transport rates seems to be a function of the duration of bankfull and higher streamflow. Graphs of 

 relationship of total suspended sediment and bedload to stream discharge are displayed in Figures ■ 



10* 



BIG CREEK 1986 TO 1992 



TOTAL SUSP. SEDIMENT <Sc BEDLOAD 



T 

 



R 



D lO"-! 



A 

 Y 



10-' 



^SEDTONS/WY 

 0BEOUM} 



^., 



10' 



—I r 



10^ 10^ 



FLOW CU/FT/SEC 



k-EST. BANKFULL 

 850 CU/FT/SEC 



10* 



Figure - 4 The total suspended sediment and bedload versus stream discharge for Big Creek, for the 

 years 1986 to 1992. 



Suspended sediment/discharge samples were also collected at monitoring site (FL7007) located in the 

 upper reaches of Big Creek, about one-half mile above Nicola Creek. Between 1979 and 1981 a total 

 of 10 samples were gathered. Suspended sediment concentration was not significantly correlated with 

 discharge from these data (Anderson 1988). 



Geology/Landform/Stream Type Characterization of the Big Creek Watershed 



The Big Creek area is underlain by Proterozoic meta-sedimentary rocks that consist mainly of 

 calcareous argillite, dolomite, limestone and siltite. These rocks weather to form silty soils that are 

 neutral to slightly alkaline with about 30 to 70 percent of the soil volume occupied by rocks. There is a 

 volcanic ash surface present on surface of almost all the soils within the Big Creek basin. The ash is 

 very light and porous and is enriched with organic matter, conditions that allow water to move into and 

 through the soil reducing the occurrence of runoff and soil erosion. 



Landform and vegetation are the dominant physical features that affect watershed functions and 

 processes in the Big Creek watershed. Landforms regulate how and where water flows across the 

 landscape. Vegetation influences the erosion processes that occur within the landscape. 



10 



