Introduction 



Lost Creek is a tributary of western Montana's Clark Fork of the Columbia River. 

 Both streams have multiple water quality problems and appear on Montana's list of 

 impaired streams (MDEQ,1998). Hence under the Clean Water Act, the state is to 

 develop restoration plans for these streams that will restore their health and ability to 

 support their beneficial uses. The Clark Fork River is considered impaired by a number 

 of pollutants, including nutrients, a problem recently addressed in a voluntary nutrient 

 reduction plan. Lost Creek is also considered to be impaired by nutrients and other 

 problems. As a result, several restoration and conservation projects are being undertaken 

 on Lost Creek. This paper evaluates the extent to which these actions on Lost Creek are 

 likely to address its problems as well as those of the Clark Fork River. 



The Clark Fork River Voluntary Nutrient Reduction Program (VNRP) was 

 established to substitute for a mandatory Total Maximum Daily Load (TMDL)for 

 nutrients in the mainstem of the Clark Fork River. The VNRP is centered around the 

 voluntary efforts of four major point sources of nutrients: Smurfitt Stone Corporation 

 (manufacturers of paperboard), and the municipal wastewater treatment plants of Butte, 

 Deer Lodge and Missoula. From the results of a three year nutrient study, Ingman 

 (1992a) estimated that these sources contribute 80% of the total nutrient load to the Clark 

 Fork River during the summer low flow months (July-September), a period when algae 

 production is at its peak. However, historic data also indicates that tributaries contribute 

 approximately 50% and 75% of the yearly loads of total nitrogen and phosphorus, 

 respectively (Ingman, 1992b). Tributary loads arise predominantly from non-point 

 sources such as irrigated crop production, cattle grazing, forestry, and unsewered 

 residential development. Therefore, in addition to reductions from major point sources, 

 the 10-year VNRP calls for a 20% reduction from nonpoint sources. Incorporating 

 reductions from point sources and nonpoint sources and a margin of safety, the VNRP 

 hopes to achieve nutrient targets in the Clark Fork mainstem set at 300 ppb total nitrogen 

 (TN), 39 ppb total phosphorus (TP) below Missoula, and 20 ppb TP upstream of 

 Missoula (Watson, 1999). These targets are expected to maintain standing crop of algae 

 below nuisance levels (Dodds, 1997). 



Based on sampling from 1989-1991, Lost Creek represented a major source of 

 nitrogen to the upper Clark Fork River, particularly with respect to total soluble inorganic 

 nitrogen (TSIN) and was identified as a high priority stream for nonpoint source control 

 of soluble nitrogen (Ingman, 1992a,b). From 1989-91, Lost Creek's TSIN load to the 

 upper river averaged 27.4 kg/day which is comparable to Silver Bow Creek, the receiving 

 waterbody for the Butte wastewater treatment plant. However, Lost Creek was not a 

 significant source of phosphorus to the upper river during the years from 1989-1991. 



Lost Creek is listed on the 303d list as moderately impaired over the lower 17 stream 

 miles for the following probable causes: flow alterations, nutrients, habitat alterations, 

 and siltation (MDEQ,1998). The beneficial uses impaired by these probable causes 

 include contact recreation, coldwater trout fishery, and aquatic life support. In addition, 



