8 BULLETIN 913. r. S. DEPARTMENT OF AGRICrXTURE. 
mentary and the physical evidence of the value of the right to be 
purchased, giving, perhaps, more attention to the latter than to the 
former. 
RIGHTS TO UNDERGROUND WATERS.? 
Though most farmers who settle on irrigated land obtain rights 
through organizations of some kind rather than direct from streams, 
there is large opportunity for individuals to obtain independent sup- 
plies of water from underground sources through veils. 
With relation to the nature of rights to their use. underground 
waters are divided into four classes: (1) Underground streams 
flowing in known and defined channels: (2) underground streams 
flowing in unknown and undefined channels : (3) artesian waters : and 
(-4) percolating waters. While these classes are distinct in law. it is 
not always easy to tell to which class a particular supply belongs. 
In fact, water which has long been considered in one class may be 
found to be in another class, and thus subject to a different law. 
Subterranean streams flowing in known and defined channels are 
subject to the same laws as surface streams — that is. in most States, 
to appropriation rights — and one may not take water from such 
a stream by means of wells or other means if it interferes with the 
rights of prior appropriators. Ownership of the land on which a 
well is located does not give any right if the water is. in fact, a part 
of the stream. 
But if a well draws water from an underground stream whose 
channel is unknown and undefined, the ownership of land carries 
with it the right to take the water. It is clear that the channel of 
such a stream may become known as a result of investigation, in 
which case the stream will become subject to the law of appropria- 
tion, and the prior users may stop the use by later appropriators. 
Artesian water — that which is under pressure within the ground, 
so that it will rise in the well to or toward the ground surface — is 
held to belong to all the land overlying the artesian basin, and each 
owner of such land is permitted to make any reasonable use of the 
water which will not interfere with a like use by all the other land- 
owners. In this respect rights to artesian waters are similar to 
riparian rights on streams — they are not fixed and definite, but 
depend upon the total supply and the total demand by all owners 
of land overlying an artesian basin. Since the water is the common 
property of many owners, it is subject to public control, and most 
of the States have more or less legislation on the subject. 
Percolating water — that is. water moving through the soil, but not 
under pressure and not confined to a known and denned channel — 
: This discussion is based on Kinney's " Law of Irrigation and Water Eights." second 
edition, San Francisco, 1912. 
