Chapter 11 INTERJURISDICTIONAL GROUNDWATER ALLOCATION

• Jurisdiction: United States

Water Law Institute
Chapter 11

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INTERJURISDICTIONAL GROUNDWATER ALLOCATION
Christine A. Klein Cone, Wagner, Nugent, Hazouri & Roth Professor of Law University of Florida Levin College of Law Gainesville, FL

CHRISTINE KLEIN is the Cone, Wagner, Nugent, Hazouri & Roth Professor of Law at the University of Florida Levin College of Law. She began her legal career as a water rights litigator in the Colorado Office of the Attorney General. In 1995, Klein joined the faculty of Michigan State University College of Law and directed its environmental law certificate program. In 2003, she moved to the faculty of the University of Florida, where she teaches and writes in the areas of water law, natural resources law, and property law. Her work includes more than thirty academic articles and has been cited in judicial and administrative opinions at both the federal and state levels. She is also the author of several books: Property Law: Cases, Problems, and Skills (Aspen Publishers 2d ed. 2020), Natural Resources Law: A Place-Based Book of Problems and Cases (Aspen Publishers 4th ed. 2018) (with Cheever, Birdsong, Klass & Biber), and Mississippi River Tragedies: A Century of Unnatural Disaster (NYU Press, 2014) (with Sandra Zellmer). Klein has served on two committees of the National Academy of Sciences, National Research Council, that studied sustainable water and environmental management in the California Bay-Delta, and she is a member scholar of the Center for Progressive Reform, based in Washington, D.C. She received a B.A. from Middlebury College in Vermont, a J.D. from the University of Colorado Law School, and an LL.M. from Columbia University Law School.

Introduction

Although groundwater represents only about 1.7% of all Earth's water, it comprises more than 30% of our planet's supply of fresh, unfrozen water.¹ Despite groundwater's critical importance, we lacked the technological capacity to extract it in significant quantities until the invention of the high-speed centrifugal pump in 1937 and subsequent mid-twentieth century innovations.² By that time, numerous water doctrines had become firmly rooted in the law, focusing primarily on surface water and giving groundwater scant, if any, attention.

This chronology poses significant challenges for the interjurisdictional allocation of groundwater. The relevant law took root about half a century before the advent of large-scale groundwater use: In 1907, the Court announced the equitable apportionment doctrine in Kansas v. Colorado;³ in 1908, the Court articulated the federal reserved water rights doctrine in Winters v. United States,⁴ and in 1925, the La Plata River Compact was the first interstate water agreement to gain full approval.⁵ Since that time, the law has been scrambling to incorporate groundwater into interjurisdictional allocations.

Part I discusses the allocation of water among states. It first examines the extent to which groundwater has been included in allocations of surface streams by compact or equitable apportionment. Next, it considers the pending Supreme Court litigation in Mississippi v.

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Tennessee, which raises the issue of whether groundwater aquifers can be the proper subject of apportionment, independent of the allocation of any particular river or stream.

Part II turns to the federal reserved rights doctrine, which functions as a mechanism to allocate water rights between federal and state users. This Part first explains the extent to which the Court has been willing to regulate groundwater uses that threaten surface reserved rights. Next, it discusses whether groundwater can be the proper subject of a reserved right itself, focusing on the Ninth Circuit's 2017 decision in Agua Caliente Band of Cahuilla Indians.

Finally, Part III places this paper into a broader context. It considers a phenomenon that I have labelled "groundwater exceptionalism,"⁶ under which the law has treated groundwater differently, and often more leniently, than surface water. Viewed from this perspective, the challenge of integrating groundwater into interjurisdictional allocations reflects the difficulty of incorporating groundwater into numerous other water law doctrines, including the prior appropriation doctrine, the riparianism doctrine, and the federal Clean Water Act. As a broad pattern across doctrines, typically the law first regulates tributary groundwater that can impact surface streams, and then later addresses more complicated questions of how to allocate, reserve, or protect groundwater for its own sake.

