21 
The Waters oe the Rio Grande 
WATER-SOLUBLE IN TWO SAMPLES OF SOIL FROM LA JARA 
Top 2 inches Succeeding 1 4 inches 
Percent 
Percent 
Water-soluble . 
. 3.05 
Water-soluble . 
1.50 
Calcic sulfate . 
. 12.76 
Calcic sulfate . 
30.17 
Magnesic sulfate . . 
...... 2.30 
Magnesic sulfate. 
4.44 
Sodic sulfate . 
Sodic sulfate . 
46.12 
Potassic sulfate . . 
. 0.736 
Potassic sulfate . 
7.29 
This land was occupied by a crop of peas at the time the samples 
were taken. The stand was irregular but the peas were, in the main/ 
fairly thrifty. 
NO RETURN WATERS FROM . SOUTH AND WEST 
I have presented the composition of the drainage, the ground- 
waters, the alkalis and the soil extracts of a section' of the valley ly¬ 
ing south and west of the Rio Grande to a sufficient extent and in 
sufficient detail to support the statement made, that return waters 
from this section cannot, in any considerable quantity, find their way 
into the Rio Grande. The flow of the river is so small (as low as 17 
second-feet at times), while the maximum found at the State Bridge 
in 7 years’ observation, was only 150 second-feet for the month of 
August, that the ground-water would change wholly the character of 
the river-water, which is contrary to what we found in 1908. Fur¬ 
ther, the gaugings carried out under the direction of Prof. Carpenter, 
show a loss about as often as they show a gain. 
s 
This last observation would seem just as applicable to the area 
north and east of the river as to that south and west of it. The condi¬ 
tions north and east of the river are not the same as those obtaining 
south and west of it. If the surface conditions ever were the same, 
which I am inclined to think was the case, at least in the main, in the 
early nineties, say 1894, they are no longer so. 
The character and importance of the results that have followed 
justify a more complete presentation of the facts than I shall be able 
to give. Nevertheless, we can present the big features of these facts 
just as we have done for the section already discussed. 
CONDITIONS NORTH AND EAST OF THE RIVER 
I will digress to justify in a measure the acknowledgement of in¬ 
sufficiency contained in the last sentences which, however, will come 
to light again and again in the following pages. In the first place, the . 
area of the valley mentioned here does not lie wholly within Colorado, 
and is credited with a total area of 900 square miles. The area which 
is discussed probably exceeds 3,300 square miles within which we en¬ 
counter unusual conditions; for instance, practically the whole of this 
