This past February 180,000 people in and around Oroville were evacuated when the emergency spillway of the Oroville Dam looked like it might fail catastrophically. What went wrong? Did officials react appropriately? More importantly, should they have anticipated and addressed the underlying problems years ago? The situation at Oroville is the latest manifestation of a broad reassessment of dams and their consequences here and elsewhere in the world. Various aspects, from how they are designed, financed and built to how they are maintained and managed, has fallen under scrutiny, and many of the assumptions of the last century have turned out to be wrong or at least somewhat flawed. We will examine these issues and their implications for the future of our vast dam-based water delivery system in California.