On January 31, 2017, the First Appellate District Court in the case Santa Barbara Channelkeeper v. City of San Buenaventura found that an allegation of excessive water diversion to protect endangered fish species under the rule of reasonableness and the public trust doctrine, could not be resolved without consideration of all competing water users in the system.  

The City of San Buenaventura (City) diverts water from the Ventura River watershed, which is home to Southern California steelhead trout, a species listed as endangered under the federal Endangered Species Act. Santa Barbara Channelkeeper (Channelkeeper) sued the City seeking declaratory relief, alleging that the City’s current diversions are “unreasonable” and a violation of the public trust doctrine because of the effect they have on the fish during the summer months, when water levels are low.[1] 

The City denied that its use of water is unreasonable, and cross complained against other entities who also draw water from the Ventura River watershed, alleging that their water use is unreasonable. Under the Code of Civil Procedure, section 428.10(b) a defendant “may file a cross-complaint setting forth” any cause of action that “arises out of the same transaction." The lower court granted a motion to strike the City's cross-complaint, finding that “the reasonable use and public trust doctrines do not require the court to examine other specific competing water rights on the river to resolve the actual relief that Plaintiff is requesting.”

The Appellate Court disagreed. The Court determined that both the rule of reasonableness (Cal. Const., Art. X, § 2.), which is a fact specific inquiry, and the public trust doctrine, apply to limit all water rights.[2] The Court found that, in this case it must consider the diversion and pumping activities of competing water users in determining the reasonableness of the City’s water use. In addition the court stated that the allegations in the complaint beg the question of whether other water users are at least partially responsible for “the existing conditions in the Ventura River.”  The only way to know how influential the other water users are - or are not - is to look at their water use, too. Specifically, the Court pointed out that the complaint does not allege that: 1) the City consumes more water than similarly situated cities, 2) City water users engage in inherently wasteful practices, 3) competing water users take only de minimis amounts of water, or 4) the City’s water rights are junior to those of all other entities who pump and divert water, requiring it to forgo its share of water for public trust purposes.

The Court held that because the complaint alleges unreasonableness based solely on the resulting flow in the river channel, it cannot render a declaratory judgment without considering other water users. This holding is consistent with the balancing of competing beneficial uses of water when making reasonable use and public trust determinations.