As prescribed burn season ends at Lake Tahoe, an understanding of what the prescription is
Submitted by paula on Tue, 06/07/2022 - 7:47pm
SOUTH LAKE TAHOE, Calif. - Each prescribed fire in the Lake Tahoe Basin is just that, a fire that satisfies a long list of requirements required in a prescription. Typically the prescribed burning of forests start in the fall when conditions are favorable with moisture on the ground and lower temperatures. As long as the prescription requirements can be met, fire will be added to the forest until spring.
"They don't burn when conditions are dry and hot, they burn when safe to do so," said Lisa Herron who is not only the PIO for the US Forest Service, but also one of the Fire PIT (Public Information team) members, a sub-group of the Tahoe Fire and Fuels Team (TFFT).
TFFT was formed in 2008 to implement the Lake Tahoe Basin Multi-Jurisdictional Fuel Reduction and Wildfire Prevention Strategy. All fire chiefs and agencies around the lake are members and they work in collaboration to protect the forests and other natural resources, the communities and the people around Lake Tahoe.
Through this collaboration that was born out of a need after the Angora Fire, partners intend to continue the collaborations and they will continue moving down that road towards a healthy forest.
What has to be met for that prescription for what used to be called "controlled burns?" Forest fuel managers have moved away from the controlled burn term as operations have to meet criteria to safely burn, including the following:
Correct temperature, fuels, moisture, wind, weather and humidity, and meet the requirements from local Air Quality boards and districts.
There are a lot of conditions that need to be met before a permit is issued to USFS, and state and federal agencies around the basin. All work under the same parameters to put fire on the ground, parameters that are usually only met in fall and winter, and sometimes in spring. There have been times in the past when conditions were favorable in the summer, but that hasn't been the case for a long time with drought conditions and rising temperatures the way they are.
Many ask why prescribed burns happen when there is wind. Burning ahead of storms is actually desirable so wind can pick up the smoke and carry it out of the Basin. If there is no wind, the smoke sits in the Basin and affects communities.
Contingency plans are built into the prescription should the weather or conditions change to something not forecasted. They set a test pile on fire in the morning of a scheduled date, and if it isn't igniting the way the fire team wants, they'll put the fire out and continue at a later date.
The people carrying out these fires are firefighters, and the safety of the firefighters and communities is of the utmost importance, said Herron. They want the operation to be carried out safely.
Sometimes a prescribed fire will get out of hand and not behave as expected, such as the 2019 Caples Lake Fire. Approximately 1,080 acres burned as a prescribed fire from September 30 through October 9. On October 10 the prescribed fire was converted to a wildfire, causing an additional 2,355 acres burned as a wildfire, for a total of 3,435 acres burned. Following fuel treatment work that included strategic understory thinning and pile burning, prescribed burning treatments that included pile and broadcast burning were initiated on September 30, 2019. For over a week burning was within prescription and achieving goals of the project. A red flag
warning for a wind event was forecasted, and fire managers began taking action to secure fire lines. Shifting winds resulted in increased fire activity that took the project out of prescription, the fire became a wildfire, and full suppression efforts began.
Even with the Caples Fire, prescribed fire is still an important tool to remove hazardous fuels. Prescriptions are having to change in Arizona and New Mexico where dangerous drought conditions have caused prescribed fire operations to turn into massive wildfires this spring. Since those fires are still under investigation there is no data on what lead the prescription to not work.
There is now an improved tool in the tool box of forest managers at Tahoe - mechanical thinning on slopes up to a 50 percent grade. Prior to February 2022, the maximum slope allowed was 30 percent. With mechanical forest treatments, all materials are taken out of the Lake Taheo Basin and not saved in piles for burning later.
"This is a step in the right direction," said Herron.
The Lake Tahoe Basin is ahead of the game in thinning forests than other areas because of the way the TFFT works together, using the cutting edge collaboration not seen in other forests, according to Herron.
With major forest thinning projects in the future around Lake Tahoe, extensive planning is underway for the best results.
Herron said she understands the public doesn't like smoke from prescribed burns, but the smoke is less intense and shorter in duration that a wildfire would be (as we know from months of smoke around Lake Tahoe during the past two summers).
In closing she also said we have to look back to the main cause of wildfires - humans. Over 90 percent of fires are caused by humans.
"We need to find a way to get that number down," said Herron. "Smokey Bear is mad!"
For other reading:
https://www.fs.usda.gov/detail/ltbmu/landmanagement/resourcemanagement/?cid=STELPRDB5310205
https://www.tahoelivingwithfire.com/