In her questioning of Elena Kagan yesterday, Sen. Dianne Feinstein (D-CA) asked about the degree to which courts should defer to agency constructions of statutes, pointing to a 2006 Supreme Court decision regarding the Clean Water Act (CWA) that left intermittent seasonal streams unprotected.

Kagan told Senator Feinstein she did not know of the specific decision and, instead, explained the general principles of judicial deference to agency constructions of statutes passed by Congress.  In doing so, she correctly referred to the Court’s decision in Chevron U.S.A., Inc. v. Natural Resources Defense Council, 467 U.S. 837 (1984).

It is unfortunate that Justice Scalia was not there to answer Senator Feinstein’s question Not only is he an authority on administrative law, he wrote the plurality opinion in Rapanos v. United States, 547 U.S. 715 (2006), the decision that Senator Feinstein criticized. As both Scalia and Kagan know, the first part of the Chevron analysis looks at whether the agency’s interpretation is “based on a permissible construction of the statute.”

Rapanos involved the scope of the term “navigable waters” in the Clean Water Act.  The Act defines “navigable waters” as “the waters of the United States, including the territorial seas.”  The Corps of Engineers issued regulations to include not only traditional interstate waters that are actually navigable, like the Potomac River, but all interstate waters and wetlands.  Not content with this broad scope, the Corps also included “[a]ll other waters such as intrastate lakes, rivers, streams (including intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds, the use, degradation or destruction of which could affect interstate or foreign commerce.”  Still not content, the Corps interpreted its regulations to include “ephemeral streams” and “drainage ditches” so long as they had a “perceptible high water mark.”

Anyone who doesn’t see that the Corps’ definition extends the reach of the CWA to all places where water is on the ground, no matter how small, shallow, or intermittent, needs to get out more often.  But, the water grab did not stop there.  Federal courts applied the Corps’ definition to specific “bodies” of water, including the “washes and arroyos” of an “arid development site, in the middle of the Sonoran desert through which “water courses . . . during periods of heavy rain.”

In Rapanos, the Court held that, while the “waters of the United States” were not just those that were navigable in fact, the term “waters” could not bear the weight that the Corps wanted to put on it either.  More particularly, the possible definitions of “waters” don’t include “channels through which water flows intermittently or ephemerally, or channels that periodically provide drainage for rainfall.”  By including all of the intermittent and non-navigable waters that it did within the scope of its regulatory powers, the Court said that the Corps “stretched the term ‘waters of the United States’ beyond parody.”  In other words, the Corps’ interpretation was not “based on a permissible construction of the statute.”

The Corps’ interpretation also intruded into the traditional power of the states of their lands and waters.  In addition, it “stretche[d] the outer limits of Congress’s commerce powers.”

Justice Scalia wrote for a plurality that included Chief Justice Roberts and Justices Thomas and Alito.  Justice Kennedy concurred in the judgment, reasoning that a water or wetland can be part of the “navigable waters” if it has a “significant nexus” to waters that are or can reasonably be made to be navigable in fact.

The point for Senator Feinstein is that Congress included language in the statute defining – and limiting – the term “navigable waters.”  By defining that term, Congress limited the reach of the Corps of Engineers.  If Senator Feinstein wants someone to protect the intermittent seasonal streams of California, she might try to amend the statute. Better yet, she might look to the State of California to do that.