"November, 1930. The average discharge for 21 years was 116 c.f.s. 

 The water temperature at the time of the survey ranged from 7U°F. 

 near the mouth to 59°F. in the headwaters. 



There were 19 dams on the main stream, 11 of which were 

 at least barriers at low water stages, and several of these partially 

 obstructed the passage of salmon even at high water. There were 29 

 water diversions on the main stream, of which only one, the intake 

 to the hatchery of the Oregon State Game Commission, was actually 

 screened. The only other screen was a grizzly with 1-inch spacing 

 at the intake to the flour mill in the town of Union, 



There are several factors that have made conditions in 

 Catherine Creek unfavorable for the production of anadromous fish. 

 The first and most important of these is the effect of the dams and 

 water diversions previously mentioned. While the dams might be pro- 

 vided with fishways and the diversions screened, the extensive with- 

 drawal of water for irrigation, industrial, and domestic use cannot 

 be avoided. This often does not leave a sufficient volume of flow in 

 the stream bed at the time of the upstream migration of salmon. Second , 

 the water temperature becomes abnormally high in late summer, often 

 above 80 F, Such temperatures are not conducive to the successful 

 propagation of salmon or trout. It was reported that for this reason 

 fish could not be held at the state trout hatchery later than the 

 month of June, These high temperatures are due to the exposure of 

 the stream bed resulting from water diversions, and the removal of 

 timber in the headwaters. Third , flash floods have become increas- 

 ingly frequent occurrences. For example, on August 19, 19U1, a 

 cloudburst on the middle fork brought down a sudden $-foot high flood 

 of thick, muddy water. A local resident reported that when the crest 

 had passed he counted Uo dead adult salmon in a half-mile section of 

 the stream bordering his ranch. Such occurrences are also very damag- 

 ing to salmon and trout eggs and fry. These excessive floods are due 

 mainly to the removal of timber in the upper section of the watershed. 

 Under these conditions the stream is of little value in the production 

 of salmon* 



The former good run of chinook salmon into Catherine Creek 

 has been greatly depleted. Twenty salmon spawners were counted during 

 the survey, but visibility was poor due to the turbidity of the water. 

 The run of steelhead trout has maintained itself much better, a fair 

 run of this species still ascending to the headwaters during the spring 

 high water stages. 



13CC-(1). Mill Creek . — (August 13, 19Ulj Frey and Bryant.) 

 Mill Creek has two outlets; one discharging directly into the Grande 

 Ronde River, and the other discharging into Catherine Creek at a point 

 1 mile above the mouth. It is normally a small stream, about 10 miles 

 long, and flows through a highly cultivated region. The gradient is 

 slight in the lower section, and the lower 3^ miles of the stream bed 



51 



