Stage 1 fire restrictions, enacted for unincorporated areas of western Boulder County.

2020 Cal-Wood and Lefthand Canyon Fires

Cal-Wood & Lefthand Canyon Fires

Cal-Wood Post-Fire Flood Risk Meetings

Boulder County invited all homeowners and residents of the Left Hand Creek West area And South St. Vrain Creek area to attend one of two Cal-Wood post-fire flood risk virtual meetings on April 6 and 8, 2021. The meetings were free and open to the public.

The Cal-Wood Fire not only burned trees, lichen, and soil, but in severely burned areas the potential for hillslope erosion could cause small or large landslides and debris flows in a flash flood scenario. Post-fire flood risks were discussed at the meetings, including how residents and visitors can prepare, stay alert, and be forewarned of potential risks.

Presentations from the National Weather Service, Boulder County Parks & Open Space, Boulder County Office of Disaster Management, local fire departments, and Left Hand Watershed Center explained how residents can sign-up with the Everbridge alert system, be prepared, and stay informed.


Property owners are responsible for the cleanup of their property, and in many cases there may be insurance coverage for this cleanup. Please check with your insurance provider for your policy details about cleanup. Cleanup includes the removal of all hazardous vegetative debris, yard and household debris, and remaining structural elements including foundations that cannot be reused due to damage. A foundation must be evaluated by a Colorado Licensed Structural Engineer if you wish to try and re-use it.

Boulder County has curated a list of possible local contractors (this list is not a complete list of available contractors).

Foundation Evaluation and Removal

Wildfire usually destroys the structural integrity of structure foundations. Evaluation of the foundation should occur concurrently with property clean up so it can be removed with other debris if it is not usable. Foundations should be evaluated by a Colorado state licensed engineer, typically a structural engineer, when determining if they can be reused. If the foundation is not reusable it should be removed as part of the property clean up. If the foundation is determined to be intact and structurally sound it may be integrated into the building permit plan set for the new dwelling.

A deconstruction permit from Community Planning & Permitting is required for the removal of structural elements on your property. At times, clean up may also require the installation of temporary electrical service, a permit is required for the installation of temporary electrical service.

Permit applications for deconstruction and for temporary electrical service will be made through Boulder County’s online portal. You will need to register for an account if you don’t already have one.

Once a permit is issued and the work is completed, an inspection is required to close out the permit. Please schedule an inspection by emailing the building inspectors directly at

Foundations may remain in place for one year after initial deconstruction of the standing walls or until April 17, 2022. If a foundation is left in place, safety fencing must be erected around the perimeter of the foundation and mulch placed in disturbed areas to control erosion.

Health and Safety During Cleanup

The health and safety of people is a significant concern when cleaning up structures destroyed by fire due to the nature of the materials that have burned. The State of Colorado is requiring the submittal of a form related to the property clean up and has published a set of guidelines to be followed when undertaking property cleanup:

Other Considerations

OWTS a.k.a. Septic

If your tank and/or soil treatment area (leach field) was not damaged, it could be reused if the property is redeveloped. Sewer lines should be capped until ready to be reconnected. Consider having the tank pumped as part of your property clean up.

If the property will not be redeveloped, the septic tank should be properly abandoned. Have the tank pumped and then filled with sand or gravel, remove, or crush and leave in place.

When returning to your property, inspect the area where your septic system is located for signs of damage from fire and traffic from fire-fighting operations. If you feel your septic system may have been damaged, discontinue use until a licensed professional has inspected the system. The system may have been impacted if:

  • Plastic piping above ground has melted.
  • Evidence of vehicle traffic in the area of the system.
  • The raised system was in the direct line of fire (i.e. grass on top is scorched).
  • There is damage in the area where the pipes enter the home.

Learn More

Questions? Contact Boulder County Public Health Water Quality at or 303-441-1564.


If you are serviced by a well inspect your wellhead for damage. If there is damage cover the wellhead and contact a well service provider.

If you are serviced by Left Hand Water District they have already removed meters from any properties that were a total loss in these wildfires. You do not need to contact them about disconnecting service.

If you want to restore your service at some point in the future, please contact Left Hand Water directly at 303-530-4200.

If water is supplied by another service provider please contact them directly.

Insurance Coverage

If your property is damaged or destroyed, the guidance provided below will help you get started on the road to recovery, make good decisions, and keep moving forward:

Each insurance provider and policy is different, so be sure to reach out to your specific provider for more information about your coverage options for cleanup and the options for the future of your property.

Natural Disaster Property Valuation Process

Please see this brochure from the State of Colorado.

