Repairs by the Anaconda Company consisted of rebuilding the break in the dam, placement of 

 additional spillway capacity and refacing the dam with new gravel material. The original 24" 

 outlet pipe under the dam was cleared out at both ends and will continue in use. No further 

 repairs were made to the bypass canal since it is intended the canal will not be used in the ftiture 

 due to its poor condition. A new 54" concrete overflow pipe was installed through the dam to 

 replace the bypass canal. Changes were made to the diversion structure at the head of the pond so 

 that runoff water would more readily be transported into the pond instead of entering the old 

 bypass canal. 



During dam repair, four ponds of various sizes were constructed in the Blackfoot River 

 floodplain downstream from the dam. The pond locations were borrow sites for material used to 

 repair the dam. They were designed to help improve fish habitat in this reach of the river. 



METHODS 



Water Ouah'ty 



Water quality samples were collected at the sites listed in Table 1 and shown on Map No. 1 

 (Page A-71 at the end of this report. Several agencies collected samples during the period. Some 

 of the same sites sampled by Spence (1975) were resampled during this study. 



Samples collected by all agencies except the US Geological Survey (USGS) were analyzed at the 

 chemistry laboratory, Department of Health and Environmental Sciences (DHES) in Helena. 

 Samples collected by the USGS were analyzed at their Salt Lake City, Utah laboratory. 



Bottom Fauna 



Bottom fauna samples were collected at two sites on October 2, 1975: (1) Blackfoot River at 

 Pops Place and (2) Blackfoot River at the Flesher Pass road crossing on Highway 279. These two 

 sites were previously sampled by Spence (1975). Three 1 -square-foot samples were collected 

 with a modified Waters round square foot stream bottom sampler (Waters 1961). Samples were 

 preserved in 70% alcohol and sorted in the Department of Fish and Game's pollution control 

 laboratory in Helena. Samples were identified to genera by Robert Newell, Department of Fish 

 and Game, Glendive, MT. 



