The Scott River in Siskiyou County is a navigable waterway used for boating and fishing. In the past two decades, the Scott River experienced decreased flows caused in part by groundwater pumping. Petitioners alleged that groundwater is so hydrologically connected to the Scott River that pumping causes decreased flows in the river, with at times almost every gallon of groundwater pumped decreasing the flow of the Scott River by the same amount. As a result, the Scott River is often "dewatered" in summer and early fall, reduced to a series of pools, which has injured fish populations and impaired navigability. The County of Siskiyou is responsible for issuing permits for wells used to pump groundwater but allegedly does not consider the effect groundwater pumping will have on the Scott River when issuing permits. A 1980 decree by the Siskiyou County Superior Court adjudicated all surface water rights and rights to groundwater interconnected with the Scott River, but the decree does not apply to new wells constructed at least 500 feet from the Scott River. This litigation concerns only permits for new wells outside this "zone of adjudication."
The County of Siskiyou's motion for judgment on the pleadings was denied. Petitioners' cross-motion for judgment on the pleadings was granted. The court ruled that petitioners stated facts sufficient to entitle them to declaratory relief that the public trust doctrine applies to groundwater extraction affecting navigable waters, and to a writ of mandate or injunction compelling the County to consider the public trust when issuing well drilling permits. However, the court noted this ruling does not dispose of the case, as the County denied most factual allegations and petitioners must still prove those allegations to prevail on the merits.
The public trust doctrine protects navigable waters from harm caused by extraction of groundwater where the groundwater is so hydrologically connected to the navigable water that its extraction adversely affects public trust uses. Following National Audubon Society v. Superior Court, if extraction of water (whether from non-navigable tributaries or from groundwater) harms navigable waters and public trust uses, the public trust doctrine applies. Local agencies, as subdivisions of the State, share responsibility for administering the public trust and have an affirmative duty to consider the public trust when issuing permits that may affect navigable waters, and to protect public trust uses whenever feasible. Legislative authorization for local agencies to adopt discretionary groundwater management plans does not preclude or supersede duties under the public trust doctrine.
The court noted that the public trust doctrine does not prohibit the State from permitting actions that harm public trust uses, recognizing that California's population and economy depend on appropriation of vast quantities of water for uses unrelated to in-stream trust values. As a matter of practical necessity, the state may have to approve appropriations despite foreseeable harm to public trust uses, but must bear in mind its duty to consider the effect on the public trust. The court also observed that the specific duties the County may have under the public trust doctrine need not be determined at the pleading stage - only that the County has a duty to consider the public trust when issuing well drilling permits. The court distinguished the holding from the approach taken by the Hawaii Supreme Court in In re Water Use Permit Applications, declining to hold that groundwater itself is a resource protected by the public trust doctrine. The court also addressed but did not rule on the State Water Resources Control Board's authority to regulate groundwater under the public trust doctrine, finding that issue was not properly before the court on these motions for judgment on the pleadings.
This is a case of first impression in California addressing whether the public trust doctrine applies to groundwater hydrologically connected to navigable waterways. The decision extends the reasoning of National Audubon Society v. Superior Court to groundwater extraction, holding that the public trust doctrine protects navigable waters from harm caused by groundwater pumping where there is hydrological connection. The case establishes that local agencies, as subdivisions of the State, share responsibility for administering the public trust and must consider public trust values when issuing well permits that may affect navigable waters. This represents a significant development in California water law at the intersection of groundwater management and the public trust doctrine. While this is a trial court decision from Sacramento Superior Court and not binding precedent beyond this case, it provides important guidance on application of public trust principles to groundwater-surface water interactions.