20 BULLETIN 995, U. S. DEPARTMENT OF AGRICULTURE. 
Reservoirs are either individual storage places which supply mois- 
ture for a single farm or part of a farm or they may be community 
enterprises operated by the landowners or by an irrigating company. 
Community reservoirs are sometimes filled directly from permanent 
streams and sometimes they are filled during freshets, while indi- 
vidual reservoirs are frequently supplied with water by pumping; 
in this manner pump irrigation may be direct or indirect. By 
direct irrigation the water is pumped into the ditches or laterals and 
spread at once upon the fields; by indirect irrigation the water is 
pumped into a reservoir, from which it is distributed upon the field 
when needed. There are difficulties to overcome in each of the 
methods of irrigation mentioned. In utilizing water from a com- 
munity reservoir it is necessary for all farmers under the ditch from 
this reservoir to use the water at a time agreed upon by the majority 
of users, regardless of the requirements of all the crops to be watered. 
In case the water is not used by one or more farmers when the reser- 
voir is open, they must await the next opening of the reservoir, which 
may be several weeks later, regardless of the injury that the lack of 
water may cause to their crops. The reservoir can not be opened 
at the will and pleasure of each water user. To do so would cause a 
great waste of water, which is often of greater value than the land 
itself. 
Water from a community reservoir is usually prorated and meas- 
ured to each farmer so that he is able to obtain only his share; like- 
wise, in using water from a stream in which the supply is limited it is 
prorated and measured, and irrigation must cease when the allotted 
number of acre-feet have passed through the gate, regardless of the 
crop requirements. If the pumping plant is a community plant, 
practically the same regulations obtain as in the case of the com- 
munity reservoir; that is, each farmer entitled to water must use 
it at a definite time agreed upon by a majority of the users or for- 
feit his right to the use of the water until the next irrigating period 
arrives. It would, of course, be too expensive to operate the pumping 
plant for a limited number of farmers whose crops were not in need 
of water at the regular irrigating period. The individual plant is 
usually more satisfactory from the standpoint that water may be 
available when needed. The expense, however, of installing and 
operating an individual pumping. plant has frequently been beyond 
the farmer's means. It is apparent, therefore, that the water supply 
for irrigating a sufficiently large area to insure the groAving of the 
necessary acreage of beets to enable a sugar mill to operate success- 
fully is frequently the deciding factor in the growing of sugar beets. 
The problem of water supply should be considered carefully before 
any large sum of money is expended in the erection of a sugar mill 
