Arizona State University and Salt River Project researchers reported on Mar. 25 that much of the mountain snowpack feeding the Phoenix area’s water supply melted within weeks due to a dry, warm winter. Airborne snow surveys over northeastern Arizona revealed that by mid-March, more than 90% of the Upper Black River Basin’s measured snow water had disappeared since February.
This rapid melt has significant implications for water management in central Arizona, where millions rely on river-fed reservoirs. Accurate measurements help utilities like SRP make informed decisions about storing and using available water during critical spring and summer months.
Enrique Vivoni, director of ASU’s Center for Hydrologic Innovations, said, “For the first time, we were able to quantify the changes in Arizona’s snow conditions using airborne observations.” He added, “Despite near-average conditions early in the season, a snow drought across the western U.S. since late December has limited accumulation. By early March, the Upper Black River Basin was nearly snow-free.”
The three airborne surveys conducted this winter showed little new accumulation between January (9.1 thousand acre-feet) and February (9.5 TAF), followed by a sharp drop to just 0.8 TAF by March 12. Bo Svoma, SRP climate scientist and senior meteorologist said, “This kind of information helps us understand not just how much water we have, but when it’s going to arrive… That timing is critical for how we manage our reservoirs heading into the spring and summer.”
Researchers combined airborne lidar data with satellite imagery and modeling tools to improve forecasts of runoff into SRP reservoirs. According to Vivoni: “These airborne datasets are helping us train artificial intelligence models using satellite imagery… That allows us to turn daily images into estimates of snow cover and water content.”
According to a press release from the City of Phoenix Street Transportation Department the department partners with Arizona State University tech startup Argos Vision, which is developing smart traffic cameras for improved safety as part of a pilot program.
Arizona State University was named number one in innovation for eight consecutive years according to U.S. News & World Report. The university also received high rankings in undergraduate business, nursing, and engineering programs.
As Colorado River supplies remain uncertain amid ongoing droughts and groundwater declines continue statewide, accurate forecasting from projects like this will be increasingly important for long-term planning in Arizona cities reliant on local river systems.
Vivoni concluded: “We’re building toward what we call a ‘digital watershed twin,’ a virtual version of the basin that shows how water is changing over time… By combining airborne data, satellite imagery and models, we can help water managers better track conditions and plan for what’s ahead.”
