In the News

Protect your Property from Wildfire While Protecting Lake Tahoe
date posted: December 22 2005

Lake Tahoe Report #80
Aug. 17, 2004
By John Cobourn and Heather Segale

A wildfire in the Tahoe Basin would set back lake restoration efforts a hundred years, according to Charles Goldman, Ph.D., UC Davis Tahoe Research Group. A high intensity wildfire would destroy all vegetation, fill the basin with smoke, and potentially lead to excessive sediment and nutrient loading in the lake.

Many local property owners are already implementing best management practices (BMPs) on their properties to help protect the lake’s water quality. There is also an increased effort to educate property owners about creating defensible space around homes to reduce wildfire risk. What many people may not realize is that they can accomplish these two property improvements at the same time, in an integrated fashion.

Both fire risk and declining water quality are major community issues at Lake Tahoe. This year more than ever, Tahoe agencies are urging homeowners to work on both problems at once. For example, when property owners call one of the conservation districts for a free BMP site evaluation, they are likely to receive not only recommendations for erosion and runoff control, but also recommendations for reducing fuel buildup in the “lean, clean and green” space, 30 feet around all structures. In addition to learning how to infiltrate roof runoff, they might be advised to replace their wood shingle roof with a fire-resistant roofing material.

Some people may have the false impression that defensible space requires bare soil, while BMPs require dense vegetation around structures. Fire districts and conservation districts agree that while property owners need cover soil to prevent erosion, they can do this in ways that do not substantially increase wildfire risk. For example, all agree that a dense stand of highly flammable native shrubs is not a good idea close to structures. Some shrubs can be pruned of dead wood and reduced in height, while others can be cut off at ground level, but the roots should be left in place to hold the soil and allow new shoots to sprout. A year or two later, the older shrubs can be lopped at ground level, and the younger shrubs can be pruned to be attractive, leaving horizontal spaces between them about twice as wide as the shrubs are high.

Another way to cover bare soil and to prevent soil erosion is to cover the ground with mulch. This can be wood chips, bark chips, or leaf and pine needle litter. For bare ground within 5 feet of structures, use inorganic, nonflammable mulch, such as gravel or river rock.

Some people have asked whether pine needles are too flammable to use as mulch. Remove pine needles from grass, walkways, decks, roofs and roof gutters. However, if needles cover bare soil, leave the bottom layer of old, decomposing needles in place to enrich the soil and to prevent soil erosion. This dark layer is called “duff.” Every year or two, when a 2-inch thick layer of newly fallen needles accumulates over the duff layer, carefully remove them with a leaf rake, if within 30 feet of the house. Newly fallen needles are not a major risk if they are no more than 1 inch to 2 inches thick. After pine and fir needles have been compressed under the snow for a winter or two, they tend to knit together, providing good protection from erosion, even during summer thunderstorms.

Whether you are planning to renovate your landscape, landscape a new property, or just install BMPs and defensible space, you might want to incorporate the principles of an “integrated landscape.” The University of Nevada Cooperative Extension publication, the “Home Landscaping Guide for Lake Tahoe,” illustrates the guiding principles for such a design. When using the principles of an integrated landscape, property owners make simultaneous decisions about appropriate use of turf, installation of an automatic irrigation system, defensible space, best management practices, and plant selection for areas needing new ground cover. For example, using turf within 30 feet of a structure provides a ground cover that resists both fire spread and soil erosion. However, placing turf near a water body or the lakeshore will create water quality problems if lawn fertilizer ever escapes to the water.

For more information about integrating BMPs and defensible space and to get a free copy of the “Home Landscaping Guide,” call the Nevada Tahoe Conservation District, (775) 586-7223, ext. 1. In California, call the Tahoe Resource Conservation District, (530) 543-1501, ext. 6. If you live in a multi-family residential complex or own commercial property, call TRPA’s Erosion Control Team, (775) 588-4547, ext. 202.