.” Issues in Science and Technology 19, no. 1 (Fall 2002).

Vol. XIX, No. 1, Fall 2002