Lookout Creek). But because there is not a large percentage of the watershed that is burned above 

 this reach, the increased potential is not great. The lower Big Creek stream channel (below Lookout 

 Creek) is much more stable; therefore, even with a higher percentage of the watershed above that 

 reach being burned the overall risk to streambank erosion is not very great. 



The BAER emergency treatments addressed increasing water flow capacity of any culverts that were 

 deemed undersized for the expected post-fire storm flows. This was done in areas that had moderate 

 or high burn severity only. Many of these undersized culverts were not up-sized; rather several 

 armored overflow-dips were installed in the roads. 



Flood Disturbances 



Flood events are one of the primary natural disturbance processes for a stream channel. A review was 

 done of the U.S. Geological Survey's water flow records for the North Fork of the Flathead River, near 

 Columbia Falls. There are two notable flood events for the flow record of 191 1 to 1997. The June 9, 

 1964 flood was the highest recorded flow record with a flow of 69,100 cubic feet per second. This is an 

 increase of 628% above the base flow of 1 1 ,000 cubic feet per second. This flow is greater than a 

 2000-year return interval flood event (Personal communication Charles Parret, U.S.G.S.). A base flow 

 was not established for the U.S.G.S. gage station at Big Creek; however the recorded peak flow for the 

 1964 flood event was 2130 cubic feet per second. The 1964 flood had a major impact upon the Big 

 Creek stream channel in some areas according to anecdotal information. 



The second highest flood event recorded was on June 7, 1995, with a flow recorded of 59,200 cubic 

 feet per second. This is a increase of 538% above the base flow of 1 1 ,000 cubic feet per second. 

 This flow is approximately a 500-year return interval flood event (Personal communication Charles 

 Parret, U.S.G.S.). The majority of rainfall during this event occurred in British Columbia and stream 

 effects were seen primarily in the northern portion of the North Fork. 



B2.2 Land Use Activities 



The Big Creek watershed has been managed since the 1950s. The major activities have been timber 

 harvest, road building, skid trail construction, and construction of ski runs. There have also been 

 watershed restoration activities that have occurred in the watershed. See Table - 4 for a condensed 

 timeline of management activities within Big Creek. 



The constructed road system within Big Creek is approximately 190 miles of roads. There are 

 numerous road crossings of the stream network, but very little of the road systems is located parallel to 

 a stream in a riparian zone infringing upon the stream floodplain. 



Vegetation management in one form or another, either timber harvest or thinning has occurred on 23 to 

 31 percent of the lands in the three 6 code HUCs of Big Creek. The high intensity harvest (e.g. 

 clearcuts, seed tree cuts) older than 20 years has occurred on 8,307 acres, and on 2,489 acres in the 

 last 20 years. Low intensity harvest (e.g. shelterwood cuts, salvage, commercial and non-commercial 

 thinning) older than 20 years has occurred on 3,878 acres, and on 2,020 acres in the last 20 years. 



Between the January 1985 and August 1997 there was 1768.66 acres of land that were transferred 

 from private to Forest Service ownership. This land was located in the headwaters of Big Creek, in 

 portions of sections 19, 20, 23, and 24. This area was extensively logged during the 1960's and is 

 included in the harvest area discussed in the previous paragraph. The entire Big Creek basin is now 

 currently owned and managed by the U.S. Forest Service. Figure - 7 displays the existing road 

 system and all past forest management activities within the Big Creek basin. 



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