Californians already paying some of the nation’s highest utility bills could soon get slammed with a costly double whammy: paying more for both power and water. As Pacific Gas & Electric customers brace for potential rate hikes of hundreds of dollars a year, a deepening crisis on the Colorado River is threatening the water lifeline millions of Southern Californians depend on. The warning comes as Lake Powell, the massive Colorado River reservoir on the Utah-Arizona border, enters summer at its