Can wildfires impact our freshwater resources?
Updated: Aug 20, 2021
Manitoba is experiencing a hot and dry spring resulting in multiple wildfires across the province. The fires have forced some people out of their homes and cottages. To avoid further spread and protect people’s lives, there are limited backcountry activities open in provincial parks. We know that fires threaten communities, our forests, wildlife and other important natural resources.
Can wildfires affect Manitoba’s water supply?
Many Manitobans rely on surface water for their drinking water. And for the majority of Manitobans, this water is part of the Lake Winnipeg watershed. Many communities get their water from the Assiniboine River, Lake Winnipeg, the Whiteshell area or other local surface water sources. Other communities may get their water from underground sources. Fires nearby these water sources can result in less groundwater, more downstream flooding, and the addition of harmful substances into the water.
Does a healthy water system need healthy trees and soil?
Healthy soil can filter out contaminants. The naturally filtered water either seeps into groundwater or flows into nearby streams, rivers and lakes. Forests help stabilize water quantity and are an essential part of flood and drought prevention.
Wildfires impact our forests and the ecosystem services forests provide such as storing carbon, homes for wildlife and filtering water and air. Wildfires burn a lot of the plants in forests, including what’s covering the forest floor. Fires also can burn the topsoil, leaving it hardpacked and unable to absorb much water. If soil and trees can’t soak up or filter rain and snow into the ground, more unfiltered water flows into nearby waterways—sometimes leading to downstream flooding.
Forests near the edge of waterways reduce shoreline erosion. Trees protect the soil from rainfall, and their roots give strength to the ground. Erosion causes the riverbanks to fall apart and adds nutrients, like phosphorus, into the water. Forests help keep runoff from entering our freshwaters.
Are there any potential dangers after fires are extinguished?
Heavy rain or snow after wildfires causes ash and other burned materials to flow off fire-stricken land into nearby water. The water can also receive heavy metals and chemicals from human-made products caught in the fire through runoff.
Why do we need forests for our water supply?
Forests have an incredible effect on the distribution and health of the water in Canada. Two-thirds of people living in Canada get their drinking water from forested areas. The boreal forest cleans most of the water that flows into Lake Winnipeg. We need healthy forests to keep our water reliable and clean. We cannot undervalue our forests. Not enough safe-to-drink water threatens human health.
Could a changing climate lead to more wildfires?
In the past several years, we haven’t faced this much fire danger throughout the province. As our changing climate brings us more severe weather patterns, wildfires are likely going to get worse.
We need to plan and build communities and infrastructure that can support and respond to the shocks and stressors of a changing climate like flooding and droughts. We can protect our forests to protect our water. These kinds of extremes don’t just take an incalculable emotional and social toll on communities, but a huge financial toll as well.
Make sure to follow current fire restrictions, stay safe and stay lake friendly.