Environmental law is of relatively recent vintage. Most of its significant principles date from the 1960s or later, with a few notable exceptions. The latter category includes the public trust doctrine. As the name suggests, the doctrine is generally taken to mean that a state must act as “trustee” of certain natural resources, particularly the navigable waters of the state, and manage them for the trust beneficiaries—its people. The doctrine can be traced back to ancient Roman law. The “Institutes of Justinian,” compiled in the Sixth Century A.D., provided:
“By the law of nature these things are common to mankind—the air, running water, the sea, and consequently the shores of the sea. No one, therefore, is forbidden to approach the seashore, provided that he respects habitations, monuments, and buildings . . . .”
In this country, the United States Supreme Court recognized the doctrine in its 1892 decision in Illinois Central Railroad Co. v. Illinois, as detailed by Marquette Law School Dean Joseph Kearney in a 2004 article. The doctrine has since evolved into many different strains of varying strength primarily governed by state common law. Here in Wisconsin, it is rooted in the Article IX, § 1 of the state constitution, which itself borrowed heavily from the Northwest Ordinance of 1787. Over a hundred years ago, in Diana Shooting Club v. Husting, the Wisconsin Supreme Court described the doctrine as preserving to the people “full and free use of public waters,” and the Wisconsin Legislature has delegated the resulting regulatory authority to the Wisconsin Department of Natural Resources. As recently as 2011, in Lake Beulah Management District v. DNR, the Wisconsin Supreme Court expansively interpreted the doctrine as a valid basis for DNR to consider whether to grant, conditionally grant, or deny a high capacity well permit based on the well’s impact on other waters of the state.
However, several recent developments highlighted by a legislative hearing earlier this week seem to indicate that in Wisconsin, unlike other states, the relative strength of the public trust doctrine is ebbing.
Historically, the public’s water use rights were principally tied to commercial navigation, but over the years—at least until quite recently—the Wisconsin trend had been to aggressively extend public trust rights well beyond navigational purposes to “recreational enjoyment,” as the court recognized in 1952, and even “scenic beauty” as it held in 1972.
In other states, courts have further expanded the doctrine even beyond water. And in fact, the Illinois Central Court’s announcement of the doctrine was not specific to water; it referred instead to “property of a special character”—historically water, but theoretically implying applicability to other categories of resources held in trust for the public. In late 2015, for example, a Washington trial court ruled that the public trust doctrine required the state ecology department to protect the atmosphere from greenhouse gas pollution.
In Wisconsin, however, the trend has been in the other direction. First, in 2011, the Legislature enacted Wis. Stat. § 227.10(2m), which requires explicit statutory or regulatory authority for actions taken by administrative agencies, including the imposition of permit conditions. Arguably, this could prevent DNR from taking action based solely on the constitutionally- and common law-rooted public trust doctrine. In late 2015, a Wisconsin trial court relied on § 227.10(2m) to prevent DNR from imposing certain conditions in a high-capacity well permit.
In its 2013 opinion in Rock-Koshkonong Lake District v. DNR, the Wisconsin Supreme Court further scaled back the scope of the doctrine, tightly limiting it to a focus on navigable waters. The court found that DNR had improperly considered public trust-related impacts on wetlands adjacent to navigable waters. Instead, the court found, the public trust doctrine entails rights in sailing, rowing, canoeing, fishing, and the like on navigable waters.
Most recently, earlier this week the Wisconsin Legislature held a hearing on Assembly Bill 600. If enacted, AB 600 removes DNR’s authority to regulate certain categories of what currently could be considered navigable waters subject to the public trust doctrine, including (1) any area of a navigable water that was filled before January 1, 1975 and that has remained continuously filled since January 1, 1975; and (2) artificially created water bodies that are not hydrologically connected to natural navigable waterways and that do not discharge to natural navigable waterways. The bill also would require DNR to issue a general permit authorizing a riparian owner to remove 30 cubic yards of material from the bed of an inland lake adjacent to the riparian owner’s property and 100 cubic yards of material from the bed of outlying water, once each calendar year. DNR could previously have prevented such actions based on the public trust doctrine.
All of this controversy makes the common-law public trust doctrine one of the most intriguing parts of environmental law, a field increasingly dominated by statutes and regulations. The Wisconsin Supreme Court may have summed it up best by directing that “[w]hen considering actions that affect navigable waters in the state, one must start with the public trust doctrine . . . .” And yet, it’s not clear whether that is as true today as it once was.
 146 U.S. 387 (1892).
 156 Wis. 261, 145 N.W. 816, 820 (1914).
 2011 WI 54, ¶¶ 3-5, 335 Wis. 2d 47, 799 N.W.2d 73.
 Muench v. PSC, 261 Wis. 492, 499-508, 53 N.W.2d 514 (1952).
 Just v. Marinette County, 56 Wis. 2d 7, 18, 201 N.W.2d 761 (1972).
 Foster v. Wash. Dep’t of Ecology, Wash. Super. Ct. No. 14-2-25292-1 (Nov. 19, 2015).
 New Chester Dairy v. DNR, Case No. 2014CV1055 (Outagamie County Cir. Ct.).
 2013 WI 74, ¶¶ 86-90, 350 Wis. 2d 45, 833 N.W.2d 800.
 Hilton ex rel. Pages Homeowners’ Ass’n v. Dep’t of Natural Res., 2006 WI 84, ¶ 18, 293 Wis. 2d 1, 717 N.W.2d 166.