64 
PROGRESS REPORT, HYDROGRAPHY, 1893 AND 1894. [bull. 131. 
IDAHO FALLS STATION, ON SNAKE RIVER. 
This station is situated about 2 miles below the town of Idaho Falls, 
formerly known as " Eagle Kock." At the town the river flows 
through a narrow gorge in the lava, forming whirlpools, and having a 
velocity so great that current-meter measurements can not be made. 
Below the railroad bridge, however, it begins to widen, and finally 
spreads over a broad, gravelly channel, being confined by high banks 
on both sides. Accurate measurements can be made in low water, and 
fair results can probably be obtained during flood by means of suitable 
apparatus. The gage is on the right-hand side of the left bank of the 
stream, and is a short distance below the house of Mr. E. J. Wilson. 
It has an inclination of about 30°, and the graduation extends up to 
12.5 feet. It is made of 2 by 4 inch scantling, nailed to stakes firmly 
driven into the river bed and bank. The bench mark is a spike driven 
into a large cedar tree, formerly used as one of the supports of the 
cable. The 2.3 mark of the gage is 9.60 feet below this bench mark. 
This station was established by Mr. L. D. Hopson and readings begun 
on July 1, 1889. It was inspected by Mr. Arthur P. Davis on October 
3, 1894, but measurements of discharge could not be made nntil a cable 
was placed in position. A measurement was made at the wagon bridge 
at Blackfoot, but the conditions there are not favorable for accurate 
results. The main current is diagonal to the direction of the channel, 
and there are numerous small eddies and points where the water is 
apparently still. Four large piers obstruct the channel, thus compli- 
cating the measurements. The maximum velocity was found to be 
about 6 feet per second, and the depth, 12 feet. The total discharge at 
this point on November 1, 1894, was estimated to be 8,040 second-feet. 
The following rating table was constructed from measurements made 
during preceding years, but has not been verified by recent measure- 
ments • 
Rating tabic of Snake Fiver at Idaho Falls, Idaho. 
Gage 
height. 
Dis- 
Gage 
Dis- 
Gage 
Dis- 
Gage 
height. 
Dis- 
Gage 
Dis- 
charge. 
height. 
charge. 
height. 
charge. 
charge. 
height. 
charge. 
Sec. feet. 
Sec. feet. 
Sec. feet. 
Sec. feet. 
Sec. feet. 
1.00 
1.500 
3.00 
5,100 
5.00 
11,450 ! 
7.00 
21, 500 
9.00 
37, 900 
1.10 
1,600 
3.10 
5,375 
5.10 
11, 875 
7.10 
22, 150 
9.10 
38, 900 
1.20 
1,700 
3.20 
5, 650 
5.20 
12, 300 
7.20 
22, 800 
9.20 
40, 000 
1.30 
1, 825 
3.30 
5, 950 
' 5.30 
12, 750 : 
7.30 
23, 500 
9.30 
41, 100 
1.40 
1,950 1 
3.40 
6,250 
5.40 
13, 200 
7.40 
24, 200 
9.40 
42, 200 
1.50 
2,100 : 
3.50 
6,550 
5.50 
13, 650 
7.50 
24, 925 
9.50 
43, 300 
1.60 
2,250 
3.60 
6,850 
5.60 
14, 100 1 
7.60 
25, 650 
9.60 
44, 400 
1.70 
2,400 i 
3.70 
7,150 
5.70 
14,550 
7.70 
26, 425 
9.70 
45, 500 
1.80 
2,550 
3.80 
7.450 
5.80 
15. 000 i 
7.80 
27, 200 
9.80 
46. 600 
1.90 
2,725 ! 
3.90 
7.750 
5.90 
15, 450 
7.90 
28, 000 
9.90 
47, 700 
2. 00 
2. 000 
4.00 
8,050 
6.00 
15,900 1 
8.00 
28, 800 
10.00 
48, 800 
2.10 
3, 100 
4.10 
8, 350 
6.10 
16. 400 
8.10 
29, 675 
10.10 
49. 900 
2.20 
3,300 \ 
4.20 
8, 650 
6.20 
16, 900 
8.20 
30, 550 
10.20 
51, 000 
2.30 
3, 500 
4.30 
8,975 
6.30 
17, 450 
8.30 
31,425 
10.30 
52, 100 
2.40 
3,700 
4.40 
9,300 
6.40 
18, 000 
8.40 
32,300 
10.40 
53, 200 
2.50 
3,900 
4.50 
9, 650 
6.50 
18, 575 
8.50 
33,225 
10.50 
54, 300 
2.60 
4,100 
4.60 
10, 000 
6.60 
19, 150 
8.60 
34, 150 
10'. 60 
55, 400 
2.70 
4,350 
4.70 
10, 350 
6.70 
19, 725 
8.70 
35, 075 
10.70 
56, 500 
2.80 
4, 600 
4.80 
10, 700 
6.80 
20, 300 
8.80 
36, 000 
10.80 
57, 600 
2.90 
4,850 
4.90 
11, 075 
6.90 
20, 900 
8.90 
36. 950 
10.90 
58, 7 00 
