Page:United States Statutes at Large Volume 59 Part 2.djvu/937

 1620 Name of obstruction Description and importance and location Remedial measures 1. Fraser River Hell's Gate Cany< 2. Fraser River Bridge River R: 6 miles above Li] 3. Lillooet River Skookumchuck R 18 miles above 1 son Lake. 4. Chlcootin River Farwell Canyon. 1 from mouth. 5. Ohilko River Keighley Holes 7 above confluel Chilcotin River 6. Quesnel River Rapids 4 miles Likely. 7. Stellako River Falls 4 miles Fraser Lake. 8. Bowron River Gravel bars, mo Bowron River. on Impassable obstruction at cer- tain water levels. Principal spawning grounds of the Fraser system are controlled largely by conditions at this point. apids. Two rapids 900 ft. apart. Uooet. Both serious obstructions to salmon migration below 20 ft. level.' Over % of avail- able spawning area above this point. Formerly bulk of escapement spawned above this obstruction. apids. Rapids in constricted, can- Barri- yon-bound channel. Rec- ords of sockeye delayed from 1 to 21 days. Blockade forms above 1 ft. level on gauge. Commonly inflicts heavy mortality on impor- tant Birkenhead run. 1miles Constricted, bed-rock channel withfallof4to6ft.at obstruction. Blockade above 3 ft. level on gauge. Over 15%of Chilko run" norm- ally lost at this obstacle. miles Channel between high dirt ice of banks. Large boulders in bed cause fall of 5 ft. at ob- struction. Chilko run" delayed at all common water levels. below Obstruction caused by tailings from Boullion mine. Pres- ent channel is constricted by dumped rock so that veloc- ity of flow is too great for normal passage of salmon. above A 3ft. falls located in spawn- ing area is ascended with difficulty. Elimination of obstruction would encour- age extension of spawning area to desirable streams above. uth of At low water stages there is not sufficient water on gravel bars to allow salmon to ascend. Stream INTERNATIONAL AGREEMENTS OTHER THAN TREATIES [59 STAT. APPENDIX B. OBSTRUCTIONS ON THE FRASER RIVER WATERSHED, THE INVESTI- GATION AND IMPROVEMENT OF WHICH IS RECOMMENDED BY THE INTERNATIONAL PACIFIC SALMON FISHERIES COMMISSION Construction of perma- nent fish-ways on each bank at point of ob- struction. Construct fish-ways and improve channel for each rapids on both banks of river. Install fish-way on left bank and alter channel. Include 10 ft. maxi- mum water fluctua- tions. Construct fish-way on left bank. Blast cut in rock on right bank. Cover 6 ft. maximum water fluctuations. Remove boulders and rock debris from chan- nel. Construct baffles on right bank to reduce velocity offlow. Remove rock debris from channel and restore original conditions. Reduce flow in channel. Dredge one main channel for entire flow of river.
 * Hell's Gate gauge.
 * Ohilko run composes over 80% total escapement, 1940-1941.

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