A study by Arizona State University has revealed that most of last winter's snowpack in the White Mountains in eastern Arizona had already melted by mid-March, leading to the first aerial mapping of an entire watershed in Arizona. The study used laser technology to measure the topography of the snow-covered terrain in the Upper Black River watershed. The results hold implications for water management of the Salt River system, which supplies 2.5 million people in the Phoenix metropolitan area. Researchers attributed the shrinking snowpacks to a warming climate, which is predicted to reduce stream flows. Researchers hope to develop hydrological models for predicting snowmelt-driven stream flows, which will guide downstream decisions on storage or release water from reservoirs.