Just so we all start on the same page: there are a lot of dams in California. People have been building dams here since the Gold Rush, and though the dam building boom of the first half of the 20th century is long-over, the dams are still here. This animation shows all the dams in California. To see a breakdown of which ones are connected to hydropower projects (and which rivers in California remain undammed), explore the Water and Power map. Graphics produced by Don Clyde. Research by Lisa Pickoff-White. When people began building dams in California, they probably were probably mostly thinking about gold. Later, they had more lofty ideals: controlling floods, supplying water to cities and farms, generating electricity. One thing they probably weren’t thinking much about: pond turtles. Until recently.