WATER RESOURCES 195 
engineering to the well-being of the present and future generations. 
We must try to do several things—put to use water not now used, 
make better use of water now used, and improve the quality of 
water. 
Many possibilities now are being explored to make better use of 
water and to improve its quality. I cannot hope to discuss these 
in any detail, and therefore will content myself witha quick sketch- 
ing of some of the areas of research which hold promise. 
Tremendous quantities of water diverted from streams or reser- 
voirs are not actually used. Tens of thousands of miles of irrigation 
canals, for example, suffer seepage and other losses up to as much 
as one-half the amount of water diverted. A variety of impervious 
linings are being placed in these canals in an endeavor to reduce 
these losses. In the six years ending in 1952, about 25 million 
square yards of linings were placed in more than 750 miles of 
canals and laterals on Federal Reclamation projects, saving an 
estimated 700,000 acre-feet of water annually. The cost of these 
linings is justified by the value of the water saved. 
Excessive weed growth in canals increases losses from seepage 
and transpiration. Experiments with miscible oils led to the de- 
velopment of a plant poison that is toxic in canals but not toxic 
on land. The problem is to kill weeds without killing beneficial 
plants. An aromatic oil that comes out of suspension and evapo- 
rates before the water is diverted to the fields is a partial solution. 
As the cost of water increases, western industry is finding it 
advantageous to plan for maximum practical reuse of water, even 
though the action requires expensive equipment or plant additions. 
Planners in the field of agricultural irrigation are ever more 
taking into account the potentialities of reuse—sometimes re- 
peated reuse of return flows. Water subject to reuse often requires 
improvement in quality. The techniques for improvement vary 
according to whether the purposes are urban, industrial, or agri- 
cultural. 
The Department of the Interior is engaged in a pioneer saline 
water research program. Although the greater public attention 
has been given to conversion of sea water to produce a quality 
acceptable for industrial or even domestic use, the research en- 
