The border vidette., 1930-03-08
DAM AND SAN CAR
LOS PROJECT

Former President Calvin Cool.
idee. on Tuesday, March 4, at
2:3O p. m.. dedicated Coolidge
Dam at San Carlos, Arizona, on
the Gila River. The huge struc
ture is the only multiple dome
type dam in the world and com
pares favorably in size and i'm
portance with the famous Roose
welt Dam, which is only about
fifty miles distant.
| Coolidge Dam will enable the
irrigation of 100000 acres of
agricultural lands in the Flor.
ence- Grapde Valley, some
seventy-five miles downstream.
Half of these lands will be farm,
ed by Pima indians and the re.
mainder by white farmers.
| Additional dams on the Gila,
pumping of subterranean flows,
and water conservation systems
are expected to increase the
farming acreage to more than
200, 900.
| Following are some interest
ing data concerning the new
dam:
| Elevation of the top of the
dam above sea level, 1855 feet.
| Height of dam above stream
bed, 220 feet.
| Thickness of domes at bottom.
| 81 feet.
Thickness of domes at top,
| 4 feet.
Area of land submerged, %,
1000 feet.
| Reservoir length, % miles.
| Reservoir capacity, 1900, 900
acre feet.
! Annual rupoff of the Gila
River, 385, 900 feet.
| Concrete in dam, 205,0 Gu.
yards.
| Steel (reinforcing) $500 tons.
Rock and gravel excavation,
28O, 900 cubic yards.
San acre. foot of water has a
volume equivalent to a depth of
lone foot extended over an area
| of one acre.
The land to be irrigated by
the Coolidge Dam. like many
other places in the Southwest.
has been inhabited from pre-
historic times. Well defined evi
dences of pre- historic develop
ment, including irrigation. are
to be found in a number of locali
ties. The we'll : known Casa
Grande Ruins, ancient canals
nearby and number of lesser
known ruins are scattered over
q wide area. They prove con.
clusively that the whole drain
age area of the Gila was inhabit
ed by an agricultural people of a
homogeneous and advanced state
of culture. Some difference of
opinion arises, however, as to
the ancestral relationship be
tween these ancient races and
our present. day Pimas of the
Gila River Reservation.
| Mr.. F. w. Fewkes of the AS
sociated Bureau of Entomology.
made extensive Investigations
and concludes that these ancient
dwellers were the fore bearers
of the present day Pima Indians.
He believes that the Pima name
"Hohokum" may be adopted to
designate this ancestral stock to
whom can be ascribed the erec
ted the erection of the Casa
! Grande on the Gila. In the
course of time hostile portion,
bent on plllage. came into this
section from the east or west
and either drove the agricultur.
alists out of their Casa Grandes.
or at least broke up the custom
of building such extensive struc
lures.
| Other authorities take the view
that these ancients were of a
different race entirely, and that
the Pimas in accordance with
some of their traditions came at
later time and either drove out
the early inhabitants or simply
occupied the country that the
former race abandoned.
However that may be, we
know from historical accounts
that the Casa Grande ruins and
the Pimas themselves were much
the same as they are today as
when the Spanish missionaries
from old Mexico, ventured into
this, their so-called "Pinera
Alta" country as early as 1889.
It. Is generally believed that
the route of Fray Marcos de
| - 10 Ljool> y@ko~