FARM ORGANIZATION IN SOUTHERN ARIZONA, 7 
Tonto Creek with the Salt River was begun. Water rights were 
again adjudicated and the lands of the valley were divided into three 
classes based on priority of water right. Lands in class A have 
prior rights to a certain amount of water known as the "normal 
flow" of the river, and in addition have an equal right in water (hat 
may be stored in the reservoir, (lass B lands have prior rights to 
a certain amount of flood water, in other words, a certain amount 
of the flow of the river which is above the normal flow, and in addi- 
tion have equal rights in stored water. Class C lands have any flood 
waters not appropriated to class B lands, and in addition equal 
rights with all lands in stored water. These rights may be stated 
more briefly by saying that all lands have equal rights in water 
stored in the reservoir, but in addition Class A lands are entitled 
to all the normal flow of the river, and when the river flow is at a 
flood stage the flood water goes to lands in classes B and C. In 
addition to these general differences in water rights, there are differ- 
ences in priority of right among the lands in each of the three different 
classes. When there is a good normal flow in the river, lands in 
class A may be abundantly supplied from that source and may save 
their stored water until the end of the season, or until the normal 
flow drops so low that they are compelled to draw upon it, while 
lands in classes B and C may be compelled to rely upon stored water 
during the whole season. Any stored water remaining unused at the 
end of the season reverts to the general fund, and is reapportioned 
equally among all water users at the beginning of the next year. 
The Roosevelt Dam was completed in 1912 and stored water 
delivered for the first time during that year. The reservoir was not 
over half full at this time, and during the season of 1914 the supply 
of water had run so low that several thousand acres of land in classes 
A and B did not receive sufficient water to meet the requirements of 
the crops upon them. Considerable loss to the owners resulted. In 
April, 1915, the reservoir was filled for the first time, and water ran 
over the spillway. It overflowed again early in 1916. Careful esti- 
mates based upon a long series of annual measurements of the river 
flow indicate that with the reservoir full of water the chances are 
that a shortage will not occur more than once in 21 years. 1 
The capacity of this reservoir is 1,367,600 acre-feet of water and 
187,000 acres of land will share in its stored supply. In addition 
to these lands there are approximately 20,000 acres under the Tempe 
Canal which have rights in the normal flow of the river, but no rights 
in the stored water of the reservoir. They are not required to 
share in the cost of the reclamation project. 
The cost of the project is assessed against the land and constitutes 
a lien upon it. The owners of the land will have 20 years from the 
* Office of Experiment Stations, U. S. D. A. Bull. 235, p. 44. 
32657°— 18— Bull. 654 2 
