Arizona, Mar 28: A new airborne snow survey led by Arizona State University researchers has revealed a dramatic decline in snowpack across northeastern Arizona, raising concerns about water availability for the Phoenix metropolitan region.
The study, conducted over the Upper Black River Basin—an essential source feeding the Salt River system—found that more than 90% of the snow water equivalent measured earlier this winter had melted by mid-March following a warm and dry season.
The surveys, carried out in collaboration with the Salt River Project (SRP), showed that snow water levels dropped from 9.5 thousand acre-feet (TAF) in February to just 0.8 TAF by March 12, offering a rare, real-time view of how quickly seasonal conditions shifted.
“This is the first time we’ve been able to quantify such rapid changes in Arizona’s snow conditions using airborne observations,” said Enrique Vivoni, director of the Center for Hydrologic Innovations at ASU. “By early March, the basin was nearly snow-free.”
Snowmelt from this region plays a critical role in supplying water to more than 2.5 million residents in the Phoenix area. Experts note that not only the volume but also the timing of snowmelt is crucial for reservoir management.
“This kind of data helps us understand when water will arrive, which is key for managing reservoirs through the summer,” said Bo Svoma.
The project uses advanced airborne technology developed by NASA Jet Propulsion Laboratory, including lidar and imaging spectrometers, to map snow depth and water content across entire watersheds. Unlike traditional ground-based monitoring, this method provides a basin-wide, high-resolution snapshot of snow distribution.
Researchers are also integrating the data into AI-powered hydrologic models, improving the ability to forecast snowmelt and water flow. These efforts are part of a broader initiative to create a “digital watershed twin,” enabling more precise, real-time water management decisions.
With ongoing drought conditions and uncertainty surrounding Colorado River supplies, the findings highlight the growing importance of accurate snow forecasting for Arizona’s water security.
As climate pressures intensify, innovations like airborne snow mapping and advanced modeling are expected to play a vital role in helping utilities optimize water storage, plan groundwater use, and ensure long-term sustainability.
