By — Martha Bellisle, Associated Press Martha Bellisle, Associated Press Leave your feedback Share Copy URL https://www.pbs.org/newshour/nation/bigger-and-more-frequent-wildfires-threaten-water-supplies-across-the-u-s Email Facebook Twitter LinkedIn Pinterest Tumblr Share on Facebook Share on Twitter Bigger and more-frequent wildfires threaten water supplies across the U.S. Nation Nov 13, 2026 12:21 PM EST Wildfires leave behind charred trees and scorched vegetation that impact the streams and rivers providing drinking water to much of the country, and new studies show that contamination could remain for more than a decade. These findings about the longevity of contamination in the nation's drinking water supplies are especially concerning as climate change and increasingly strong El Niño weather events, which intensify drought conditions, have led to bigger and more frequent wildfires in the U.S. So far in 2026, there have been 68,179 blazes burning more than 14,062 square miles (36,420 square kilometers). Grow your mind Subscribe to our Science Newsletter to explore the wide worlds of science, health and technology. Enter your email address Subscribe Form error message goes here. Thank you. Please check your inbox to confirm. After a wildfire sweeps…
Bigger and more-frequent wildfires threaten water supplies across the U.S.
In short
Forested watersheds provide drinking water to nearly two-thirds of U.S. municipalities, but burning hillsides strip them of their natural ability to filter runoff. When subsequent rains flush sediments into rivers and reservoirs, treatment plants frequently shut off intakes to avoid processing toxic materials, while nutrient-dense runoff promotes potentially harmful algal blooms. In Las Vegas, New Mexico, disruptions following the 2022 Hermit's Peak/Calf Canyon fire forced residents to depend on bottled water for months, with issues persisting four years later.
Key points
- Severe burns overwhelm natural water filtration systems, causing treatment facilities to…: Severe burns overwhelm natural water filtration systems, causing treatment facilities to temporarily shut off their intakes.
- Runoff containing nutrient-dense sediment settles into reservoirs and raises the risk of…: Runoff containing nutrient-dense sediment settles into reservoirs and raises the risk of dangerous algal blooms.
- Affected towns may endure clean water shortages and prolonged reliance on bottled water w…: Affected towns may endure clean water shortages and prolonged reliance on bottled water while funding costly new treatment facilities.