36 BULLETIN 614, U. S. DEPARTMENT OF AGRICULTURE. 
In the North Yakima district the principal sources of water supply 
for irrigation are the Naches River and Cowiche Creek. The water 
is brought to various parts of the district through canals or ditches, 
from which it is led through open ditches to the individual ranches, 
where it is distributed through the orchards by means of furrows. 
(See Pl. VI.) 
Private pipe lines for the purpose of conserving as much water 
as possible have been installed in some instances by individual 
growers, particularly on the higher lands in the Nob Hill district, 
and there is a growing tendency on the part of the ranchers in the 
North Yakima district to follow this custom. This practice has 
nothing to do with the general maintenance of the canal as a whole, 
and the expense, which obviously will vary greatly, is borne entirely 
by the individual owners. In this study such an investment is 
considered as part of the land and improvement value. 
The basis of water distribution under the different ditches varies 
from 33 to 80 acres per second-foot, and all stockholders under a 
given canal pay exactly the same assessments for the same amount 
of water. In some instances growers May use less water per acre 
than usual on a larger amount of lJand—that is, one-half inch (miner’s) 
per acre instead of 1 inch per acre. This, however, is the excep- 
tion. The customary rate of distribution is as given above in the 
second-foot. 
In the Zillah district the majority of ranchers receinee their 
supply of irrigation water through a Government canal, known 
locally as the Sunnyside Canal. The water is delivered fans the 
main ditch through open ditches or wooden flumes to the ranches. 
Flumes are often used in the orchards and usually are placed along 
the higher parts or ridges of the land so that the water may be dis- 
tributed more easily throughout the orchard. 
These flumes in the orchard are temporary and can be removed 
to permit cultivation or other orchard operations. Usually they 
are made of 8- to 12-inch boards, 4 to 1 inch thick, and of varying 
lengths. Along these boxlike forms or flumes holes are made through 
which the water is allowed to flow for distribution. These holes 
usually are covered with a small piece of tin or lath, which is used to 
regulate the flow of water. There is a tendency in some instances 
in this district to substitute underground piping for open ditches 
and flumes. The water in both the North Yakima and Zillah dis- 
tricts is distributed through the orchard by means of furrows. Very 
few orchardists in the valley practice the flooding method. 
The maintenance charge or water tax May vary greatly from year 
to year. Often high assessments are made for permanent improve- 
ments or to cover the expense of litigation. The ranchers in the 
North Yakima district from whom data were obtained paid annually 
