Dr. Jack Schmidt speaks about the fate of the Colorado River ecosystem in Grand Canyon, primarily determined by large-scale, basin-wide decisions about how to allocate increasingly scarce water supplies. Decisions about how to distribute long-term water storage in Lakes Mead and Powell and how much water to deliver from the Upper Basin to the Lower Basin each year are the primary drivers of ecosystem conditions in Grand Canyon. The existence of Lake Powell and the existence of its present array of water release structures perpetuates the continuing fine sediment deficit in Grand Canyon and continues to create a highly perturbed temperature regime. Reoperation of Glen Canyon Dam to moderate the range of load-following, modified hydropeaking releases can only accomplish a small degree of ecosystem improvement in Grand Canyon. New negotiations among the federal government, state governments, and Mexico about how to respond to impending decreases in watershed runoff provide an opportunity to reconsider the fundamental agreements and infrastructure that now control the Colorado River.