Instead of chasing storms on the ground, Arizona State University researchers and Salt River Project crews are hopping into aircraft this week, flying NASA-style snow sensors over Arizona’s high country to see how much meltwater is headed for Valley taps.
The short series of airborne surveys will use NASA-developed instruments to map mountain snow and estimate, weeks ahead of time, how much of that snowmelt will actually make it into Valley reservoirs. The idea is to give SRP water managers earlier and more precise runoff forecasts so they can better time reservoir releases and protect storage. The first flight is slated for Thursday, with additional sorties over the high-country basins that feed Roosevelt and other Salt River reservoirs.
According to Fox10 Phoenix, the campaign will include three flights that zero in on basin areas upstream of Roosevelt Dam on the Salt River, along with the upper Black River basin near New Mexico. ASU hydrology professor Enrique Vivoni and SRP climate scientist Bo Svoma are teaming up to interpret the aircraft’s snow-mapping data. Officials told the outlet that having that extra lead time could significantly reshape how and when SRP schedules reservoir releases.
How the aircraft measures snow
The flights will carry instruments similar to NASA’s Airborne Snow Observatory, a combination of an imaging spectrometer and scanning LiDAR that measures snow depth, albedo and snow-water equivalent across entire basins. Those measurements let researchers convert surface elevation and reflectance into high-resolution maps of snow-water equivalent, which modelers then use to predict how much runoff will arrive, and when. NASA JPL describes the Airborne Snow Observatory as a proven system for improving basin-scale runoff forecasts.
ASU's role in turning maps into forecasts
Back on the ground, ASU researchers and graduate students will take those snow maps, blend them with high-resolution satellite imagery, and feed the combined dataset into machine-learning models to estimate inflows into SRP reservoirs. "These machine learning and AI techniques allow unprecedented views of the Earth’s land surface," Vivoni told ASU’s Arizona Water Innovation Initiative, which has been building the algorithms and visual tools that local water managers will rely on.
The Arizona Water Innovation Initiative reports that the pilot work has already helped secure follow-on funding to integrate LiDAR measurements with hydrologic modeling for operational forecasting, with the goal of turning these flights into a practical decision-support tool rather than a one-off science project.
Why this matters for the Valley
Even small improvements in forecast accuracy matter when SRP is juggling limited storage across the Salt and Verde river systems. SRP notes that it delivers roughly 244 billion gallons of water a year, about 750,000 acre-feet, to Valley residents, and a significant portion of that supply starts out as high-elevation snowmelt.
A clearer read on how much water is locked up in mountain snowpack, and when it will arrive, can translate into fewer overly cautious releases and more water left in storage for the peak of summer demand. SRP and local reporting stress that the timing of operations, not just total volume, is critical for keeping the regional supply resilient.
What's next for the pilot
For now, this is still a test run. The ASU-SRP team plans to compare the flight data with ground measurements and existing helicopter surveys, then refine their models over the coming months. ASU’s writeup says the early results helped attract follow-on support from the U.S. Bureau of Reclamation to build a snowpack-to-streamflow forecasting system for SRP watersheds, if the method continues to prove reliable.
Students will be hands-on in processing the data and building visualization tools that water managers could eventually use in real time. ASU reported those next steps in February 2025.
For Phoenix-area residents, the project is a quiet but concrete example of how remote-sensing technology can be turned into everyday water security. If these flights give managers even a few extra weeks of accurate notice, utility planners may be able to stretch stored supplies just a bit further when the hottest months roll in.
