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<br />Unfortunately, the Buffalo Creek area fits all of those categories. Strategic planning and mitigation <br />can help to reduce the adverse affects caused by the fire. Previous research suggests that the natural <br />break -up of the hydrophobic soils can occur as soon as 1 to 2 years after the fire. The return of <br />certain grasses and forbs should occur fairly rapidly as well. It will take a much longer time for <br />larger trees and shrubs to develop in the burned watershed. It is likely that flash flooding could be a <br />high risk over the next several years, and will then be a moderate risk for many years thereafter. <br />After the Black Tiger Run fire in Boulder County, the Bureau of Reclamation observed that <br />sediment production and runoff were most significant immediately following the fire. By the next <br />summer season, sediment production had decreased significantly. <br /> <br />E. STREAM CHANNEL STABILIZATION MEASURES <br />Stabilization of the stream channels in and downstream of the burned area is vital to the protection <br />of property, infrastructure, buildings, wildlife habitat, and downstream water quality. Two reports <br />entitled "Stream Channel Stabilization Techniques For The Buffalo Creek Reclamation Project" <br />(reference 20) and "Application of Bonded Fiber Matrix at Buffalo Creek, Colorado" (reference 19) <br />were prepared for the U.S. Forest Service by Woodward-Clyde Consultants. The following text <br />was extracted from those reports and edited by the CWCB. <br /> <br />1. Stream Channel Protection (Vegetative Techniques) <br />Vegetation was the key element to reduce the impacts of excessive erosion prior to the <br />catastrophic events of July 1996, and remains the key to the long term success of future <br />streambank protection efforts. There are four ways that vegetation protects streambanks. First, <br />the root systems help hold the soil together and increase the overall bank stability by this binding <br />network structure. Second, the exposed vegetation (stalks, stems, branches, and foliage) can <br />increase the roughness resistance to flow and reduce the local flow velocities. Third, the <br />vegetation acts as a buffer against the abrasive effect of transported materials. Fourth, close- <br />growing vegetation can induce sediment deposition causing zones of low velocity at the bank <br />where shear stresses may become small enough to allow coarse sediment to settle out of the flow. <br />Vegetation also is less expensive than most structural methods, and it improves the conditions for <br />wildlife. <br /> <br />****** <br /> <br />Factors to Consider in Using Planted Vegetation <br />The basic factors affecting streambank erosion control with planted vegetation are stream flow <br />and flow characteristics, bank geometry, site preparation and protection, vegetation types, <br />revegetation techniques, and plant procurement and costs. As discussed previously, the use of <br />best management practices in the upper watershed burn areas will reduce flows and aid in <br />vegetation establishment for target downstream channel protection efforts. <br /> <br />29 <br />