a total barrier to upstream movements of WSCT. Wales Creek is one of the few streams 

 in the Blackfoot Watershed where a significant amount of the watershed consists of 

 weathered granite. Streams with this geologic composition are particularly vulnerable to 

 sediment related impacts. In 2003, we began to assess Wales Creek from a restoration 

 perspective. The assessment will carry into 2004 and focus on irrigation and instream 

 flow needs, and determine if sufficient water is available for both. 



Fish Populations 



Wales Creek above the reservoir supports a native fish community of genetically 

 pure WSCT and sculpins. Below the reservoir, Wales Creek supports WSCT. brown 

 trout and very low rainbow trout densities near the mouth, hi 2003, we measured flows 

 and completed fish population surveys above and below the reservoir, as well as in a 

 small spring creek tributary to lower Wales Creek. Our flow measurements recorded 0.9 

 cfs above the reservoir (mile 2.6), no flow immediately below the reservoir (mile 1.9), 1.1 

 cfs at mile 0.3, and 1 .0 cfs (mile 0. 1) below a small spring creek near the mouth. 



Surveys showed higher densities of WSCT upstream of the reservoir (mile 2.6) 

 than below the reservoir (mile 0.1), and the relative abundance of brown trout increased 

 near the mouth (Figure 35). We captured brown trout and low densities of WSCT in the 

 unnamed spring creek, with a combined CPUE of 6.6 fish/100'. 



Catch/1 00" 



Warren Creek 



Restoration Objectives: Restore 

 riparian vegetation and stream habitat 

 for all life stages of trout; improve 

 spawning and rearing conditions; 

 increase recruitment of trout to the 

 middle Blackfoot River; reduce 

 whirling disease infection levels. 



Project Summary 



Warren Creek, a small 

 tributary to the middle Blackfoot 

 River, originates on Ovando 

 Mountain, flows 12 miles southwest 

 through knob-and-kettle topography 

 until its junction with the Blackfoot River at rm 50, with a base flow of -3-4 cfs. Warren 

 Creek water is used for irrigated hay production and livestock watering. Irrigation causes 

 the middle section of Warren Creek to dewater, although the lower section gains inflow 

 from springs and maintains perennial base-flows of 3-5 cfs. Some of the riparian areas in 

 the mid-to-lower portion of the stream were cleared, heavily grazed, dredged and 

 straightened, all contributing to the dedregation of salmonid habitat over most of the 

 length of Warren Creek. Whirling disease had escalated in Warren Creek from mean 

 grade of 0.21 in 1998 to a high of 2.1 in 1999. 2003 monitoring recorded a decline in 

 infection levels (mean grade 0.06). 



G Rainbow trout 

 ^ Brown trout 

 ■ WSCT 



0.1 0.3 1.9 2.6 



Location (stream mile) 



Figure 35. CPUE for salmonids at four sampling locations 

 on Wales Creek, October 2003. 



50 



