A new analysis by engineers at the Contra Costa Water District shows that a decision made a decade ago to protect fish by shifting the timing of water deliveries could be at the root of what is causing populations of Delta smelt and other fish to crash. The engineers found that the shift led to saltier water in the fall, and for some reason, that is leading to fewer fish.The evidence appears to be the strongest explanation yet for an environmental crisis in the Sacramento-San Joaquin Delta that threatens not only the survival of at least one fish species but...