WSP07706

• File Number: 8200.765
• Description: White River General
• State: CO
• Basin: Yampa/White
• Water Division: 6
• Date: 1/1/1993
• Author: USGS
• Title: Sediment Transport and Water-Quality Characteristics and Loads - White River - Northwestern Colorado - Water Years 1975 through 1988
• Water Supply Pro - Doc Type: Report/Study

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and bedload was not included in estimates of annual
sediment loads in the White River.
Annual suspended-sediment loads in the White
River ranged from about 2,100 tons at sites 1 and 2 to
about 2 million tons at site 6. Average annual
suspended-sediment loads were least in the North Fork
and South Fork at sites 1 and 2 (11,500 and
11,100 tons) and greatest at site 6 (about 705,000 tons).
Annual suspended-sediment loads greatly increased
downstream from site 4. The increases in sediment
loads were from the accumulative inputs of sediment
eroded from poorly consolidated strata in the semiarid
tributary basins between sites 4 and 6. Extensive veg-
etation cover or resistant strata or both in the tributary
basins upstream from site 4 substantially decreased
sediment erosion and transport.
The average size composition of suspended sed-
iment in 27 samples collected for size analysis at sites
3-6 was 30 percent sand, 45 percent silt, and 25 percent
clay. Sand percentages in 174 samples collected for
sediment concentrations, however, ranged from 2 to
64 percent. Data correlations of size composition with
stream discharge and sediment concentration were
poor.
Sediment retention in proposed reservoirs larger
than 13,800 acre-ft on the White River could exceed
98 percent. Annual capacity loss in a hypothetical
50,000 acre-ft reservoir could range from less than
0.01 percent near sites 1 and 2 to about 2.5 percent near
site 6. Annual capacity losses for a range of hypothet-
ical reservoir sizes constructed on the White River at or
near sites 1-6 were estimated.
Water temperature, specific conductance, pH,
and dissolved oxygen were measured periodically at
sites 1-6. Maximum water temperatures in summer
generally ranged from less than 2O"C at sites 1-3 to 20
to 25"C at sites 4-6. Daily changes in temperature from
3 to 80C at site 4 were typical during summer.
Specific conductance in the White River
decreased as stream discharge from snowmelt
increased. Values of specific conductance and ranges
of specific conductance were least, generally from 200
to 400 I1S/cm at sites 1 and 2, and increased gradually
to 300 to 1,000 I1S/cm downstream to site 6. Large
values of specific conductance (750 to 1,100 I1S/cm)
were measured at site 4 in low streamflow prior to
water year 1983. After recompletion in 1980-81 of
improperly completed exploratory wells 3 mi east of
Meeker, specific-conductance values at site 4 were less
than 750 I1S/cm.
Although extreme values of pH in the White
River ranged from 7.4 (site 4) to 9.1 (site 3), most val-
ues of pH ranged from 7 .6 to 8.8. The range in pH gen-
erally decreased to values that ranged from 8.0 to 8.5 in

high streamflow. Correlation of pH with dissolved
oxygen indicates that pH exceeded 8.5 at sites 1-4 only
when the percent saturation of dissolved oxygen
equaled or exceeded 100 percent. The chemical buff-
ering capacity in the river to resist biologically induced
changes in pH in low streamflow probably was greatest
in the White River downstream from site 4.
All concentrations of dissolved oxygen mea-
sured at sites 1-6 were greater than 6.0 mg/L; a maxi-
mum concentration of 14.2 mg/L was measured at site
4 when the water temperature was O"C. Photosynthetic
activity of algae and aquatic plants produced concen-
trations of dissolved oxygen that exceeded 120 percent
in the low streamflows at all sites. Most concentrations
of dissolved oxygen in the White River were greater
than 90-percent saturation. Thus, net daytime biologi-
calor chemical oxygen-consumption activities or both
in the White River probably were smaIl.
Concentrations of dissolved solids ranged from
about 100 to 250 mg/L at sites 1 and 2 to about 230 to
630 mg/L downstream at site 6. Concentrations of
dissolved solids (and major ions) were greatest in low
streamflow and least in high streamflow. In low
streamflow, composition of dissolved solids was
mostly calcium, bicarbonate, and (or) sulfate upstream
from site 4 and mostly calcium, sodium, sulfate, and
bicarbonate downstream from site 4. In snowmelt run-
off, when streamflow in the White River was greater
than 1,000 ft3/s, calcium and bicarbonate generally
were the principal constituents at all sites. Concentra-
tions of the major ions, hardness, and dissolved solids
were regressed on values of specific conductance.
Annual loads of dissolved solids in the White
River were computed from least-squares regressions
that related instantaneous dissolved-solids loads to
daily stream discharge for sites 1-6. Annual dissolved-
solids loads ranged from 21,100 tons at site 2 to an
estimated 480,000 tons at site 6. Average annual dis-
solved-solids loads were least at site 2 (38,700 tons)
and greatest at site 6 (about 348,000 tons). Data com-
parisons indicated that total solids transported in the
White River primarily were dissolved solids upstream
from site 4 and suspended sediment downstream from
site 4. Annual total solids in the White River ranged
from about 23,200 tons at site 2 to about 2.4 million
tons at site 6.
A total of 51 water samples for analyses of dis-
solved nutrients were collected periodically at sites 1-6
during water years 1987-88. Although concentrations
of ammonia as nitrogen ranged from less than
0.01 to 0.11 mg/L, ammonia concentrations were equal
to or less than 0.05 mglL in 46 of the 51 samples.
Concentrations of nitrite plus nitrate as nitrogen ranged
from less than 0.1 mg/L at all sites to 0.53 mg/L at

SUMMARY 67