newell.] RIO GRANDE, COLORADO. 41 
RIO GRANDE BASIN, IN COLORADO, NEW MEXICO, AND TEXAS. 
This drainage basin has been described in some detail in the Twelfth 
Annual lleport, Part II, Irrigation, pages 240-290. A number of the 
river stations located in 1889 have been maintained, while others have 
been established during 1894. The problems along this river are 
largely interstate or international in character, the development of 
agriculture by irrigation in Colorado tending to reduce the amount of 
water available in New Mexico, and the increased use in New Mexico 
and Colorado apparently resulting in a diminished flow at points where 
irrigating canals in Texas and in the .Republic of Mexico have been 
accustomed to take their supply. Eecords of river flow have been 
maintained under difficulties, the principal of which was the lack of 
funds sufficient to induce observers to continue unbroken series of read- 
ings, and because of the impossibility of inspecting the gages and 
making check measurements at necessary times. 
Measurements and observations were first begun in the vicinity of 
Del Norte in 1889, by Mr. George T. Quinby. The object of the meas- 
urements was to obtain the flow of the river before water was diverted 
for the agricultural region of the San Luis Valley, and, by a compari- 
son of this with the figures obtained at Embudo, to acquire data as to 
the effect of the numerous ditches taking out water between the two 
points. The river 25 miles above Del Norte flows out of the canyon 
at Wagon Wheel Gap. Little water, however, is diverted until the 
edge of the San Luis Valley is reached, the largest canal heading near 
the town of Del Norte. During freshets the river divides into a num- 
ber of channels, making it difficult to obtain measurements near town. 
In order to avoid the expense of establishing a station during time of 
high water, the first measurements — those about June 1 — were made 
from several bridges crossing the numerous branches. The results 
were not wholly satisfactory, and on June 25 a station was established 
above the branches. Later a locality about 2 miles farther up was 
chosen. Observations at this point were kept continuously from Sep- 
tember, 1889. 
The station is above all the irrigating ditches of importance. The 
river flows in one channel, about 175 feet wide and of very regular 
section. The banks on each side are steep, and the water is reported 
never to overflow. The course of the stream is straight for several 
hundred yards both above and below the section. An inclined gage 
is set, at an angle of about 30° to the horizontal, on the left bank, and 
is referred to bench marks. As noted on October 10, 1891, No. 1 is a 
large nail in the root of a tree 15 feet northwest of the end of the 
cable on left bank of river. Bench mark No. 2 is a large nail in the 
