172 
LINING OF DITCHES AND RESERVOIRS TO PREVENT 
SEEPAGE LOSSES* 
In a recent bulletin of the California Station E. Mead and B. 
A. Etcheverrv call attention anew to 'the enormous waste of irri- 
gation water due to seepage from ditches and reservoirs. They 
show from general observation and from a large number of care- 
ful measurements that "the water which sinks into the soil from 
ditches and reservoirs is one of the chief sources of waste in irri- 
gation. In gravelly soils, or where ditches cross gypsum strata, 
the losses sometimes amount to more than half the total flow." 
Measurements made on a large number of ditches in the course 
of the cooperative irrigation investigations of the Office of Ex- 
periment Station and the California Station "show an average loss 
on main canals of about i per cent, for each mile that water is 
carried; on laterals the loss amounted to between n and 12 per 
cent, per mile : while on some California canals the loss in a single 
mile was 64 per cent. * * * Measurements made in 1906 on 
a storage reservoir having a surface of 10,000 square feet showed 
a seepage loss of 1,000 cubic feet per day. The reservoir is 
filled by a windmill, and this loss was 10 per cent, of the average 
quantity pumped each day — a loss top heavy to be borne. The 
problem of this reservoir owner is the problem of hundreds of 
irrigators. * * * 
"The water which escapes is often worse than wasted. It col- 
lects in the lower lands, fills the soil, drowns the roots of trees 
and plants, brings alkali to the surface, and is a prolific breeding 
place for mosquitoes." 
In the course of the same investigations attempts were made to 
find practical means of lining storage works and canals and 
ditches to prevent or at least to reduce this waste and consequent 
loss. "From the results obtained the conclusion was reached that 
on large and costly aqueducts or important storage works, linings 
of cement, concrete, or asphaltum may be employed without the 
expense being prohibitive." It is pointed out, however, that a 
very large proportion of the irrigation of the country is done by 
means of the smaller, cheaper reservoirs and other works, the 
owners of which "can not afford the expense needed to line the 
reservoir with concrete or asphalt because the value of the water 
stored will not justify this expense." 
In view of the fact that the greater proportion of the losses 
occur on lateral ditches and small storage basins, it is necessary to 
find some simpler and cheaper, but efficient, lining which can be 
applied by farmers and unskilled laborers. It is clear that the . 
general use of such a method would result in a great improve- 
* Compiled from California Station Bulletin 188. 
