Golden Gate University Environmental Law Journal


This Article will discuss the Light case from the perspective of my firm’s vineyardist clients—including our understanding of the Reasonable Use Doctrine and its application to the frost protection regulation.

The underlying premise of the frost protection regulation is the theory that reductions in streamflow caused by frost protection diversions cause or contribute to stranding of juvenile salmonids in the exposed gravel banks of the rivers and streams in the Russian River watershed. One of the key issues in Light was whether good science supports this theory. From the perspective of my vineyardist clients, the State Board relied on very weak science in support of this theory. As always, perspective is crucial in determining what level of science is necessary to support a regulation that will impose major costs on vineyardists in Mendocino and Sonoma Counties. From the perspective of my clients, there ought to be sound science underlying the relationship between frost diversions and salmonid strandings before imposing any water use regulation. In contrast, members of the environmental and academic community seem less interested in examining the science and more inclined to accept the State Board’s conclusion tying frost diversions to salmonid strandings—at least in my conversations with these folks.

The Background section presents information on frost protection and the fisheries issues that led to enactment of section 862 of title 23 of the California Code of Regulations (“Section 862”). Part III describes Section 862, and Part IV summarizes the law of reasonable use. Part V describes the arguments asserted by the plaintiffs challenging Section 862 and the rulings by the trial court and court of appeal. Part VI describes Light and discusses the implications of the court’s ruling.