COLORADO IRRIGATION WATERS 
AND THEIR CHANGES. 
BY Wm. P. Headden. 
§ i. The irrigation waters used in this State are largely fur¬ 
nished by the melting of the snows which accumulate in the high¬ 
er portions of the mountains during the latter part of autumn, 
winter, and early spring. The springs feeding our streams are for 
the most part such as owe their waters to the same source, and are 
simply the reappearance of these waters retained by the valley soils, 
which are for the most part shallow and store but a small amount 
of water, the most of it being free to come down early in the sea¬ 
son, before the middle of July. 
§ 2. Our rivers do not descend very far into the plains before 
their waters are diverted from their natural courses, either to be 
stored or used immediately for the purposes of irrigation. The 
water supply is becoming a question of such importance and com¬ 
mands so high a price that large expenditures are being made to 
prevent the storm and flood waters from going to waste by running 
down to lower levels. 
§ 3. The simple diversion of the waters from their natural 
courses does not change their character provided the character of 
the course is not changed. This, however, is not the case. These 
waters flow but short distances through mountainous and sparsely 
populated sections of country, where the water entering them from 
the adjacent country is of the same character as that of the stream it¬ 
self. The collecting grounds are for the most part covered with a 
thin granitic soil bearing some forest and other mountain vegeta¬ 
tion; but a very considerable area consists of naked schists and 
granites. The lower portions of these streams usually flow through 
fertile valleys, often under cultivation. The waters are sometimes 
diverted in the higher portions of their courses and at every point 
below this where their volume and the contour of the country will 
permit. 
§ 4. The Cache a la Poudre river flows for the first fifty miles 
of its course over bowlders of schist and granite, and then over 
gravel and sand of the same character. The North Pork flows for 
a portion of its course through jura-triassic strata, into which it 
has cut its bed before emptying into the Poudre. The chief for¬ 
eign constituents, that is other than those dissolved out of the rocks 
