The Three Gorges Reservoir can handle big floods up to a 100-year return period discharge. For rarer floods like a 1,000-year event, the Jingjiang flood diversion area is needed to protect downstream areas. But for extremely large floods with a return frequency of 0.01% or more, even the Jingjiang area isn't enough. To handle these, a network of upstream reservoirs should be used together for flood control.