following the fire was low to moderate on severely burned sites and not 

 extensive over the project fire area. Based on the verified lower 

 hydrophobicity, actual water yields are anticipated to be lower than 

 modeled. 



Each of the streams in watersheds with extensive moderate to high bum 

 severity are anticipated to exhibit in-channel scour as a result of the 

 increases in water yield. The potential increase in water yield could 

 destabilize streambanks in severely burned watersheds and increase the 

 failure of existing debris jams in streams. These anticipated effects of 

 channel scour could result in changes in channel morphology. 



3.2.1.2 Existing Conditions of Geology/ Soil Resources 



The Fish Creek project area is located on moderate to steep slopes with soils 

 weathering from Belt series, Precambrian age sedimentary argillites, 

 quartzites, and limestone bedrock. There are no especially unique or unusual 

 geologic features in the sale area. Landscapes within the Fish Creek Complex 

 area are stable owing to the extensive shallow bedrock and very gravelly soils 

 from belt rocks that are resilient to erosion. There are areas of structural 

 breaklands (unit 64) (see Table 3-3) and localized areas of instability that have 

 considerable soil creep of surface gravels due to the very steep slopes and 

 frost action. Two localized areas of slope instability were identified on steep 

 slopes in the Deer Creek drainage (west Vi of section 16 and south Vi of 

 section 8). 



The dominant landtypes in the Fish Creek project area are steep mountain 

 sideslopes with relatively narrow alluvial valleys. General soil characteristics 

 are listed in Table 3-3. Soil Map units 60QA/B and 60QC are on steep 

 mountain sideslopes of 40-80% slopes with some benches. The 60 A/B soils 

 are on mainly dry south aspects with shallow to moderate depth soils 

 supporting ponderosa pine and Douglas fir. Topsoils are very gravelly silt 

 loams over shallow to moderately deep extremely gravelly sandy loams 

 derived from quartzite and argillite bedrock. Most soils in the area have a 

 volcanic ash surface layer with a silt loam texture that may be mantled by 

 surface gravels. These soils are excessively well drained and droughty which 

 can lead to plant mortality and difficulty to revegetate cutslopes on slopes of 

 southerly aspects. Erosion hazard is moderate due to the high gravel contents. 

 Material is good for road construction and well suited to outslope 

 construction. Cutslopes can be slow to revegetate and susceptible to weed 

 establishment. 



Fish Creek Salvage Environmental Assessment 3-10 



