Long before a fractured spillway plunged Oroville Dam into the gravest crisis in its 48-year history, officials at a handful of downstream government agencies devised a plan they believed would make the dam safer: Store less water there. Sutter County, Yuba City and a regional levee-maintenance agency brought their recommendation to the Federal Energy Regulatory Commission in 2006, when FERC was considering the state’s application to relicense Oroville Dam.