{"id":3857,"date":"2021-08-30T20:59:21","date_gmt":"2021-08-31T03:59:21","guid":{"rendered":"https:\/\/calsport.org\/fisheriesblog\/?p=3857"},"modified":"2021-08-30T20:59:21","modified_gmt":"2021-08-31T03:59:21","slug":"a-tale-of-three-critically-dry-years-more-shasta-reservoir-solutions-to-save-salmon","status":"publish","type":"post","link":"https:\/\/calsport.org\/fisheriesblog\/?p=3857","title":{"rendered":"A Tale of Three Critically Dry Years – More Shasta Reservoir Solutions to Save Salmon"},"content":{"rendered":"

Shasta Reservoir is low again at the end of summer in drought year 2021.\u00a0 The pattern is very similar to critically dry years 2014 and 2015 (Figure 1) that resulted in the loss of access to Shasta\u2019s cold water and failure of the winter-run salmon spawn in the summer.\u00a0 Year 2021 is leading to another failure of the winter-run salmon spawn and fry production.\u00a0 Shasta\u2019s cold-water pool supply is depleted, and river releases are too warm (Figure 2).\u00a0 Water temperatures downstream of Shasta held in 2020 (Figure 2) despite high water releases (Figure 3), because 2020 had 1 million acre-feet more storage at the beginning of the year than either 2014 or 2021 (Figure 1).<\/p>\n

The three disaster years could have had different outcomes if as little as 300,000 acre-feet of additional storage had been available in 2013 and spring 2021.\u00a0 If at the end-of-year 2013, storage had been 2 MAF rather than 1.7 MAF, and the additional 300,000 AF been carried into 2014 and 2015 and then used to protect fish<\/em>, the 2014 and 2015 disasters could have been averted. \u00a0If the spring releases in 2021 had been minimized as in other drought years, then the 2021 disaster could have been averted.<\/p>\n

One reasonable strategy for Shasta Reservoir\u2019s storage problems is minimum end-of-year storage prescriptions based on initial storage and water year type, and limiting releases in spring after dry years when storage is at or below 2 MAF.\u00a0 Goals should be set for the next year based on initial conditions end-of-year storage (Figure 1).\u00a0 As stated in a previous post, it is no longer enough to set end-of-September storage targets. \u00a0Climate change means in part that more autumn months are very dry. Exports in the fall (and a transfer season now extended through November) pull down CVP storage or at least slow reservoir refill. \u00a0Storage at the end of November or end of December needs to an explicit part of the carryover calculus. \u00a0Figure 1 shows end-of-November as the requirement.<\/p>\n

Proposed Operating Storage Rules <\/strong><\/p>\n