46 
It will be noticed from the table that the smaller ditches have a 
much lower duty than the larger ones, and those with reservoirs gen- 
erally show a higher duty than those without. One cause of the low 
duty under the small ditches is that they cover the lowlands lying 
near the river, which, on aceount of their porous subsoil, require more 
water, and which, being generally rough, require a larger volume to 
force the water over the uneven surface. Another cause is that the 
smaller ditches in this district have the older and probably excessive 
decrees, making economy of use unnecessary. With these decrees 
and the poor construction and management of the ditches, it is sur- 
prising that the duty is not lower than shown. 
It is hard to compare the duty under the ditches with and without 
reservoirs, as conditions opposite to the above exist under the ditches 
themselves. Being able to use water when and how it is most bene- 
ficial, the owners feel that economy of use means greater acreage irri- 
gated. Loss, of course, occurs from the reservoirs through seepage 
and evaporation and partially offsets the economy practiced; but as 
this loss is not allowed for in the tables, it would appear that the 
better land irrigated, the better management, better ditches, and more 
economical use not only make up for all loss from the reservoir, but 
leave a large margin besides. 
SEEPAGE. 
Seepage and return water c upies a position secondary only to the 
supply furnished by the ditches and reservoirs. While in volume it 
is small, the regularity and reliability make such waters valuable in 
irrigation out of all proportion to the quantity. Seepage is in part a 
necessary result of irrigation, which can not under any condition be 
remedied; in part a result of the methods, which are theoretical ly 
wrong, but more economical in practical application, and in part the 
result of carelessness and ignorance. 
The application of water to the surface of the ground must result in 
a certain amount percolating through the soil before it is either 
evaporated or taken up by the growing plant, and ultimately finding 
its way to the lower level of the water courses. No piping, cementing 
of canals, or economy of use can avoid this. The value of water and 
the cost of labor determine at what point it is economy to waste the 
one and reduce the other, or to save the one and increase the other. 
In practical irrigating, therefore, it is often economy to use more 
water than necessary in order to reduce the expense of labor in spread- 
ing it on the land, and this excess produces increased seepage. The 
possession of an old and abundant water right does not convey the right 
to use the privilege wastefully and to the harm of others less fortunate. 
In practice, however, it is impossible to prevent this abuse, which is 
