140 IRRIGATION INVESTIGATIONS IN CALIFORNIA. 



The drainage area supplying the works of this company is that of the South 

 Fork of the Yul)a River, elsewhere described in this report (p. 118). There are in 

 this area 17 storage reservoirs. 



The principal reservoir is Lake Fordyce, which has an extent of 474 acres. It 

 is situated on the Noi"th Fork of the South Yuba, 16 miles above the head of the 

 main canal and 6,500 feet above the sea. The dam, built in 1873, in a gorge at the 

 outlet of the Fordyce Valley, was subsequenth- enlarged. It is now 85 feet long, 

 72 feet high on the inside, and 90 feet high on the outside, and 125 feet wide at the 

 base. It is a dry-rock wall, lined on the inside with 3-inch plank, and has a waste- 

 weir 100 feet long and 5 feet deep. It cost $300,000. 



Two miles to the north of Lake Fordj'ce, at an elevation of 7,500 feet, is Meadow 

 Lake, covering an area of 300 acres. The dam forming this reservoir is 1,100 feet 

 long, 40 feet high, and 100 feet wide. Its cost was $75,000. 



Stirling Reservoir is likewise situated above Lake Fordyce and empties into it. 

 Its dam is a rock-filled crib, lined on the inside face with 3-inch plank. It is 200 feet 

 long, 20 feet high, and cost $20,000. 



Lake Spaulding forms at the lower end of this group of reservoirs a distributing 

 reservoir for the entire watershed. This reservoir occupies a broad, deep vallej', the 

 lower end of which is a rocky, narrow gorge. In this, during 1891 and 1892, a drj-- 

 rock dam faced with plank was erected. The dam is 290 feet long, 67 feet high, and 

 67 feet wide; and the outlet is through a tunnel cut through granite. The dam is 

 provided with two wasteweirs, each 120 feet long. The area of the reservoir is 215 

 acres, and the capacity' over 2,000,000,000 gallons. 



Bear Valley Reservoir was formed by building two dams across Bear River. One 

 of these has a height of 35 feet and a length of 140 feet; the height of the other is 15 

 feet and its length 160 feet. The reservoir acts as a distributing reservoir for all the 

 ditches in the Bear River watershed. Its area is 60 acres, and its capacity 145,411.200 

 gallons. It cost $8,000. 



Summit Reservoir has just been finished. It is located in Summit Valley at an 

 elevation of 6,800 feet, and is the highest of the company's reservoirs. It was formed 

 by building a dam 1,580 feet long, with a maximum height of 35 feet. The con- 

 struction of the dam is shown in fig. 4. The area of the reservoir is 400 acres, and 

 its capacity 1,938,816,000 gallons. Its cost was $30,000. 



The South Yuba Canal System. 



The main canal of this system heads in the canyons of the South Fork of Yuba 

 River, three-fourths of a mile below Lake Spaulding. A small timber dam diverts 

 the waters from the canyon through a short tunnel into the head of a 5 by 7 foot 

 wooden flume, which is skillfully built or fastened to the precipitous granite wall of 

 the canyon. This flume terminates in a canal which passes over the low divide at 

 the head of Bear River, and thence in two main canals down the valley of Bear River. 

 The northerly canal pierces the divide and leads back into the Yuba River drainage 

 basin through a tunnel and distributes water to Nevada City, Grass Valley, and other 

 places. The southerly canal supplies Colfax and Auburn and the divide between 

 the Bear and American rivers. The cost of these main canals was $600,000. The 

 locations are sketched on the map which accompanies this report. 



