The Caldwell tribune. [volume] (Caldwell, Idaho Territory [Idaho]) 1883-1928, 1916-02-04
CONSULTING ENGINEER
MAKES REPORT ON SITE
Wiley Reports on Power Possibilities
of Arrowrock.
(Homedale Press.l

(Homedale PreSs.)
A. ]. Wiley. who has been employ
ed as consulting engineer by the Gem
district for the purpose of investigat
ing the feasibility of building q
power plant on the Boise river, neal
the Arrowrock dam, made the follow
ing preliminary report some few
weeks ago:
Amount of Power.
There are two dam sites under con.
sideration. one short distance below
the Highland dam and the other about
mile further down the river. Al
the first site, it is feasible to build a
dam giving a head of IS feet, and at
second site, a head of As feet can be
obtained. AT the first site, with the
probable amount of water that will
be available at the peak of the irri-
cation season, about 1900 electrical
horse power can be developed, and at
the lower site, about $4,000 electrical
horse power. There will be smaller
amount at the beginning and end of
the season but at all times the power
will be in proportion to the irrigation
needs considering 1900 to 1900 horse
power as being the amount needed at
the time Of greatest demand. Outside
of the irrigation season, the amount of
power will depend upon factors that
are too uncertain to estimate upon at
this time but it will be small, probably
between 1000 to 1000 electrical horse
power for the upper site and 500 to
5000 for the lower site.
Availability of Sites.
Either of the sites, taken in con-
junction with their location immed-
lately below the Arrowrock dam, Of
fers an exceptional chance for cheap
development and power production.
The control of the river by the Arrow
rock insures the most favorable condi-
tons for construction as the prob
lem of flood control in the founda-
ton work will be eliminated. The
action of sand upon the water wheels
will be prevented by the deposit of all
materials carried by the river in the
still water of the great reservoir.
The principal value of the Arrow
rock reservoir to the power sites,
however, is that it insures an ample
supply Of water just at it is required
to develop the power for irrigation
pumping, the water being let out of
the reservoir as it is needed to sup
ply tHc lTTlBdtlOn demand upon tract
similar in location and requirements
to the district upon which the water
it to be pumped.
Both sites, but particularly the low
er one, offer a good opportunity for
cheap development, there being solid
rock to connect with at each end and
a compact gravel formation upon
which to found the dam and power
house.
The lower dam site is apparently
the more favorable, there being width
enough at this point to build the
power house as a part of the dam,
thus insuring the most favorable
operating conditions and the minimum
of cost.
Since the above preliminary report
was made detailed surveys of the two
dam sites, general survey of the back
water contour and test pits and tun-
nels for the location of bed rock have
been completed. Detailed plans and
estimates are being prepared and will
soon be completed. From prelimin-
airy estimates, checked by actual cost
upon similar work, the cost OF de-
velopment at the lower dam site will
not exceed $1,000 per electrical horse
power measured at the switchboard of