By the middle of November the Boulder County Assessor’s Office will finish prorating the values for any destroyed homes from Cal-Wood or Lefthand Canyon fires. The value will be prorated using Oct. 17, 2020 as the date the homes were destroyed. The properties will only have taxes calculated on the value remaining on the property. This is for taxes payable in 2021.

On Dec. 15 the Assessor will report the reduction in value to the Boulder County Treasurer where he will verify the property tax that is eligible for reimbursement from the State Treasurer. The State Treasurer will reimburse the county for the remainder of the taxes due for the properties. For properties that are completely destroyed the property owners will not owe taxes next year.

Properties that have been damaged (but not destroyed) do not qualify for proration or tax relief. The Assessor’s Office will review properties in January to make sure they have been described accurately.

As long as the Assessor’s Office finds evidence of the intention to rebuild a home, the land will be taxed at the residential rate for two more years. Intention to build is generally shown in building permits being pulled to rebuild the home. In 2023, if no home is built, the land will be reclassified and taxed as vacant land.

The properties that have Senior or Veterans Exemptions keep the exemption for the 2021 tax bill. If the property owner shows intention to rebuild the exemption will stay on the property and it will stay on the property unless in 2023 we reclassified the property as vacant land. If rather than rebuild, they chose to buy a new home (in any county in Colorado), they can apply for the Senior Exemption for their new home in 2021 using the Long Form. They will not need to meet the required years of ownership criteria on the new home. The Senior Exemption Long Form can be requested from the Assessor’s Office in January.

On February 25, 2021 the Board of County Commissioners approved Docket DC-20-0004: Article 19 Cal-Wood Fire – Land Use Code Text Amendments. This approval creates section 19-400 in the Land Use Code which establishes an interim permitting procedure for rebuilding structures destroyed by the October 2020 Cal-Wood Fire. The purpose for these regulations was to streamline the county review process and focus that review on the relevant issues. These new regulations replace Site Plan Review (SPR) and combine the planning review with the building permit review. This approach shortens the overall process to 6-7 weeks total rather than a 6 week SPR followed by the several week BP review.

For information about approved regulations or to discuss your rebuilding project prior to submitting a building permit, please contact Hannah Hippely,, (Long Range Planning Manager, Boulder County Community Planning & Permitting) or Kim Sanchez,, (Deputy Director, Boulder County Community Planning & Permitting). View Article 19-400.

If you are in the cleanup phase it may be helpful to know the newly adopted element of the Land Use Code expressly permits you to leave the foundation in place for 18 months after the fire. We realized that people may want to have the foundation evaluated for reuse in the new construction. The only requirements in the new provisions for keeping the foundation in place are that the foundation be fenced off for safety reasons and that the areas disturbed by the initial cleanup be mulched to prevent windblown dirt and erosion. Fencing can be simple t-post and plastic construction fencing such as those found at hardware stores. See an example of a simple t-post. See an example of plastic construction fencing. This should be installed around the foundation. Mulch should cover any bare dirt.


BuildSmart logoSince Boulder County BuildSmart, the county’s building code requirements and energy efficiency code, may drive your design, we held a community meeting on Jan. 11 with property owners, architects, and contractors to provide information on this program and answer questions. View a recording of the county’s building code requirements and energy efficiency code meeting.

Please take a look at the regulations in place through the BuildSmart program. All new construction in Boulder County will need to adhere to the regulations within BuildSmart (this may include adding things like indoor sprinkler systems). Don’t hesitate to contact Ron Flax,, Chief Building Official, to ask questions and learn more about BuildSmart and other building code requirements.

Lighting Requirements

View Boulder County’s outdoor lighting requirements.

Revegetation Guidance

View information and resources to guide the revegetation process.

Boulder County received funding through the US National Resource Conservation Service Emergency Watershed Protection (NRCS EWP) Program which will help pay for aerial mulching, tree mastication, and sediment control structures in the burn area. We are hoping to get a helicopter company on board and flying mulch April-June. Work on the Mountain Ridge HOA property will include tree mastication and will occur in the same timeframe.

The bulk of the funding from the NRCS EWP Program will be spent applying wood mulch over about 1,500 acres of the moderate and high severity burn areas on slopes 20-60%. Many studies have shown that mulching, either with wood or straw, is the single best thing you can do to mitigate for soil erosion and debris flows. The money cannot be used on Federal lands, so we are not doing work on USFS lands, only County and larger private parcels. To that end, we have identified the HOA lands above both subdivisions as candidates for treatment. There is no plan to mulch private parcels.

