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Climate Change Heating Up Water Wars: Clashes Across the US

February 23, 2023

The following alert is included in Insights 2023, a collection of articles and videos addressing important emerging legal issues in the year ahead.

Water wars—fought for centuries in the American West—are now raging across the country, as states and water users battle over diminishing supplies.

In 2022, 85% of the nation suffered abnormally dry or drought conditions. Climate change is at least part of the reason, raising the specter of even worse shortages in the future. Not only are droughts more frequent and more severe, but higher temperatures are also reducing snow fall, increasing evaporation, and generating greater demand even as supplies decline.

Almost no part of the country has been spared in recent years. California endured the driest three years in its recorded history from 2020-22.

Areas of the South, Southeast, Midwest, and High Plains also were parched last year. Following decades of limited rainfall, the two major reservoirs on the Colorado River—the lifeblood of the Southwest—are approaching “dead pool” levels, which would cut off both water availability and hydroelectric production. Scientists estimate that the West has not been this dry in more than 1,200 years.

When tensions between states spill over, the disputes fall under the exclusive jurisdiction of the US Supreme Court. Mississippi has sued Tennessee, arguing before the Court that the city of Memphis was stealing its groundwater because the city’s wells were causing groundwater under Mississippi to flow across the border into Tennessee. And Florida sued Georgia, alleging that Georgia’s rapacious thirst for water dramatically reduced Apalachicola River flows, harming both the river’s ecosystem and Florida’s oyster fisheries in Apalachicola Bay.

Even voluntary agreements, which were once successful in resolving interstate water disputes, are failing to avert new lawsuits in the face of droughts and other shortages. Since the early 20th century, states have agreed to Congressionally approved “interstate compacts” to avoid the time, cost, and risk of litigation. These compacts spell out how much water each state can divert from shared rivers and resolve other disagreements. But when shortages hit, states often find themselves unable to agree on exactly what the compacts require, and they end up before the Supreme Court after all. In the last decade, the Supreme Court has had to resolve disputes over both the Yellowstone River Compact (Montana, North Dakota, and Wyoming) and the Pecos River Compact (New Mexico and Texas). Recently, the dwindling waters of the Colorado River have generated heated disputes over the meaning of the Colorado River Compact, which has guided river operations for a century. It remains to be seen whether that compact also comes under the scrutiny of the justices.

Shortages have prompted other kinds of litigation as well. As climate change reduces surface supplies, users often turn to groundwater. Overpumping can result in falling groundwater tables and various associated problems, including surface subsidence. So, not surprisingly, groundwater adjudications, in which courts resolve disputes over groundwater withdrawals, are also on the rise. California hoped to avoid such lawsuits by passing a law in 2014 that requires local agencies to sustainably manage the state’s groundwater basins, but the administration of that law has already led to six new groundwater lawsuits, and far more are likely. Water shortages have also led Indian tribes to file claims to water as a matter of treaty rights and federal law. The Supreme Court recently agreed to hear a case involving the Navajo Nation’s claim to Colorado River water. Finally, environmental organizations and governmental agencies are bringing lawsuits to ensure that water users leave sufficient water in rivers and streams to protect freshwater ecosystems in the face of climate change.

In short, climate change is driving severe drought in more and more parts of the United States. In response, water users and environmental advocates are turning to the courts to claim whatever they can of the shrinking supplies. The disputes—some of which involve hundreds of parties—are complex enough to make even negotiating voluntary settlements a long and expensive process. Parties who get out ahead of these issues and focus on problem- solving can better control their fate and reach favorable resolutions.

This memorandum is a summary for general information and discussion only and may be considered an advertisement for certain purposes. It is not a full analysis of the matters presented, may not be relied upon as legal advice, and does not purport to represent the views of our clients or the Firm. Buzz Thompson, an O’Melveny of counsel licensed to practice law in California, and Heather Welles, an O’Melveny counsel licensed to practice law in California, contributed to the content of this newsletter. The views expressed in this newsletter are the views of the authors except as otherwise noted.

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