I. Interstate Allocation of Groundwater

Three primary methods have been used to allocate transboundary waters among the states: (1) interstate compacts, (2) equitable apportionment, and (3) congressional apportionment (although the latter method has been used rarely).⁷ Most of the early agreements confined their focus to the allocation of the right to use interstate surface waters, but disputes over groundwater have become more frequent over time.

A. Interstate Compacts

1. The doctrine

To resolve disputes over water, the states can come to an agreement known as an "interstate compact," which becomes law upon ratification by Congress under the authority provided by

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Article I of the Constitution.⁸ The U.S. Supreme Court has indicated its preference for this method of interstate allocation.⁹

2. Regulating tributary groundwater that threatens surface allocations

To date, there are twenty-three water apportionment compacts. Only four of these agreements mention groundwater, generally including some groundwater in the allocation only if it is tributary or causes measurable depletions to the surface stream that is the subject of the compact.¹⁰

As groundwater pumping increased dramatically over time, thousands of new wells threatened to interfere with some states' compact allocations of surface water. The injured states called upon the Supreme Court to determine whether existing compacts impliedly authorized the regulation of well pumping, even if the agreements failed to specifically account for "groundwater." To date, the Court has interpreted five compacts that allocate, respectively, the (1) Rio Grande River, (2) Republican River, (3) Arkansas River, (4) Pecos River, and (5) Yellowstone River. In each case, the Court held that the subject compact impliedly restricts groundwater use that depletes apportioned surface streams.¹¹ Moreover, the Court has approved new remedies to deter future compact breaches through groundwater use, including shifting the burden of proof, awarding damages plus post-judgment interest, and requiring in-kind damage payments of water.¹²

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3. Allocating aquifers independently of surface waters

To date, no interstate compact has focused solely on the allocation of groundwater, apart from surface watercourses.

B. Equitable Apportionment

1. The doctrine

If the states cannot agree on a compact to resolve interstate disputes, they can petition the U.S. Supreme Court to step in, although it is a reluctant arbiter.¹³ The Court has original jurisdiction over interstate water disputes. It has developed a body of federal common law known as "equitable apportionment" to resolve such disputes. Under that doctrine, the Court awards each competing state an "equality of right" to use the disputed watercourse, but it has made clear that this does not necessarily mean that each state is entitled to use an equal volume of water.¹⁴ As of 2021, the Court issued only four equitable apportionment decrees, which allocated the right to use the following rivers: (1) Delaware River, (2) Gila River, (3) Laramie River, and (4) North Platte River.¹⁵ In addition, the Court has dismissed seven other petitions for apportionment on ripeness and other grounds: (1) Arkansas River, (2) Connecticut River, (3) Walla Walla River, (4) Colorado River, (5) Vermejo River, (6) Catawba River, and (7) the Apalachicola-Chattahoochee-Flint River Basin.¹⁶

2. Regulating tributary groundwater that threatens surface allocations

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Each of the above-described petitions for apportionment focused primarily on surface waters flowing as interstate rivers. As one treatise explains, "[A]lthough groundwater was, or perhaps was, involved in [a few cases], the Court has not explicitly extended the equitable apportionment doctrine to interstate groundwater, though it might do so on proper facts."¹⁷ To date, the Court has indicated its potential willingness to regulate groundwater withdrawals in its apportionment of interstate rivers, but only if pumping threatens to cause "substantial depletion" to surface flows or significant injury to the state petitioner.¹⁸ More recently, in Florida v. Georgia, Florida sought an equitable apportionment of the waters of the Apalachicola-Chattahoochee-Flint River Basin, including "groundwater, rivers, streams, creeks, draws, and drainages" and all waters "hydrologically" connected to the named surface streams.¹⁹ Although the Supreme Court ultimately dismissed Florida's petition for failure to demonstrate sufficient harm to justify an apportionment, the Court did not question the Special Master's broad inclusion of groundwater pumping in his analysis of the alleged harm suffered by Florida.²⁰

3. Allocating aquifers independently of surface waters--Mississippi v. Tennessee

An original action argued before the U.S. Supreme Court on October 4, 2021, raises the question of whether interstate aquifers can be the proper subject of apportionment, apart from any...