The planning and decision processes in the Glen Canyon Dam Adaptive Management Program (GCDAMP) strive to balance numerous, often competing, objectives, such as, water supply, hydropower generation, low flow maintenance, maximizing the tributary supplied sediment, endangered species recovery, and flood control. In this context, use of monitored and predictive information on the warm season floods (at point-to-regional scales) has been identified as lead-information that can potentially facilitate improved planning and operations. In this work, we focus on a key concern identified by the GCDAMP, related to the timing and volume of sediment input into the Grand Canyon. Episodic and intraseasonal variations in the southwest hydroclimatology are investigated to understand the magnitude, timing and spatial scales of warm season floods. The coupled variations of the flood-driven sediment input (magnitude and timing) from Paria and Little Colorado Rivers into the Colorado River is also investigated. The physical processes, including diagnosis of storms and moisture sources, are mapped alongside the planning and decision processes for the releases from the Glen Canyon Dam which are aimed at achieving restoration and maintenance of sandbars and instream ecology. GCDAMP represents one of the most visible and widely recognized efforts in the world to manage resources under environmental uncertainty.