After the 2013-2015 drought, the National Marine Fisheries Service (NMFS) took a deep dive into “lessons learned” to help guide future regulatory permit processes, especially those that address the effects of future Shasta Reservoir operations on endangered winter-run Chinook salmon. The drought proved to be a comprehensive adaptive management experiment on the effects of the US Bureau of Reclamation’s (Reclamation) operation of its Shasta-Trinity Division on Sacramento River and Bay-Delta fish populations. Though the specific lessons learned focused primarily on one listed species, winter-run salmon, the effects manifested in different ways on other listed or special-status native fish species in the Central Valley and Klamath-Trinity rivers, including other runs of salmon, steelhead, sturgeon, and smelt, and even orca in the ocean.
In upcoming posts, I will discuss the ramifications of the “lessons” and their relevance to fish populations and water supply issues. The focus will be on Sacramento Valley salmon and how Reclamation can adjust the operations of the Shasta-Trinity Division to help salmon and other fish populations recover.
March 2021 is a critical stage of decision making in managing resource allocation during what could be another dry year like water year 2020. Reservoir storage levels are low (Figures 1-3), and Shasta’s cold-water supply (Figure 4) is low after a dry year. Water year 2021 is dry so far. The lessons learned need to be applied to avoid the fisheries disasters of the last drought. Will the warnings and lessons be heeded?