FLOOD05245

• County: Statewide
• Community: State of Colorado
• Stream Name: All
• Basin: Statewide
• Title: Floods of September, 1970 in Arizona, Utah, Colorado, and New Mexico
• Date: 1/1/1978
• Prepared For: State of Colorado
• Prepared By: USGS
• Floodplain - Doc Type: Flood Documentation Report

30

FLOODS OF SEPT. 1970 IN ARIZ.. UTAH, COLO., AND N. MEX.
BUCKEYE, PHOENIX, AND SCOTrSDALE AREAS

Large amounts of rain in the White Tank Mountains caused extensive
flooding in the Buckeye area. About 3 mi (5 km) north of Buckeye, the
Rooseve]t Canal overflowed, and many homes and fields were flooded.
Large sections of the Roosevelt and Buckeye Cana]s were washed away, thus
allowing water to pour into Buckeye. Homes and businesses in Buckeye were
flooded to depths of 3 ft (0.9 m), and many persons were evacuated. The
Buckeye waterplant was flooded, and contamination of city wells was
reported. A cave-in around the casing of a city well left a hole] 5 ft (4.6 m)
deep and large enough to contain a truck, which it did. Railroad tracks were
washed out on both sides of town.
Sheetflow was widespread in Phoenix, where the water generally was
carried by streets that acted as drainage systems; water was 3-4 ft (0.9-].2 m)
deep at some intersections. In places flooding occurred along the north sides
of the Arizona and Grand Canals because of the ponding of water behind the
embankments. Water flowing along the north side of the Arizona Canal
crossed bridges on the canal and flooded areas on the south side (Attebery,
197]); water also overflowed the banks of the canal in several places.
]n Scottsdale more than 250 homes were evacuated because of flooding
when drainage ditches overflowed and irrigation canals were breached. The
main areas of flooding were along Indian Bend Wash, which is a wasteway
for excess water from Arizona Canal, and along Pima Road. A large amount
of water gushed down Pima Road into adjacent homes from a break in the
Arizona CanaL Many homes, trailer parks, and business establishments
along Indian Bend Wash were damaged. About 2,000 ft'l s (57 m'l s) of water
was released into Indian Bend Wash from Arizona Canal (Attebery, ] 971),
and additional inflow increased the discharge to 3,900 fP{s (110 m'{s) at
Thomas Road (fig. 7, No. 125).

NORTHEASTERN ARIZONA

31

o Flagstaff
.70

llP

HOG

.,"
~.,
v'"
EXPLANATION 0\..-~
.66 STREAMFLOW-GAGING STATlON-
N umber corresponds to that in table
6 and in station data

,,"oll"
!d"""

Tuba Cityo

36'

,

69.

35'

Holbrook fCO R.
62 1"'.

NORTHEASTERN ARIZONA

The flooding at Holbrook on September 6 resulted from large flows in the
Puerco River, which joins the Little Colorado River 2 mi (3 km) upstream
from Holbrook (fig. 11). The peak discharge of the Little Colorado River at
Holbrook (fig. II, No. 62) was 19,700 ft 'Is (558 m'/s), which was less than
the peak discharge in 1968 and much less than the maximum of record-
60,000 ft'ls (I,700 m'/s) in September 1923. About 40 homes were flooded
when part of the dike washed out on the south bank of the river, and two
sewage-treatment ponds were washed out on the north side of the river.

Runoff in Chevelon and Clear Creeks came mainly from the tributaries
that head near the Mogollon Rim. ]n a small area on the north side of the
rim, peak flows were comparable to those in the T onto Creek basin, but
rainfall and runoff diminished greatly northward. Peak flows from the upper
reaches of Chevelon and Clear Creeks were reduced by storage in reservoirs,

o 25 MILES
b . " ,', 2\KJlOM~RS

BASE FROM U.S. GEOLOGICAL SURVEY
ARIZONA, 1955, BASE MAP

FIGURE I I.-Location of Oood-determination sites in northeastern Arizona.

and only moderate flows reached the Little Colorado River. Nevertheless,
the Little Colorado River flooded a housing development 2 mi (3 km) north
of Winslow to depths of 2-3 ft (0.6-0.9 m).
Dinnebito, Oraibi, and Wepo Washes, which drain into the Little
Colorado River from Black Mesa, had extremely high peak discharges,
which caused severe erosion in places (table 3). Wepo Wash flows through a