This week, Pacific Legal Foundation filed an amicus brief in Environmental Law Foundation v. State Water Resources Control Board. The brief, filed on behalf of the California Farm Bureau Federation, addresses the constitutional consequences of applying the public trust doctrine to groundwater extraction. The public trust doctrine is a common law principle that, in California, has been used successfully by environmental groups to require the state to take account of environmental values when making water allocation decisions. To date, the California courts have applied the doctrine only to activities having a direct and immediate effect on tidelands, non-tidal navigable waters, and tributaries to such waters. But the Environmental Law Foundation and its co-plaintiffs want the courts to extend the doctrine to groundwater extraction. PLF’s brief argues that, not only would such an expansion be unprecedented, it would raise serious constitutional questions under the due process and takings clauses. The Supreme Court has for long held that the Constitution binds the judiciary as much as the legislative and executive branches. Moreover, the Court has strongly suggested that judicial decision-making that deprives individuals of private property is unconstitutional. That assertion is significant here, because expanding the public trust doctrine to groundwater extraction would have the result of severely limiting what would otherwise be a protected right of use. Accordingly, PLF’s brief argues that the court should avoid this serious constitutional question by interpreting the public trust doctrine not to apply to groundwater extraction.