After suing the federal government, in Spring 2020 the State of California sought an emergency injunction in federal district court requiring the U.S. Bureau of Reclamation to curtail water exports to central and southern California to protect steelhead migrating down the San Joaquin River and through the Sacramento-San Joaquin Delta on their way to the Pacific Ocean. The State argued that, if the Bureau failed to impose the San Joaquin River inflow to export ratio (referred to as the I:E ratio) in May 2020, it would undermine the overall prospects for recovery of the steelhead.
In litigation in the same federal court less than a decade ago, the State argued that imposition of precisely the same water curtailment (that is, the I:E ratio) by the Bureau was arbitrary, violated federal law, and should be enjoined. At the time, the State’s expert testified that the best available science demonstrates that the I:E ratio would have “no appreciable benefit” for steelhead and other salmonids. Scientific research published in the intervening decade casts doubt upon the efficacy of the I:E ratio as a means to benefit steelhead.
While the I:E ratio was justified using studies done by releasing and tracking the survival of hatchery-raised Chinook salmon, subsequent research both suggests that (1) it was improper to use Chinook salmon survival data as a surrogate for steelhead survival data (Murphy et al. 2011) and (2) steelhead survival during outmigration is materially higher than Chinook salmon survival (compare Sandstrom et al. 2020 with Michel et al. 2015, and see Salmonid Scoping Team 2017). These research findings are unsurprising because on average steelhead outmigrants are substantially larger than Chinook salmon outmigrants and, therefore, substantially stronger swimmers that are able to complete their journey to the Pacific more quickly.
It is curious that the State of California is willing to invest significant resources in litigation to support the San Joaquin River I:E ratio despite the paucity of evidence that it benefits steelhead, while at the same time the State has turned a blind eye to potentially devastating impacts of its own activities upon the species. The State operates hatcheries on the Feather, Mokelumne, and American rivers that produce artificially propagated and raised steelhead that far outnumber their wild counterparts. These hatchery steelhead pose a significant risk to the genetic integrity of the federally listed wild populations. Yet the State has never sought authorization under the federal Endangered Species Act to operate these hatcheries and has failed to conform to the practices recommended by the best practices outlines by the Congressionally funded California Hatchery Scientific Review Group.
Perhaps if the State were really concerned about conservation of wild steelhead it would take steps to remedy its own non-compliance with the federal Endangered Species Act rather than pursuing litigation as a means to maintain the demonstrably ineffective San Joaquin River I:E ratio.