B - Condition Assessment and Problem Description 



B.I - Water Quality Standards and Concerns 



The DEQ's 1996 and 2000 303(d) Reports - Waterbodies in need of Total Maximum Daily Load (TMDL) 

 Development, describe Big Creek as partially supporting the beneficial uses of aquatic life support and 

 cold water fishery. The probable causes of this impairment on both the 1996 and 2000 303(d) lists can 

 all be linked to sediment, with probable sources being linked primarily to silviculture practices. This 

 watershed restoration plan satisfies TMDL development requirements for sediment and causes relating 

 to sediment (habitat alterations, siltation, bank erosion, and fish habitat alterations). 



The State of Montana has classified the waters in Big Creeks as B-1. Waters classified as B-1 are 

 suitable for drinking, culinary, and food processing purposes after conventional treatment. Water 

 quality must also be suitable for bathing, swimming, and recreation; growth and propagation of 

 salmonid fishes and associated aquatic life, waterfowl, and furbearers; and agricultural and industrial 

 water supply. Additional criteria specific to sediment are found within Section 17.30.623(2)(f) of 

 Montana Water Quality Standards where it is stated that "(N)o increases are allowed above naturally 

 occurring concentrations of sediment, settleable solids, oils, or floating solids, which will or are likely to 

 create a nuisance or render the waters harmful, detrimental, or injurious to public health, recreation, 

 safety, welfare, livestock, wild animals, birds, fish, or other wildlife". 



The logic for the watershed restoration plan is based upon two facts. First, sediments from past 

 upland/stream erosion stored within the stream channel, along with streambank erosion from channel 

 migration and widening, are the primary causes for Big Creek's listing as an impaired water body. The 

 primary existing beneficial use for Big Creek is aquatic habitat for cold water fisheries. Second, the 

 proposed watershed restoration activities would reduce significantly the input of sediments from the 

 upland eroding sites and a large portion of the existing road system. Therefore, we believe that the 

 watershed restoration objectives should be the following: 1) to reduce the sedimentation loading thereby 

 reducing the effect of sedimentation on fishery habitat; and, 2) concurrently with the sedimentation 

 reduction, maintain or reduce the water yield, so that the Big Creek stream channel can achieve dynamic 

 equilibrium. 



The entire Big Creek Basin was included in the area of the watershed restoration plan for two reasons. 

 First, the entire mainstem of Big Creek is identified in the 303(d) report as partially supporting beneficial 

 uses, therefore requiring consideration of all potentially significant sediment sources to Big Creek 

 throughout the watershed. And second, the Hungry Horse - Glacier View Ranger District planning team 

 completed a watershed assessment for Big Creek (November 1999), and is proposing a series of 

 management activities in response to the Moose Fire. These activities include road decommissioning, 

 culvert up-sizing, road BMP work, reforestation, and burned timber salvage. 



B.2.1 - General Watershed Characterization 



General Streamflow Regime Characteristics of Big Creeic 



Big Creek is a 77 mile^ watershed with elevation ranging from 3,300 feet to about 6,817 feet. Big Creek 

 is a fourth order stream about 14 miles long. The average annual precipitation in the Big Creek 

 drainage ranges from approximately 62 inches at the top of Big Mountain to 28 inches along the North 

 Fork Flathead River. Approximately 60% of the precipitation falls as snow, which results in a snowpack 



