System Analysis of Wildfire ‐Water Supply Risk in Colorado, USA with Monte Carlo Wildfire and Rainfall Simulation

AbstractWater supply impairment from increased contaminant mobilization and transport after wildfire is a major concern for communities that rely on surface water from fire-prone watersheds. In this article we present a Monte Carlo simulation method to quantify the likelihood of wildfire impairing water supplies by combining stochastic representations of annual wildfire and rainfall activity. Water quality impairment was evaluated in terms of turbidity limits for treatment by modeling wildfire burn severity, postfire erosion, sediment transport, and suspended sediment dilution in receiving waterbodies. Water supply disruption was analyzed at the system level based on the impairment status of water supply components and their contributions to system performance. We used this approach to assess wildfire-water supply impairment and disruption risks for a system of water supply reservoirs and diversions in the Front Range Mountains of Colorado, USA. Our results indicate that wildfire may impair water quality in a concerning 15.7 –19.4% of years for diversions from large watersheds. Reservoir impairment should be rare for off-network reservoirs—ranging from at most 0.01% of years for large reservoirs to nearly 2% of years for small reservoirs. System redundancy meaningfully reduced disruption risk for alternative conveya nce routes (4.3–25.0% reduction) and almost eliminated disruption risk for a pair of substitutable terminal sources (99.9% reduction). In contrast, dependen...

Source: Risk Analysis - June 8, 2021 Category: International Medicine & Public Health Authors: Benjamin M. Gannon, Yu Wei, Matthew P. Thompson, Joe H. Scott, Karen C. Short Tags: Original Research Article Source Type: research