314 FORESTS, RESERVOIRS, AND STREAM FLOW 
agencies. It often happens that public works have a special local im- 
portance in addition to their public value. It is just and proper in 
such cases that local aid be given. This principle is now fully incor- 
porated in river and harbor legislation. For example, the Lake Wash- 
ington Canal, which will be of very great local importance to the City 
of Seattle, is a joint enterprise between the Government and the City, 
the latter paying fully one-third of the cost. The co-operation between 
the U. 8. Geological Survey and the several States in preparing a con- 
tour map of the country is an example on a large scale. The principle 
ought to find an extensive application in the establishment of national 
forests throughout the country. 
ConcLusion. 
This paper will be closed with some reference to the relation of 
navigation to other uses of our streams, and to certain legal obstacles 
that stand in the way of comprehensive measures. That the improve- 
ment of our inland waterways should be organized upon a more 
rational system than it has ever been, that the reciprocal relation 
between navigation, water-power, etc., should be given practical recog- 
nition, above all, that the prosecution of these works should be placed 
upon the same sure basis as is the construction of the Panama Canal, 
with positive assurance that, when once commenced, funds will be 
forthcoming for their prompt completion, would seem to admit of no 
doubt. How far navigation should be correlated, in improvement 
work, with other uses of the streams, is an open question. Water- 
power and navigation are in many cases so closely related that they 
will have to be considered together. In regard to soil wash, no such 
intimate relation exists. To whatever extent soil erosion now ex- 
ceeds that of former times, it relates almost exclusively to cultivation 
and has no appreciable influence upon the channels. Its control is of far 
greater importance to agriculture than it is to navigation. This is 
also true of irrigation, which, so far as it affects navigation at all, 
affects it injJuriously. If the development of irrigation is ever carried 
to the length that we hope it may be, it will cause a heavy drain 
upon the low-water flow of the Missouri, Sacramento, San Joaquin 
and the Columbia Rivers (not important as to this stream), the only 
navigable waterways of consequence that are affected by it. Except 
for this fact of drawing water from the streams, irrigation has no 
relation to navigation. 
