STUDY AREA 



Indian Creek is a small stream with a 

 watershed area of 8.6 square miles. It is con- 

 fluent at the 12-foot tide level with the larger 

 Harris River, which flows into Twelvemile 

 Arm. Pink salmon spawn only in the lower 

 portion of Indian Creek. Median flood flow of 

 this stream has been recorded as 456 c.f.s. 

 and median flow as 3 c.f.s. (James, 1956). 

 Visual estimates of peak abundance of pink 

 salmon ranged from 100 to 16,000 during the 

 years 1950 through 1958 (peak abundance is 

 that time when the most fish are in the 

 stream). 



The valley floor through which Indian Creek 

 flows ascends sharply as it leaves the stream 

 mouth. The sides of the valley are steep in 

 places and heavily wooded, chiefly with Sitka 

 spruce and western hemlock. Although I made 

 no detailed examination of the nature of the 

 valley or of the valley floor, they are prob- 

 ably similar to those of other streams in 

 the area. Zach (1950) reported that many of 

 these watersheds are composed primarily of 

 thin soils over bedrock on steep slopes and 

 waterlogged peat in the muskegs. 



There are two major sources of water to 

 Indian Creek--surface runoff during rains 

 and ground-water seepage during periods of 

 drought. Rain-water is charged with dis- 

 solved oxygen. On its way to the stream, 

 however, as ground water it is subject to a 

 biochemical oxygen demand imposed by the 

 type of aquifer through which it passes. The 

 entire watershed does not contribute a large 

 amount of ground water as the base flow de- 

 creases from approximately 5 c.f.s. 10 days 

 after cessation of rain to 3 c.f.s. 30 days 

 after (James, 1956). 



Although most work was done at the 16- to 

 19-foot tide level, one experiment was done 

 at the 11- to 13-foot tide level. 



EQUIPMENT AND METHODS 



Dissolved oxygen determinations were made 

 on 25-milliliter portions of water that were 

 withdrawn from plastic standpipes driven to 

 specified depths in banks and streambed. 



Water samples were fixed and analyzed at 

 once by the Winkler method (for a descrip- 

 tion of standpipes, method of driving, etc., 

 see McNeil, 1962). 



Vertical and horizontal variation of dis- 

 solved oxygen content of water within the 

 gravel was determined from Latin square 

 and randomized block designs in standpipe 

 placement. 



Water temperatures were measured with 

 a Moeller hand thermometer, a Moeller dial 

 thermometer, and a TRI-R thermistor ther- 

 mometer. Dial and thermistor thermometers 

 were fitted with 6-foot cables so that the 

 sensitive portions of the bulbs could be in- 

 serted into standpipes. 



Ground water was detected and traced by 

 means of its difference from stream water 

 in dissolved oxygen content and temperature. 



Fluorescein dye was used to chart flow 

 directions of water within the gravel of the 

 streambanks, gravel bars, and streambed 

 and to demonstrate interchange of flowing 

 stream water and water within the gravel. 

 Points of origin and emergence of dye-marked 

 water were located with an engineer's transit. 



CHARACTERISTICS OF INDIAN 

 CREEK GROUND WATER 



Ground water extends from the water table 

 down to the first impervious stratum. The 

 migratory behavior of ground water in this 

 surface zone is controlled by local topography 

 and gravity flow characteristics; hence, the 

 general trend of flow under the influence of 

 gravity is into lakes and streams. The rate 

 and direction of flow conform primarily to 

 slopes of the land surface and to the form 

 of the first impervious layer below the water 

 table. (A detailed discussion of ground water 

 is given by Todd (1959) and others.) 



Dissolved Oxygen Content 



The sources of ground water are mainly 

 rain and snow. When rain-water falls upon 

 the ground it is saturated with oxygen at the 



