The DHES recently reclassified Silver Bow Creek to a 

 Class I stream (DHES 1988a) . The goal of the state of 

 Montana is to have these waters fully support the following 

 uses: drinking, culinary, and food processing purposes after 

 conventional treatment; bathing, swimming, and recreation; 

 growth and propagation of fishes and associated aquatic life, 

 waterfowl, and furbearers; and agricultural and industrial 

 water supply. Although Silver Bow Creek cannot currently 

 support most of these uses, the goal is to gradually improve 

 water quality. An analysis will be performed during each 

 triennial standards review period to determine the factors 

 preventing or limiting attainment of these uses. Permittees 

 who discharge to Class I waters cannot degrade water quality 

 below existing conditions. 



The Clark Fork's surface water quality classification 

 varies within the upper river segment. From Warm Springs 

 Creek to Cottonwood Creek (near Deer Lodge) the river is 

 classified C-2, which means water "suitable for bathing, 

 swimming and recreation; growth and marginal propagation of 

 salmonid fishes and associated aquatic life, waterfowl and 

 furbearers; and agricultural and industrial water supply" 

 (DHES 1988a) . From Cottonwood Creek to the Little Blackfoot 

 River, the water is classified C-1, which is similar to C-2 

 with the word "marginal" removed. From the Little Blackfoot 

 River to the Milltown Dam, its classification improves to B- 

 1, which is water suitable for C-1 uses plus drinking, 

 culinary, and food processing purposes after conventional 

 treatment. 



Heavy metals from waste sites associated with former 

 mining and smelting operations in the headwaters are the 

 major water quality problem in the upper river. Although 

 water quality has improved greatly in the past 3 years due 

 to installation of settling ponds and treatment systems, 

 water quality criteria for protection of aquatic life are 

 still exceeded fairly frequently. 



The middle portion of the Clark Fork extends about 115 

 river miles from below Milltown Dam to the confluence with 

 the Flathead River (Figure 1-4). Major tributaries in this 

 section include the Bitterroot, St. Regis, and Flathead 

 rivers. Just below the confluence of the Flathead River, the 

 Clark Fork becomes a very large river with an average annual 

 discharge of about 20,000 cfs. Like the upper river, 

 streamflow in the middle river is determined by weather, 

 geology, and irrigation. 



The entire mainstem middle river has a water use 

 classification of B-1. The major water quality issue in 

 this segment is the addition of excessive nutrients from 

 various sources. 



1-2 



