East Oregonian : E.O. (Pendleton, OR) 1888-current, 1907-08-29

one of the most ideal natural stor-
age reservoirs ever discovered in the
west has been located and fully sur
veyed on Blackfoot river, below the
town of Henry by former City En-
gineer w. A. Samms of Pocatello says
the Tribune of that place, who re-
turned last week with his corps of
assistants and who is now engaged in
the office work of preparing contour
and line maps, profiles and estimates
for submission tn the Indian office at
Washington as a final and definite
step toward construction of the Fort
Hall irrigation system, for which the
federal government has appropriated
$S50,000. Engineer Samms was
awarded the contract by the govern
ment for surveying the reservation,
and spent 66 days in the field. In
conversation with a Tribune man this
morning he told some interesting
facts concerning the work which the
government will shortly undertake to
impound an immense volume of water
for the Fort Hall canal system. The
|
river, the dam being about 10 miles
below the confluence of the Main and
Little Blackfoot. The dam will be
about 1875 feet long and something
like 35 or S6 feet high. This will
back the water of the main Blackfoot
and its smaller tributary up for a
total distance of II miles, the upper
end being within 500 feet of the town
of Henry. The widest part of the inn
mense reservoir will be at the juno
ton of the two rivers. At this point
from north to south the artificial lake
will be nearly seven miles wide and
about 25 feet deep. The extreme
southeast end of the reservoir is with
nabout 10 miles of Soda Springs
: The reservoir is designed to impound
and conserve all the flood waters OF
the two Blackfoot rivers, and OF
John Gray's lake, which will find ties
outlet into Goose creek river through
a canal about two miles long. Goose
creek flows through a big marsh into
the Little Blackfoot river and thence
in the main stream. 1t is estimated
, that the flood waters of the river:
will be sufficient, If impounded in tn,
; reservoir as surveyed, to adequatel,
irrigate all the available land in the
Fort Hall tract.
5 II is the nreSnrt Intention nf tn,
government to raise the water at tn,
dam to the 30-foot level. This viii
impound enough water to cove
e $4,000 acre feet. An acre foot 4
! capable of irrigating two and hal
4 acres of land, so that the stored wate
I will be sufficient to water $1,000
b. acres. This storage capacity is ca
I pable of being supplemented later oil
, by raising the dam and by enhancing
the flow of the two rivers by bringing
down water from Gray's lake.
: The government engineers have de
:. termined that the flow of Blackfoo
river ate the proposed dam site wa
y in 1894 as follows: Minimum, $50 sec
Y. ond feet; maximum, 200 feet; an
r 1904 was normal year. The follow
/, ing year was abnormally dry, and tn
o minimum flow was so second feet an
s the maximum 500 feet 1t has bee
:" estimated by the governments hydro
= graphic surveyors that the run-off o
a overflow of Blackfoot river durin
! 1905, the dry year, was 111,600 acr
:. feet.
= The dam site, according to Enginee
!" Samms, is simply ideal. The Black
'' foot river sweeps down a deep can
yon of lava, narrowing at one poir
to about 100 feet. 1t Is at this poir
that the dam is to be built, backin
81 the water up through the long an
deep canyon to the confluence, an
up to the contour lines of variou
!. smaller tributaries.
While nothing definite is known
the intentions of the government
Al to the time Of beginning constructio
l. of the Fort Hall system, It is conf
o. IDENTIFY believed that dirt will be move
a early next spring