Our Forester and others have said that the slope is accessible enough to allow a machine to masticate the trees. You may or may not be familiar with this practice, but it uses what is essentially a high clearance tracked excavator with a shredding attachment where the bucket would usually be. It takes standing dead trees and shreds them into mulch. This practice has multiple benefits. One, it provides a woody mulch covering on the soil without the need for finding trees off site to grind for that mulch. Two, it removes the dead hazard trees, which can be both a safety and an aesthetic concern. We would not remove every tree, likely leaving pockets around rock outcrops or other areas, aiming for treating approximately 70% of the slope. Of course, we will need permission from the HOAs to do this. We are in communication with the HOA presidents.

A second part of this discussion is the hazard trees that exist along access roads and driveways and on each of the private parcels. Unlike the HOA lands, private land in your subdivisions is not part of the funded EWP work. The County assumes this work may be completed by each landowner and their insurance company, or the larger HOA can coordinate something. If this can be done in a timely fashion, the County would be interested in using the trees as mulch on other areas of the fire. If it can be organized across the subdivision with the logs stockpiled in an accessible place, our contractor could haul the logs, thus helping us and providing some cost savings on your end. The specifications we have are 8-inch diameter minimum, de-limbed logs. This would likely need to be done by mid-April.

Additional Restoration Resources:

Flash floods are a real concern in burn areas. The severely burned landscape is likely to flood all small and large canyons and deposit tons of debris and mud in many areas. It is expected that rain events as small as 0.35 inches in 15 minutes or 0.75 inches in one hour could cause a flash flood. Because of this, Flash Flood Warnings will be issued when rainfall at these levels are detected by radar or reported by spotters. Small Stream Flood Advisories will be issued for lower rainfall amounts, 0.5 inch in one hour. A Flash Flood Warning means immediate action is needed to protect life and property. An Advisory is issued for minor flooding that is not forecast to be a threat to life or property. However, the Advisory may be upgraded to a Flash Flood Warning if additional rain falls (see below for National Weather Service term definitions). Keep in mind that these rainfall thresholds are commonly seen as frequently as 2-3 times per year. It doesn’t take much rain on a burn scar to cause flash flooding and debris flows.

The risk of flash flooding with associated debris flows and mud flows is increased by soils previously saturated by snow or smaller rain events. The combination of conditions that can trigger a debris flow can make them unpredictable. Saturated soils are more common in the spring, and afternoon thunderstorms are common during the monsoon season (approximately June 1 through Sept. 30).

Flash flooding and debris flows may affect:

  • Marietta and Plumley canyons
  • Fire access road north from Main Trailhead parking lot to Plumley canyon
  • Main Trailhead parking lot
  • Geer Canyon and Geer Canyon Road
  • Corral Trailhead parking lot
  • Lefthand Canyon Drive
  • Lefthand Creek between Geer Canyon Drive and US36 and downstream to Longmont

Flooding is likely to be seen in Lefthand Creek all the way to Longmont and beyond. Discolored, muddy, sediment-laden, and/or ashy water is expected and water may have higher levels of certain contaminants than normal runoff.

Emergency Alerts

Sign up to receive reverse 911 emergency messages for potential flooding. Messages are generated by the Office of Emergency Management using Everbridge Alerts.

Staff Contacts

Emotional Well-Being

One of the key lessons learned from previous wildfire and flood disasters is that these events can have a significant impact on an individual’s well-being. And it impacts everyone differently and at different times, sometimes right away and sometimes months later.

Adults and children across the community who were impacted by the fires may experience normal stress response symptoms like mood swings, sleep disruption, and other stress reactions.

The Community Foundation of Boulder County has allocated a portion of the 2020 Fires Relief Fund to support the Wildfire Mental Health Program. WMHP offers up to $500 towards five individual therapy sessions (a maximum of $100 per session), or up to $875 towards five family therapy sessions (a maximum of $175 per session) and provides a pool of licensed providers from which to choose. Here are links to some of the press we’ve done to explain the program:

Michelle Stinnett
Recovery and Resiliency Manager

Hannah Hippely
Long Range Planning Manager
Community Planning & Permitting

Joycelyn Fankhouser
Emergency Management Coordinator
Housing & Human Services

Sharon Bokan
Small Acreage Coordinator
CSU Extension Office, Parks & Open Space

Kim Sanchez
Deputy Director
Community Planning & Permitting

Ron Flax
Chief Building Official
Community Planning & Permitting

Therese Glowacki
Resource Management Manager
Parks & Open Space