A Regional-Scale Index for Assessing the Exposure of Drinking-Water Sources to Wildfires

Abstract

Recent human-interface wildfires around the world have raised concerns regarding the reliability of freshwater supply flowing from severely burned watersheds. Degraded source water quality can often be expected after severe wildfire and can pose challenges to drinking water facilities by straining treatment response capacities, increasing operating costs, and jeopardizing their ability to supply consumers. Identifying source watersheds that are dangerously exposed to post-wildfire hydrologic changes is important for protecting community drinking-water supplies from contamination risks that may lead to service disruptions. This study presents a spatial index of watershed exposure to wildfires in the province of Alberta, Canada, where growing water demands coupled with increasing fire activity threaten municipal drinking-water supplies. Using a multi-criteria analysis design, we integrated information regarding provincial forest cover, fire danger, source water volume, source-water origin (i.e., forested/un-forested), and population served. We found that (1) >2/3 of the population of the province relies on drinking-water supplies originating in forested watersheds, (2) forest cover is the most important variable controlling final exposure scores, and (3) watersheds supplying small drinking water treatment plants are particularly exposed, especially in central Alberta. The index can help regional authorities prioritize the allocation of risk management resources to mitigate adverse impacts from wildfire. The flexible design of this tool readily allows its deployment at larger national and continental scales to inform broader water security frameworks.

Streamflow permanence in headwater streams across four geomorphic provinces in Northern California

“…In addition, forested headwater streams provide key habitat for fish and other aquatic organisms (Montgomery, 1999; Richardson & Danehy, 2007; Welsh & Hodgson, 2008; Wipfli, Richardson, & Naiman, 2007). Headwater streams also provide the primary source of water supply for domestic, agricultural, and industrial needs in many parts of the world (Brown, Hobbins, & Ramirez, 2008; Furniss et al, 2010; Robinne et al, 2019). Moreover, downstream water quantity, water quality, and aquatic habitat largely reflect the condition of upstream contributing headwaters (Alexander, Boyer, Smith, Schwarz, & Moore, 2007; Dodds & Oakes, 2008; Meyer et al, 2007).…”

Anthropogenic and Climate-Exacerbated Landscape Disturbances Converge to Alter Phosphorus Bioavailability in an Oligotrophic River

“…Gravel-bed rivers such as those found in glaciated forested regions of the Rocky Mountains, are disproportionately important to regional biodiversity and to landscapescale ecological integrity because they concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions [32]. Gravel-bed rivers draining the eastern slopes of the Rocky Mountains are critical source water regions for the province of Alberta [33,34]. However, natural and anthropogenic exacerbated landscape disturbance has degraded water quality in these river systems [6,35] and challenged water treatability [7].…”

A Multivariate Geomorphometric Approach to Prioritize Erosion-Prone Watersheds

“…Integrated watershed management is an alternative for soil management [6][7][8]. Watersheds are one of the spatial units that are used for the planning and management of soil resources [9].…”