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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Sediment Transport and Water-Quality Characteristics
and Loads, White River, Northwestern Colorado,
Water Years 1975-88

ByR.L. Tobin

Abstract

Streamflow, sediment, and water-quality data for
water years 1975-88 were compiled, analyzed, and
compared for six streamflow-gaging stations and a sec-
ondary data site on the White River in northwestern
Colorado. Data from two tributary streamflow-gaging
stations and a discontinued streamflow-gaging station
on the main stem were used to generate estimates of
annual data for years of no data at two downstream
sites. Annual loads of suspended sediment and dis-
solved solids were determined from regression esti-
mates of daily loads. Onsite measurements of water
quality were correlated with stream discharge, and
concentrations of major ions, hardness, and dissolved
solids were correlated with values of specific conduct-
ance. Concentration ranges of nutrients and trace con-
stituents were determined.
Most stream discharge in the White River
occurred during May and June from melted snowpack
in the eastern part of the basin. The combined annual
streamflow of the North Fork and South Fork
accounted for about 78 percent of the total stream dis-
charge in the White River. Annual stream discharge in
the main stem ranged from about 200,000 acre-feet at
most sites to about 1 million acre-feet at the most
downstream site. Average annual stream discharge at
the most downstream site was about 577 ,000 acre-feet.
Bedload in 24 of 25 measurements at 5 sites was
3.3 percent or less of the total sediment load; bedload
was not considered substantial in the estimates of
annual sediment loads. Annual suspended-sediment
loads ranged from about 2,100 tons in the North Fork
and South Fork to about 2 million tons at the most
downstream site. Average annual suspended-sediment
loads ranged from about 11,000 tons in the North Fork
and South Fork to about 705,000 tons at the most
downstream site. Vegetation cover and resistant strata
probably decreased sediment transport from the basin
upstream from the site downstream from Meeker.
The average size composition of suspended sed-
iment in 27 samples collected for full-size analysis was
30 percent sand, 45 percent silt, and 25 percent clay.
Sand percentage ranged from 2 to 64 percent in
174 samples collected for concentrations of suspended

sediment. Annual capacity losses from sediment reten-
tion in a hypothetical 50,000 acre-foot reservoir con-
structed on the White River could range from less than
0.01 percent in the North Fork and South Fork to about
2.5 percent near the downstream sites. Estimates of
volume displacement and percent capacity loss for a
range of reservoir sizes were determined.
Maximum water temperatures in summer gener-
ally ranged from less than 20 degrees Celsius upstream
from Meeker to 20 to 25 degrees Celsius downstream
from Meeker. Specific conductance generally ranged
from 200 to 400 microsiemens per centimeter in the
North Fork and South Fork to 300 to 1,000 microsie-
mens per centimeter at the downstream sites. Values of
specific conductance decreased as stream discharge
increased.
Generally, values of pH at all sites ranged from
7.6 to 8.8, but the range generally decreased from 8.0
to 8.5 in high streamflow. The chemical buffering
capacity in streamflow to resist possible changes in pH
from biological activities was greatest at the down-
stream sites. Concentrations of dissolved oxygen were
greater than 6.0 milligrams per liter at all sites. Biolog-
ical activities during daytime probably caused values
of dissolved oxygen to exceed l20-percent saturation.
Concentrations of dissolved solids generally
ranged from about 100 milligrams per liter in the North
Fork and South Fork to 630 milligrams per liter at the
most downstream site. In low streamflow, composition
of dissolved solids was mostly calcium, bicarbonate,
and (or) sulfate upstream from the site downstream
from Meeker, and mostly calcium, sodium, sulfate, and
bicarbonate at the two most downstream sites. Cal-
cium and bicarbonate were the principal constituents at
all sites in the high streamflow during snowmelt runoff.
Annual loads of dissolved solids ranged
from about 21,100 tons in the South Fork to about
480,000 tons at the most downstream site, Total solids
transported in the White River were mostly as dis-
solved solids upstream from the site downstream from
Meeker and mostly as suspended sediment at the two
downstream sites.
Concentrations of ammonia as nitrogen in 46 of
51 samples at all sites were less than 0.05 milligram per

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