Elevations in the Meadow Creek watershed range from 3 160 feet at the confluence with the 

 Thompson River to 5760 feet at the watershed divide. Precipitation varies less than 20 inches 

 per year at the lowest point, to 30 inches at the higher elevations. 



The Meadow Creek watershed is a 9,504-acre tributary to the Thompson River. Management of 

 the drainage is mixed between Plum Creek Timber Company (6,170 acres), U.S. Forest Service 

 (987 acres), State of Montana (1,172 acres) and the remaining acreage owned by other private 

 industrial entities. 



1. Instream Sources of Sediment 



Meadow Creek at the confluence with the Thompson River generally flows less than two 

 months each year. Duration of flows is closely related to snowmelt. This area was 

 inventoried during 2000 for sediment sources, channel stability and morphologic 

 characteristics of the stream channel. The portion of Meadow Creek in Section 4, 

 adjacent to the State managed parcel is considered to be a Rosgen type C4 channel. 

 Sediment supply is moderate to high in this type of channel as evident by the well formed 

 point bars. In-channel sediment sources are limited to outcurves and constrictions. The 

 current condition of this channel is relatively stable. 



The tributary to Meadow Creek that drains the majority of Section 16 is a class I stream 

 due to the perennial nature of the channel. During the 2000 inventory, no fish species 

 were noted. Stability of the lower portion of the channel is considered to be 'fair' given 

 that the Rosgen channel type is a B4a. A 'B' type channel is relatively stable that is not 

 associated with a high sediment supply (Rosgen, 1996). This is supported by channel 

 inventory data, which concluded that sediment sources from within the channel are 

 limited in size and number (Butts, 2000). Upstream of the confluence of the two first- 

 order channels in the northwest comer of Section 16, stability is considered to be good 

 due to a combination of the channel morphology and the vegetation present in the 

 riparian area. All of these streams are class I or II streams as described in the SMZ law 

 (ARM 36.1 1.312). 



2. Upland Sources of Sediment 



During the sediment source inventory, no sediment sources to streams were identified on 

 the proposed haul road within State ownership. The road on other ownerships has been 

 upgraded with surface drainage to meet BMP's. 



3. Cumulative Effects 



Water yield in Meadow Creek was estimated using the Equivalent Clearcut Acre (ECA) 

 method as described in Haupt et al (1996). Allowable ECA in the watershed is 3564. 

 Harvest levels beyond the allowable ECA represent potential risk beyond those levels 

 identified by DNRC as acceptable. The predicted cumulative ECA is approximately 

 2650 acres for analysis year 2003. This equates to an annual water yield increase of 

 10.2% over pre-disturbance levels. The threshold of concern for this watershed was set at 

 15% after considering the acceptable risk level, channel condition, beneficial uses present 

 and potential for adverse impacts. 



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