How Wildfires Are Polluting Rivers and Threatening Water Supplies

Little Bear Fire
Road 532 on the Little Bear Fire in New Mexico, June 13, 2012. Photo by Kari Greer.

A study conducted at the Yale School of Forestry & Environmental Studies looked at the increasing effects that wildfires are having on water supplies. It is titled, How Wildfires Are Polluting Rivers and Threatening Water Supplies. Below is an excerpt.


As hotter and dryer conditions spawn an increasing number of wildfires in North America and around the world, one of the overlooked impacts of these worsening conflagrations is on aquatic environments and drinking water supplies. Just as wildfires can have a regenerative effect on woodlands, so, too, can fires provide some benefits to streams and rivers in burned areas. But scientists are warning that intense and repeated fires can damage the ecology of waterways by exposing them to the sun’s heat, exacerbating flooding and erosion along denuded hillsides, and releasing toxins such as mercury that are often liberated from soil and tree trunks.

The effect of major wildfires on drinking water supplies can also be severe, as evidenced by fires that burned upstream of places such as Fort McMurray in Canada in 2016; Denver and Fort Collins, Colorado in 2002 and 2012; and Canberra, Australia in 2003. Water treatment plants in those places were overwhelmed by sedimentation, dissolved organic carbon, and chemicals that were released by fire.

With fires burning bigger, hotter, and more frequently, the threats to water supplies and aquatic systems are bound to escalate, according to Deborah Martin, a Colorado-based U.S. Geological Survey (USGS) scientist. She points out that an increasing number of regional, national, and global water assessments are now including wildfire in evaluating the risks to drinking water.

Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire. Google+

5 thoughts on “How Wildfires Are Polluting Rivers and Threatening Water Supplies”

  1. Not only is the water being polluted we have fire smoke for 3 seasons now. We have all the “prescribed” air pollution fires that the forest service somehow thinks is OK since they are purposely lighting the air pollution fires. How can this be OK from a public health aspect?

    1. Martha Bibb and Chuck, it’s a balance, isn’t it? There are competing goals or values, public health and forest health/reduction of larger fires. They are both valid concerns. I don’t know if it’s zero-sum, but I think prescribed burns are necessary.

  2. From the above two posts, and more, it is becoming increasingly obvious that the USFS policy [mgmt] is not paying much attention to the adverse effects of the excessive Wildfires; and Prescribed burns that we are now experiencing! Martha is 100 + % correct

  3. Folks, we’re in this conundrum from a hundred years of fire suppression in the first place; what do you think further suppression will achieve?

    It is really, really interesting to listen to the general comments from people living in the fire-prone west who face these challenges. It is almost as if there is a general amnesia regarding the risks of living in such a region, as if fire has never been an omnipresent component of the landscape.

    1. Still waiting for an intelligent discussion about our out-dated log export laws that prohibit the export of logs in their unmilled form from west of the 100th meridian. If something does not make sense, there is usually a reason for it. What is it?

Leave a Reply

Your email address will not be published. Required fields are marked *