S.F. Bay is no longer an environmental disaster. Here's what drove incredible transformation

Full of cold, fresh rainwater and snowmelt from the Sierra, the San Francisco Bay is in a strikingly different place than it was last summer.

Water gushing out of the delta is flushing out pollutants and contaminants and giving endangered baby salmon a helpful push into the ocean. Longfin smelt and yellowfin gobies are spawning in the usually swampy southern end of the bay, and sediment coming in from mountain streams is replenishing the structure of its basin.