Prescribed Burning

Historically fire played a significant role in maintaining the ecological health of our forests and prairies. Low elevation ponderosa pine forests and grasslands burned as frequently as every 5 to 30 years. But with the growing population and urbanization of the West, fire suppression has become the norm. That has allowed forests to become denser and vegetation to grow rampantly, creating larger fire risks for some communities, while also stunting important ecological processes.

Today, scientists have decades of research citing fire as an essential element to maintain forest health and to protect our native species. By introducing prescribed fires, the City of Boulder can restore the natural balance for Colorado’s fire-adapted ecosystems and reduce the amount of fuel in the forest during a wildfire.

In city agricultural operations, fire is an essential tool for maintaining irrigation ditches and ensuring water flows throughout the system. It also can be used to clear fields, control weeds and improve forage for grazing. Low-intensity burns in grasslands and forests remove dead vegetation and needles that can quickly accumulate. A build-up of dead material can inhibit the growth of native plants and decrease the habitat value for wildlife. Burning cycles nutrients back into the soil, and results in more dense and diverse native vegetation.

Regular burning can also remove small trees that create competition for larger, mature trees in a forest. By managing forest density through fire, the remaining trees are healthier and more resistant to high-intensity wildfires and forest insects like Mountain Pine Beetle.

Every prescribed burn goes through an extensive planning process to consider ecological goals, the resources required, potential fire and smoke behavior, crew logistics, and desired weather and fuel moisture conditions. In advance of burns, firefighting staff can use a variety of techniques for controlling the burn. Mowing of fuels, extensive hose lays, wetting down burn boundaries, or burning off small areas of fuel are all tools used to create holding lines around a burn unit. When planning burns, City of Boulder staff take every precaution to ensure that there are either natural or man-made features that serve as “fire breaks,” which help control prescribed burns.

Burn selection is always a balance between risk and benefit. Can we effectively burn an area to meet the ecological goals while minimizing the risk and impacts to surrounding neighbors and resources? The highest priority is public safety. Considerations such as fuel type, topography and the ability to maintain perimeter lines are critical in evaluating potential prescribed burn locations.

It’s also essential to consider the ecological benefits. Every managed area has a list of ecological goals we hope to meet through burning. We also consider the strategic benefit of a prescribed burn on the landscape. With any prescribed fire, one of the end results is a decrease in fuel load, and in certain areas, this can create a fuel break to protect nearby homes and private property.

The city’s Forest Ecosystem Management Plan PDF and Grassland Ecosystem Management Plan PDF – which lay out how OSMP will accomplish its ecological responsibilities mandated by the department’s charter – identify prescribed fire as an important management tool and a high-priority conservation strategy.

The City of Boulder seeks to inform the public about planned burns in advance of any ignitions through social media updates through the city’s Facebook, Twitter and NextDoor accounts and a press release to local media. A banner on top of BoulderColorado.gov will also appear when the city is conducting burns.

If the city is planning burns along the mountain backdrop, the City of Boulder will work with CDOT to include messaging about planned burns on message boards along U.S. Highway 36 and Highway 93. Additional notifications include signs along open space access points and trail junctions, and signs in nearby neighborhoods.

Prescribed burning is only carried out if and when weather and vegetation conditions are acceptable to assure the safety of the public and minimize the potential impacts of smoke. Weather is an important driving factor in prescribed burning and can dramatically influence the success of a burn. In some cases, prep work is completed but the burn may be called off because the proper weather or fuel conditions can’t be met.

Prescribed fire smoke may affect your health. Young children – especially those under 7 years - older residents, those who have pre-existing respiratory or circulatory conditions and pregnant women may be affected by smoke. To avoid smoke, please close windows and stay indoors. For more information, please visit the Colorado Department of Public Health and Environment. Residents will see smoke from small and large burns. Residual smoke may be seen after burns are completed. Firefighters monitor burned areas on an ongoing basis until all heat sources have been determined as completely out.