WSP00684

• File Number: 8220.101.16
• Description: Glen Canyon Dam/Lake Powell
• State: AZ
• Basin: Colorado Mainstem
• Date: 1/1/2000
• Author: Webb et al.
• Title: Sediment Delivery by Ungaged Tributaries of the Colorado River in Grand Canyon Arizona
• Water Supply Pro - Doc Type: Report/Study

Table 11. Estimated or measured sand content of streamflow entering the Colorado River in Grand Canyon,
Arizona.

Slleor PARTICLE SIZE
Trlbulary gaging slallon Sand (%) SIII.Clay (%) Source
General na 15 85 Randle and Pemberton (1987)
Little Colorado River near mouth 0.7-22.6 77.4-99.3 GalTett and others (1993)
I-50 50,99 Rote and others (1997)
Bright Angel Creek . near mouth t87 \3 GalTett and others (1993)
near Grand Canyon 1-64 36-99 Rote and others (1997)
Kanab Creek neaT Fredonia 0.1-4.5 85.5-99.9 Garrett and others (1993)
above the mouth 0-36 64-100 Rote and others (1997)
Havasu Creek above the mouth 1-89 11-99 Rote and others (1997)
National Canyon . near mouth t8J-99 1-19 GalTett and others (993)
Ungaged tributaries! various 30-100 8-10 collected hy the authors

. not a gaging station, miscellaneous tributary flow in 1983 (Garren and others, 1993)
t calculared rrom silt+clay% and assuming no particles> 2 mm ~re uansported
~ 89 streamflow deposits in 21 ungaged tribuWies sampled by the authol'5 (fig. 10)
nB, nol applicable

Table 12. Sand delivery by streamflow from ungaged tributaries of the Colorado River in Grand Canyon,
Arizona.

Sedlmenl SAND YIELD" (lOa Ml//yr)
-yield Data regression equation Renard (1972) equallon
relch River miles 150.. 50% 75% 15% 50% 75%
A -15.5toO.9 0.010 0.032 0.049 0.011 0.038 0.057
B 0.9 to 61.5 0.092 0.305 0.458 0.089 0.297 0.445
C 61.5 to 87.8 0.015 0.049 0.073 0.019 0.063 0.095
D 87.8 to 143.5 0.050 0.166 0.249 0.056 0.188 0.282
E 143.5 to 156.8 0.009 0.028 0.043 0.010 0.032 0.048
F 156.8 to 225.8 0.123 0.410 0.616 0.117 0.389 0.584
G 225.8 to 276.0 0.100 0.335 0.502 0.095 0.317 0.475
TOTAL 0.398 1.33 1.99 0.397 1.32 1.99

. Sand is calculated as 15% of total sediment yield (Randle and Pemberton, 1987),50%. and 75% to provide a range of possible input conditions.
See text for more discussion of these assumptions.

We supplemented this data by collecting
samples from 89 streamflow deposits in 21
tributaries in Glen and Grand Canyon and
analyzing them with standard techniques
(Kellerhals and Bray, 1971; Folk, 1974). Samples
were dried, then passed through brass sieves at 0.25
<p intervals using a rotational shaker. Particles
retained on each screen were weighed and the
percent of the subsample in each <p class
determined. Sand content in these samples ranged
from 30 - 100 percent (Table II). These data fit well
within the range suggested by other tributaries,
though the upper end is unlikely as high as 100
percent owing to a potential underrepresentation of
silt and clay in the streamflow deposits.

[n order to accommodate this wide range of
sand content, we calculated streamflow sand
delivery using three estimates. These include
Randle and Pemberton's (1987) value of 15 percent,
which we consider to be low, as well as 50 percent
and 75 percent of total streamflow sediment yield.
A sand content of 50 percent compares favorably
with average sand content weighted by discharge
for the Little Colorado and Paria Rivers, calculated
as 30 percent and 50 percent respectively (D.
Topping, U.S. Geological Survey, pers. commun.,
1999). The estimated sand delivery by streamflow,
using the data regression equation and Renard
(1972) equation, is shown by reach in table [2.
Assuming a 50 percent sand content, the sand

20 Sediment Delivery by Ungaged Trlbularles of the Colorado River In Grand Cenyon