“Much of the new plan focuses on habitat preservation for a small species of fish known as the Delta smelt. Water allotments from the Bay Delta have been shrinking for years because the dwindling numbers of Delta smelt have triggered provisions in the Endangered Species Act. Numbers for the Delta smelt, which is at the base of a food chain that goes up to much larger fish, such as Chinook salmon, began dwindling in 2001 and reached a nadir in 2009, before making a slight resurgence in 2011.”