ON THE MEASUREMENT AND DIVISION OF WATER* 
By L. G. CARPENTER! 
Questions concerning the measurement and division of water 
probably give rise to more trouble than all other questions com¬ 
bined in an irrigated country. While frequently the amount of water 
in dispute is small it may be and often is, a serious matter. It cer¬ 
tainly is a source of irritation, causing constant friction between 
the management of a canal and the consumers, and between neigh¬ 
bors. It is more troublesome because of the well-known fact that 
a stream of water always looks larger in the neighbor’s ditch than 
in one’s own. It is irritating because neither disputant can con¬ 
vince his opponent or even satisfy himself, and hence for the lack 
of knowledge of how to determine the fact, assertion takes the 
place of demonstration. A more widely distributed knowledge of 
methods will remove much of these troubles, as it already has. 
When the water supply is scanty, error may be a very serious 
matter, for the crops of the user may depend on a small 
quantity of water, and gives cause for strenuous dispute. This has 
been the case from time immemorial and the serious disputes thus 
arising are embalmed in a curious manner in one of our words in 
■common use. In old Roman times, an artificial water channel, 
therefore a ditch, was a “rivus,” and the users from such a water 
course were “rivalsand the conflict in interest indicated in this 
word, comes from the typical case of users from the same irrigation 
ditch. This same difference in interests persists today as it did 
at the time when their disputes became notoriously difficult of 
settlement. 
The problem of a just distribution of water is therefore one 
of the most important, as well as one of the most difficult problems 
of canal management. Frequently, in fact generally, the measure¬ 
ment becomes one of approximation. The practical need is to 
obtain a method that is sufficiently exact for the given conditions 
and also—which is sometimes of greater practical importance—to 
secure one which will inspire confidence. 
The measurement of water and the division of water may be 
two distinct though closely related problems, so that a method 
which is intended for measurement serves also for division. It 
should be clearly understood that no one method will apply to all 
situations. Methods suitable to a canal of heavy fall and with a 
heavy fall in the laterals, cannot be available where the fall is 
*The first edition of this bulletin was issued in October, 1890, a 
reprint in July, 1891. The third edition, with additional tables and 
considerable revision, was issued as Bulletin 27 in 1894. The trapezoidal 
weir first described in the early editions of this bulletin has been very 
widely adopted on the American continent. 
1738-740 Equitable Building, Denver. 
