Arizona public power utility Salt River Project and Arizona State University have developed a new approach for estimating the water benefits of forest thinning treatments by creating a model that is being recognized as a leading-edge method for analyzing forest thinning’s impacts on water, SRP said on May 21.
After a wildfire, rainfall washes ash and debris into rivers and reservoirs. The large amount of material that washes into SRP’s reservoirs reduces the system’s water storage capacity and can damage water infrastructure downstream such as dams and water treatment plants.
SRP and ASU piloted an effort in Arizona’s Kaibab National Forest that determined forest thinning on about 3,400 acres would generate a benefit of approximately 230 acre-feet, or nearly 75 million gallons, of water during the first year.
Also, SRP and ASU are modeling projects in the East Verde River and East Clear Creek watersheds, which provide water to the Town of Payson and are areas at high risk for catastrophic wildfire. Results from that investigation in the Coconino National Forest are expected later this year.
The researchers created a high-resolution map of the watershed -- one that accounts for trees along with their height, size, and species using light detection and ranging (LiDAR) survey and high-resolution photography of the land. The LiDAR, combined with other image data, generated a precise, three-dimensional surface of the watershed.
SRP worked with Professor Enrique Vivoni, Director of the Center for Hydrologic Innovations at ASU, and graduate students and postdoctoral scholars from the center to combine the LiDAR results with other publicly available datasets to create a model of a thinning project area.
SRP chooses forest thinning projects to fund based on several factors, including potential water benefits, reducing wildfire risk and protecting vital infrastructure and communities.
The utility works with the U.S. Forest Service and the Arizona Department of Forestry and Fire Management to collaboratively choose which forest thinning projects to focus on.
This research, conducted by the ASU Center for Hydrologic Innovation, is part of the Arizona Water Innovation Initiative.
The Arizona Water Innovation Initiative is a statewide project led by the Julie Ann Wrigley Global Futures Laboratory in collaboration with Ira A. Fulton Schools of Engineering.
Through this initiative, ASU works with industrial, municipal, agricultural, tribal and international partners to rapidly accelerate and deploy new approaches and technology for water conservation, augmentation, desalination, efficiency, infrastructure and reuse.
