4.3.1.3 Sediment Yield 



4.3.1.3.1 Alternative A: No Harvest (No Action) 



Increases in sediment delivery and erosion are expected to be moderate in 

 high severity bum areas. The main dehvery area is expected to be 

 Wallace Creek, where a Class I perennial stream channel is present below 

 the bum area. In Ashby Creek, Dirty Ike Creek and Donovan Creek, 

 erosion is expected to be moderate, but sediment delivery is expected to be 

 low. There are two Class II stream channels in Ashby Creek, but neither 

 has direct continuous delivery to any other body of water. There are 

 approximately 8. 1 miles of rehabilitated dozer line and 16 acres of safety 

 zones and drop points that may result in increased sediment yields until 

 they are vegetated. Water bars, slash placement and seeding on these 

 areas, is expected to help reduce erosion rates. 



There is direct sediment delivery occurring at stream crossings and areas 

 where the road is poorly located adjacent to the stream channel in all four 

 watersheds. 



4.3.1.3.2 Alternative B: Harvest 



Increased sediment yields as a result of the wildfire and wildfire 

 suppression activities are expected to occur. The risk of increased 

 sediment yield resulting from the proposed harvest activities is expected to 

 be low. Harvest operations would consist of ground based and cable 

 systems. Ground based harvest will occur on slopes less than 40% and 

 under snow covered winter conditions. Cable operations would occur 

 during winter and summer conditions. There will be approximately 190 

 acres of cable harvest and 13 acres of ground based harvest. There will be 

 no ground based or cable harvest within the SMZ. 



As a result of the proposed activities, direct, indirect and cumulative 

 impacts of the proposed action are expected to be low. (See additional 

 cumulative impacts of re-entry in above Water Yield section). 



4.3.1.3.3 Cumulative Effects of Alternative B: Harvest 



Risk of direct, indirect and cumulative impacts to water quality are 

 expected to be low, with implementation of recommended mitigation 

 measures. 



4.3.1.4 Geology and Soil Resources 



4.3.1.4.1 Alternative A: No Harvest (No Action) 



Increases in erosion are expected to be moderate in high severity bum 

 areas-In Ashby Creek, Dirty Ike Creek and Donovan Creek, erosion is 

 expected to be moderate There are approximately 8.1 miles of 

 rehabilitated dozer line and 16 acres of safety zones and drop points that 



Dirty Ike Salvage Environmental Assessment 4-4 



