The Coconino sun., 1924-08-22

it would not be feasible to build a dam
to raise the water higher than eleva-
tion 1750 feet above sea evel.
So far as the rock structure is con-
cened, it would be feasible to build
dam at Bridge Canyon to raise the
water to the 1000 foot level. The
next problem is that of determining
the best route for canal or conduit
leading from Bridge Canyon to the
Williams River reservoir site.
1t has been suggested that an open
canal may be constructed from the
diversion dam, following a bench
which is supposed to exist in the lower
part of the Grand Canyon. This is the
so-called Tonto Platform, which | fol-
lowed on foot for some distance in the
vicinity of Diamond Creek. / under
stand that at one time an Indian trail
followed this platform from diamond
Creek to Spencer Canyon. However
at some places the trail followed along
the almost vertical walls. The So
called Tonto Platform is cut by many
side canyons and disappears alto
gether few miles below Spencer Cam
yon. The Tonto Platform, whore it
exists, is in the Bright Angel shale
formation, which is entirely .unsuit-
able material in which to locate a
canal / might add further that a
canal must be constructed on uni
form grade, while the grade of the
so-called bench or platform is far
from uniform. Due to faulting, the
bench in some places drops 100 feet
or more; at other places it may raise
that distance, and few miles below
Devils Slide the platform dips down
into the river.
In order to determine the accesi-
bility of Bridge Canyon dam site, /
made another field trip in May of this
year. A plain table survey was made
to determine the feasibility of build
ing a railroad to this dam site. While
on this work, | visited the rim of the
Grand Canyon at various places be-
low Bridge Canyon. AS a result OF
this trip, | obtained a good view Of
practically all of the canyon from a
point few miles above Pierce's Ferry
to Bridge Canyon. After completing
examination, l became thoroughly con-
vinced of the impracticability of con-
structing an open canal, of the size
necessary for the irrigation of two
million acres, leading from a dam
located in the Grand Canyon at any
point above Pierce's Ferry.
/ have called attention to the canal
route investigated by the Arizona En-
gineering Commission, reference being
made to the one diverted at
Virgin Canyon at elevation 1880 feet
above sea level If canal were to
be taken out at Bridge Canyon on the
200 foot level, it would simply parallel
the canal just referred to, excepting
that its elevation would be about $50
feet higher. The elevation being too
great toward the east, it would be
necessary for such a canal to follow
the west slope of the Black Mountain
range. ! am thoroughly familiar with
the character of the Black Mountain
range, and can state positively that
if canal were constructed at an ele-
walton $50 feet higher than the one
described in the report of the Arizona
Engineering Commission, such canal
would be higher on the slope of the
mountains and would be more expen-
sive. In my opinion the so-called
High Line Canal, diverting from
Bridge Canyon at elevation 1000 feet
above sea level, would cost more than
six hundred million dollars, if con-