The Grand Canyon will be experiencing a spring of yesteryear, as water flow rates from the Glen Canyon Dam will be significantly increased, then throttled back in a high-flow experiment that runs March 4 through 9. The result will be a controlled swelling of downstream canyon waters. The goal of the high-flow experiment, the third since 1996, is to see if such high flows can help reconstruct some of the canyon’s beaches and sand bars that are instrumental to ecological systems and native fishes that have suffered since the building of the Glen Canyon Dam in 1963.