Powell’s looming power problem

  due to record-breaking snowfall in the Upper Colorado River Basin, Lake Powell rose substantially, catching river managers off-guard. By late June, the reservoir was nearly overflowing, forcing operators, for the first time ever, to rely on the dam’s spillways. Instead of giving relief, that precipitated a new crisis. A phenomenon called cavitation — a process where water and pressure carve huge caverns inside of the dam — sent shock waves through the spillways’ innards, tearing through the concrete and then the sandstone,