THE WATER SUPPLY: REGION BETWEEN THE YUBAS. 197 
The Middle and South Yuba rivers run nearly parallel with each other, 
through the gravel region, maintaining a pretty uniform distance of from 
five to six miles apart, but converging rapidly just below North San Juan, and 
uniting about three miles below French Corral, which is the terminal point of 
the gravel range on this divide. The two branches of the Yuba head near 
each other, about thirty-six miles above their junction, oh the crest of the 
Sierra, — a region of granitic rocks, consisting of ridges of moderate height, 
the depressions between which are often occupied by small lakes, or lake-like 
expansions of the streams, where the very numerous branches of the Yuba 
head, offering every possible facility for the collection and storage of water 
on the large scale required for the working of the hydraulic claims situated 
lower down on the divide. The system of ditches and storage reservoirs 
belonging to the “Hureka Lake and Yuba Canal Company,” probably the most 
extensive organization of the kind in California, is fully described in Mr. 
Hague’s pamphlet, reference to which has been made in the note on page 196. 
This company has a system of ditches aggregating about 200 miles in length, 
and three or four storage reservoirs, at an elevation of from 5,600 to 6,600 
feet, which reservoirs are on the head waters of Cation Creek, one of the main 
branches of the South Yuba. Connected with the Eureka Lake ditch, which 
is supplied from these reservoirs, there is another one, called the Miner’s 
ditch, taking its water high up on the South Yuba, and these two ditches are 
so connected that whenever the supply from the river is insufficient, it can 
be supplemented from the reservoirs. The position of these ditches and that 
of the mining localities supplied by them can be seen on the map. In addi- 
tion to the foregoing, there are also several smaller branches or tributary 
ditches, all belonging to the same system, and centring finally at Columbia 
Hill, the principal point of operations of the company owning this water ; 
they working mines on their own account, as well as selling water to other 
parties. From Columbia Hill, the Eureka Lake ditch is continued down the 
divide to French Corral, or to the lowest point occupied by the gravel. 
The possible delivery of water by the ditches centring at Columbia Hill 
is stated by Mr. Hague at 7,500 inches in wet weather, and 3,300 in dry. 
Adding the San Juan ditch, which takes its water from the Middle Yuba, but 
at too low a point to be available except for mines lower than Columbia Hill, 
the total is 8,800 inches in wet weather, and 4,600 in dry. The average 
possible delivery during the year would be 6,700 inches for 300 days; or, in 
round numbers, 2,000,000 inches annually, or about 15,000,000 cubic feet 
