Contrasting Judicial Approaches to Environmental Law

These two cases involve the same copper smelters and the same pollution in the Appalachian forests near the Tennessee–Georgia border, yet the courts reached opposite conclusions on the remedy. The Tennessee Supreme Court denied the injunction, weighing the destruction of a major industry (employing 12,000 people, worth nearly $2,000,000) against the harm to individual small farms (valued at less than $1,000 aggregate). The U.S. Supreme Court granted the injunction, holding that Georgia's quasi-sovereign interest in its air and territory entitled it to protection more readily than a private party.

The critical difference is the identity and nature of the plaintiff. Private property owners must prove their case and convince the court that the balance of equities favours an injunction — a discretionary remedy. A state, by contrast, sues in its quasi-sovereign capacity, asserting an interest 'independent of and behind the titles of its citizens.' Justice Holmes held that a state is 'not lightly to be required to give up quasi-sovereign rights for pay,' and that the court has 'not quite the same freedom to balance the harm' as it would between private parties.

The contrast reveals a structural feature of environmental law: the identity of the plaintiff can determine the availability of relief. States, as quasi-sovereigns, may obtain injunctions that private individuals cannot — not because the pollution is different, but because the legal interest being protected is different. This principle continues to shape modern environmental litigation, including Massachusetts v. EPA (2007), where the Supreme Court relied on Tennessee Copper for state standing to challenge federal inaction on greenhouse gases.

Both cases involve interstate environmental harm mediated by the same man-made waterway system — the Chicago Area Waterway System connecting Lake Michigan to the Mississippi watershed. In 1906, Missouri sued to stop Chicago from discharging sewage into the Mississippi, alleging typhoid contamination. In 2011, the Great Lakes states sued to stop invasive Asian carp from using the same waterway to enter Lake Michigan. Despite the shared geography, the century between them produced different legal and scientific challenges.

The contrast illuminates the evolution of environmental jurisprudence. Missouri v. Illinois failed because the scientific evidence of causation was insufficient: experts disagreed on whether typhoid bacilli could survive the 357-mile, 8–18.5-day journey, and the court found the proof fell 'so far below the allegations' that the case could not proceed. Michigan v. Army Corps succeeded on the causation question — the Seventh Circuit found a 'substantial likelihood of harm' — but failed on the remedy question, because the extensive multi-agency regulatory effort to stop the carp 'diminished any role that equitable relief would otherwise play.'

The cases illustrate two recurring challenges in interstate environmental litigation. First, proving causation for invisible or diffuse environmental harm remains difficult, though modern ecological science has advanced considerably since 1906. Second, the relationship between judicial intervention and regulatory action has evolved: where no regulatory regime existed in 1906, by 2011 the existence of active regulatory efforts provided a basis for judicial deference — a form of 'prudential displacement' that falls short of formal legal displacement but has a similar practical effect. The court in Michigan explicitly reserved the right to revisit its conclusion if regulatory efforts faltered.

These four cases trace the development of regulatory takings doctrine from the foundational ad hoc balancing of Penn Central through the categorical rule of Lucas to the practical application of background principles in Palazzolo and Good. Together, they illustrate the two-track system that has emerged: the Penn Central multi-factor test for most regulations, and the Lucas per se rule for total takings.

Penn Central established that regulatory takings analysis is inherently ad hoc, weighing economic impact, interference with investment-backed expectations, and the character of the government action. Its finding that the Landmarks Law permitted reasonable beneficial use (the terminal continued operating and generated a reasonable return) and that transferable development rights (TDRs) mitigated the financial burden established the dominant framework for most takings claims. The case shows that where a regulation leaves the owner with reasonable beneficial use, no taking occurs — even if the most profitable use is prohibited.

Lucas created a categorical exception: when a regulation deprives land of all economically beneficial use, it is a per se taking — unless the proscribed use was not part of the owner's title under 'background principles' of nuisance and property law. This created both a clear rule (total loss = taking) and a demanding qualification (the state can avoid compensation by showing the use would be a nuisance). Palazzolo and Good show how these frameworks operate in practice. Palazzolo found no taking because the proposed development would be a public nuisance (ecological disaster to the pond) and the public trust doctrine limited title — both background principles meant the regulated use was never part of the title. Good found no taking because TDRs preserved residual economic value (defeating the Lucas per se claim) and the owner's investment expectations were not reasonable given the known regulatory climate (defeating the Penn Central claim).

The comparative study reveals several patterns. First, the Lucas per se rule is difficult to trigger in practice, because TDRs and residual value often prevent a finding of total economic loss. Second, the background principles test provides a powerful defense for environmental regulations: when nuisance law and the public trust doctrine prohibit the use, no compensation is required. Third, the timing and knowledge of the purchaser matters: those who acquire property with knowledge of regulatory constraints cannot claim reasonable investment-backed expectations. Fourth, TDR programs serve a dual function as both regulatory tools and factors that defeat takings claims.

These two cases bookend the development of California water law over 128 years. Irwin v. Phillips (1855) established the prior appropriation doctrine in California, displacing common law riparian rights — which would require streams to flow in their natural channels — in favour of the principle that the first user to divert water for beneficial use has priority. The court took judicial notice of the Gold Rush conditions, where water diversion was essential to mining and development. The 'first in time, first in right' principle became the dominant framework for water rights in the western United States.

National Audubon Society v. DWP (1983) integrated the prior appropriation system with the public trust doctrine, fundamentally reshaping California water law. The case arose when Los Angeles's diversion of virtually all the stream flow into Mono Lake caused the lake level to drop by one-third, converting an island into a peninsula and exposing gull rookeries to predators. The court held that the public trust doctrine protects navigable waters from harm caused by diversion of non-navigable tributaries, and that the state retains continuing supervisory authority over water allocations — even those previously granted — to protect public trust values.

The relationship between these cases reflects a fundamental tension in environmental law: the tension between economic development priorities (prior appropriation) and ecological protection (public trust). Irwin prioritised consumptive use, enabling the dewatering of streams for mining, agriculture, and urban development. Audubon restored a degree of ecological protection by requiring the state to consider public trust values before approving diversions and to reconsider past allocations. The court's insistence that the two systems 'must be integrated' — not treated as mutually exclusive — represents a sophisticated legal framework that respects both beneficial use and ecological integrity.

The trajectory from Irwin to Audubon illustrates a broader pattern in environmental law: legal doctrines that originally facilitated resource exploitation (prior appropriation, riparian rights, nuisance law) have been progressively modified and supplemented to address ecological concerns. The public trust doctrine, with its roots in Roman and English common law, has proven adaptable to modern environmental challenges, serving not only as a constraint on water diversions but also as a 'background principle' of property law that can defeat regulatory takings claims (as in Palazzolo v. State).