You’re not only picking a fight with every single non-environmental user of California water (including yourself), you’re also challenging the very idea of the appropriation to a beneficial use (which pre-dates California’s statehood).
Now, maybe you’re right and environmental flows under the public trust doctrine should be given such high priority as to dramatically reduce water available for M&I and ag. But I think your argument would have a little more weight if you recognized the massive shift in California law, policy and history that you’re advocating for.
I recognize the massive shift in California law, policy and history that I’m advocating for, although given my druthers, I wouldn’t be advocating based on a doctrine like the public trust. Given my druthers, I wouldn’t be working in our current water rights system at all. Appropriative rights are fundamentally stupid (lock in wealth and water use based on arrival times from two centuries ago?). The only advantage they have is that they currently exist and include a prioritization method. If I got to start from a clean slate, I’d do something like give every person a headright of 50gppd and prime soils 3AF/A-yr for farming. If you don’t farm with it on that land, it reverts to a common pool. If there’s leftover after environmental needs are met, the state can auction it for the short to medium term. Given that I don’t have any respect for the current system, I don’t mind that what I argue challenges the very ideas that underpin it.
That said, my complaints about almonds in particular could be kludged into our current system. A Constitutional amendment could declare that growing pleasant snacks that require a constant water supply for the rest of the world is simply not a reasonable use of water when our climate is becoming even more variable and our fish go extinct. An approach from the “reasonable and beneficial” angle would fit the crazy system we have now but still solve this problem.