Water Policy in the American West

I

Introduction

Water Policy in the American West, methods of regulating water in the western United States. These methods include traditions, laws, and technologies. Over the past two centuries, water policy in the western United States has gradually shifted from regulating water for agricultural purposes, such as irrigation, to regulating it for urban uses. In the 20th century, water policy has moved from a primarily local and regional concern to a national one, as the federal government has taken a more active role in formulating and executing water policy.

Water policy has played a more prominent role in the American West than in other areas of the United States because of the region’s climate. The western half of the United States is a mostly dry area that differs dramatically from the eastern United States. As early as 1878 the explorer and scientist John Wesley Powell called public attention to the special character of the land that lay west of the Mississippi River.

In his Report on the Lands of the Arid Region of the United States (1878), Powell observed that most of the land lying west of the 100th meridian of longitude receives less than 20 inches of precipitation annually. (Precipitation is a general term that refers to both rain and melting snow.) As Powell explained, the 20-inch line that runs north-south through the center of Texas, Oklahoma, Kansas, Nebraska, and the Dakotas is important because it relates to the land’s ability to support agriculture. East of the 20-inch line farmers can usually grow crops simply by relying on normal precipitation. But west of this line it is often difficult, and in many areas impossible, to cultivate crops without applying additional water to the soil through the process known as irrigation.

In this article, the American West is defined to encompass land in the United States between approximately the 100th meridian and the Pacific Coast. Alaska and Hawaii, with their own distinctive environments and histories of water use, will not be discussed.

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II

Water Supply

Water supplies fall into two basic categories: surface water and groundwater. Surface water is the water that exists in streams, rivers, or lakes. When rain falls on the ground or when snow melts, much of this precipitation drains across the surface of the earth and collects in ravines, streams, and creeks. Gradually these smaller waterways join together and form rivers. A group of rivers and the streams that feed into them make up a river basin, also known as a watershed. A river basin denotes all land through which a particular river and its tributaries flow. With the exception of a few geographical areas, such as the Great Basin, the ultimate destination of surface water is an ocean. Most people think of surface water when they hear the term water resources, and the history section of this article primarily focuses on this type of water supply.

However, when precipitation falls to the ground, not all the water runs into rivers as surface flow. Some precipitation becomes groundwater after seeping down into the earth and collecting within underground reservoirs called aquifers. Some aquifers amass underground seepage during thousands, sometimes millions, of years and accumulate huge quantities of water. In many parts of the West, aquifers are important components of the regional water supply. This is especially true in the Great Plains east of the Rocky Mountains, where many farms pump water to use for irrigation from a vast underground reservoir known as the Ogallala Aquifer.

III

Feast or Famine

Throughout most of the American West, precipitation is not evenly distributed over the landscape during the course of the year. Sometimes there is abundant water, even too much water, causing floods. But then there may be long periods with little or no precipitation. Much of the water in the region comes in the form of snow that accumulates in the mountains; upon melting, this water is released into rivers during a few months in the spring and early summer. But after the spring floods pass, many Western rivers and streams practically run dry during the late summer and fall. At other times, billions of gallons of water might be dumped on parts of the West during torrential rainstorms that last for a few days or weeks. However, such heavy storms occur infrequently and may not arise for several years in a row. When this happens, precipitation for the year can fall far below the annual average causing a sharp drop in the available water supply.

It is the feast or famine character of water supply in the West that distinguishes it from the eastern United States. It also illuminates why water control in the West is of such special importance: The western half of the United States contains an abundance of land but suffers from a relative shortage of water. This water, in its natural state, is often confined to limited areas of land and is available during only certain times of the year. In strictly economic terms, land devoid of water is not worth much. Early on, people in the West began to look for ways to store and transport water in order to increase the amount of usable land and thereby increase its value. As a result, water control became a key factor in the region’s economic development.

In an effort to utilize and conserve water, two major types of dams were built—diversion dams and storage dams. Diversion dams are small structures designed to raise the elevation of a river so that gravity can be used to direct, or divert, water out of a streambed and into a constructed canal or other artificial waterway. Diversion dams often channel away only a portion of a river’s flow, allowing the rest to pass downstream.

In contrast, storage dams usually are much larger structures erected to hold back or impound water in reservoirs for long periods of time. Because of their size, diversion dams are easier to construct. Storage dams, however, possess special economic significance because they can capture and store large seasonal floods. Later, when the natural flow of the river drops, the floodwaters captured in a reservoir can be released over a period of months or even years.

IV

Water Rights

Water rights is a legal concept that defines how water is distributed among various users within a river basin, state, or country. In the United States there are two basic systems of water rights: the riparian doctrine and the doctrine of appropriation.

Riparian doctrine holds that water rights should be allocated equally among all people who own land adjoining a river. In its strictest form, no one owning land along a riverbank governed by the riparian doctrine would be allowed to significantly reduce the river flow. Over the past century, the riparian doctrine has been modified in the United States by court rulings to allow some diversions of water that change the amount of flow carried by the river. Nonetheless, the riparian doctrine still represents a way to allocate water rights so that all riparian users have similar rights to the water based upon land ownership.

Appropriated rights do not confer any special privilege to people who own land along a riverbank. Instead, the doctrine of appropriated rights considers water flowing in a stream to be a commodity that can be taken—that is, appropriated—and used elsewhere, even hundreds of miles away. Appropriated rights are usually allocated on a “first in time, first in right” basis. In other words, the first people to take water out of a river obtain a primary right that supersedes the rights of everyone who later diverts water from the same stream.

During times of drought, the distinction between people with primary water rights and those with secondary rights can become extremely important. The people with primary rights could appropriate the entire flow of the river, leaving nothing for those with secondary rights. The doctrine of appropriated rights puts some constraints on water users: First, they must use the water for an economically beneficial use, such as irrigating crops; in addition, they must continue to use it year after year, or they will lose it.

The two doctrines of water rights—riparian and appropriated—inherently conflict with each other. In its most basic form, the riparian doctrine does not allow users to significantly diminish the flow of water in a river. In contrast, the doctrine of appropriated rights allows a user to do so. In addition, the doctrine of appropriated rights requires that the water be used for a beneficial purpose, whereas the riparian doctrine is based on land ownership (owning land next to the river), not on how the water is used.

Several Western states including Colorado, Arizona, Wyoming, and Utah, have acknowledged this conflict and have specifically denied any legal standing to the riparian system. But other Western states—notably those on the Pacific Coast, where natural precipitation can be abundant in certain areas—have recognized the validity of riparian rights under certain circumstances. California is best known for attempting to recognize both riparian and appropriated water rights. Not coincidentally, California is notorious for the lengthy legal battles among competing groups of water users seeking to establish and protect their legal rights.

No single government agency or individual is responsible for defining how water is used. Instead, many different groups—both private and governmental—have shaped water policy, including local, state, and federal agencies. Sometimes these groups agree and act together to achieve a common goal, but often they disagree, and a resolution has to be worked out through court cases, government action, or negotiation. For example, agricultural and urban interests in a state might disagree on specific issues related to water distribution, but they might act together when lobbying for federal money to fund water projects. The interaction of these groups has created a multifaceted policy, which does not adhere to a single vision of how water should be used.

Changes to water policies occur slowly because water rights are a form of property, and changes to property rights are difficult to make within the U.S. legal system. It is possible for water policy to evolve in response to social and political pressure, but such changes must occur within a legal environment that places great importance on protecting property rights.

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