About the Subdivision Review

Background

In November 2002, Larimer County's Wildfire Safety Program received a $10,000 grant from the Colorado State Forest Service to assist in the development of a County Fire Plan. The Wildfire safety Program is using the grant money to compile a county-wide subdivision wildfire hazard assessment.

This subdivision assessment will be incorporated into the County Fire Plan as serve as a planning tool for future projects and targeted education and awareness programs. Informing citizens, working with fire departments and assisting homeowners and landowners with implementation of wildfire mitigation techniques are intended to improve pre suppression effort throughout Larimer County.

In 1994 the Colorado State Forest Service conducted assessments for some subdivisions but a complete comprehensive list was never created. Since 1994, Larimer County has experience a substantial development in the wildland urban interface and currently there are over 220 subdivisions and 35 acre developments located within the Wildfire Hazard Area.

Subdivision Review Process

sample aerial subdivision photo

Larimer County Wildfire Safety staff conducted assessments on a number of subdivisions and development areas. Assessments were conducted by either an on site inspections or utilizing an aerial photo. The assessments evaluated the subdivision as a whole or on a landscape scale and did not assess individual lots or structures.

The assessment form created in 1994 by the Colorado State Forest was utilized during the process. This form identifies critical items that may contribute to wildfire hazard and assigns them a numerical value; these values are added together to determine a Hazard Rating (low, moderate, high, severe, and extreme). Items evaluated included:

  • Subdivision Design - Ingress/egress, road widths, road grade, average lot size, and street signs
  • Vegetation - Fuel type, defensible spaces present
  • Topography - Slope
  • Fire Protection - Response time, water source/proximity
  • Structure Hazard - Construction materials
  • Utilities - Placement

The assessments are subjective, and site specific but were based on firefighter knowledge, anticipated fire behavior and emergency response. A copy of the assessment form used is attached as an appendix.

Assessments - Questions and Assumptions

Listed below are comments and assumptions that the staff conducting the assessments utilized.

Subdivision Design

  1. Ingress/Egress- How many ways 'in' or 'out' of the subdivision?
  2. Primary Road Width- Are the main roads wide enough for two vehicles to pass each other, or does one need to pull over and yield the right of way?
  3. Accessibility- Is the road steep, have many tight switch-backs, could a large fire engine make it up or down the road?
  4. Secondary Road Terminus- Are there 'loop' roads, could an engine turn around, or would the vehicle need to back out?
  5. Average Lot Size- Are the lots large enough to allow home owners adequate room to construct a proper defensible space? If not, what steps have the owners done to mitigate the problem?
  6. Street Signs- Are the streets, and houses legibly marked in order for fire personnel to find their way?

Vegetation

  1. Fuel Type- primary carrier of fire is- What fuels surround the structure? Is the house in the middle of a meadow? Is the house carved out of a Lodge Pole Pine stand? Does the house have continuous trees or shrubs leading up to it?
  2. Defensible Spaces Completed- How many homes in the subdivision have constructed defensible spaces, how many have not?

Slope

  1. Does the majority of the subdivision site in a flat meadow, or is it carved out of a steep hillside?

Fire Protection

  1. Response Time- How long before personnel are on scene? In districts that have full-time firefighters the response time is less, areas where volunteer firefighters are utilized, response times may be longer.
  2. Water Source Availability (within subdivision) - Is there any water within the subdivision? Ponds, streams, lakes, hydrants, rivers, etc.
  3. Water Source Availability (off-site) - If no water is available within subdivision, where is it? Five minutes down the road, or does it need to be trucked in by water tender?

Structure Hazard

  1. Materials- Does the house have a shake shingle roof or a metal roof? Is the house sided with vinyl siding, or log?

Utilities

  1. Placement- Are the gas and electric lines run under ground or above? Does it even have utilities?

Again, this process is based off firefighter knowledge and decisions are made by looking at subdivisions as a whole, not by concentrating on individual structures.

Conclusion

The Subdivision Assessment process compared all subdivisions and 35 acre developments to one another using the same categories or factors. This process identified the most critical developments in Larimer County and will assist in planning for future projects. Education and awareness programs will target these developments and it is anticipated that citizen interest will increase and provide opportunities for further fire planning and possible fuel reduction projects.