… The story of how the Aurora wound up here, decayed and posing a threat to Stockton’s drinking water supply, is a tale emblematic of California’s Delta. The estuary at the head of San Francisco Bay provides fresh water to two-thirds of the state. But it is also a world unto itself, its winding channels home to fifth-generation farm families, solitary fishermen, houseboaters and artists living off the grid — and its delicate ecosystem under constant threat from a variety of assaults, not the least of which are abandoned boats and their toxic spew. The Aurora’s demise is the saga, too, of the broken dreams of a long line of men who have been bewitched by this ship. They include Chris Willson, the most recent owner willing to be publicly identified. Willson says he sold the boat last fall to a buyer who doesn’t want his name disclosed, after finally accepting, with a crushing thud, that his vision for a resurrected Aurora would never come to fruition.