New Mexico Geological Society Annual Spring Meeting — Abstracts

Forested headwaters are crucial for surface water supplies in the Southwestern US, and interbasin water transfers – small and large-scale engineering projects that divert water from remote watersheds across drainage divides – move more than 700,000 acre-feet annually to municipalities and irrigators in the Southern and Central Rocky Mountains. Forest fires are well known to impact the quality of water in a watershed from hillside erosion, and post wildfire debris flows threaten to compromise water supply infrastructure entirely. Our project maps the post-wildfire debris flow annual risk probability for Interbasin Water Transfers. We use readily available remote sensing data to estimate the probabilistic contribution of wildfire severity, precipitation intensity, and take advantage of a database of recorded debris flows to estimate the influence of average basin slope on debris flow generation. To properly quantify the risk of post-wildfire debris flows compromising public water supply it is necessary to incorporate the risk of a disruption of water transferred from outside the basin. Our research aims to produce a regional risk map and, in the future, a detailed assessment of the San Juan-Chama Project, providing actionable insights for water resource management, forest management, and infrastructure planning. Preliminary results indicate headwaters in the Southern Rockies and the San Juan Mountains are at higher risk than transfer projects serving the Front Range of Colorado. By filling this research gap on interbasin transfers, this study has the potential to affect public water supply decision-making in New Mexico and the Rocky Mountain Region.

References:

1. Collar, N.M., and Earles, T.A., 2023, Unique challenges posed by fire disturbance to water supply management and transfer agreements in a headwaters region: Journal of Environmental Management, v. 339, p. 117956, doi:10.1016/j.jenvman.2023.117956.
2. Siddik, M.A.B., Dickson, K., Rising, J., Ruddell, B., and Marston, L., 2023, Interbasin water transfers in the United States and Canada: Scientific Data, v. 10, doi:10.1038/s41597-023-01935-4.
3. Staley, D.M., Kean, J.W., and Rengers, F.K., 2020, Data supporting an analysis of the recurrence interval of post-fire debris-flow generating rainfall in the southwestern United States:, doi:10.5066/P9CHY45I.