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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streamflow periods and generally ranged from 20 to
250C at sites 4-6. Maximum temperatures mostly were
less than 20"C at sites 1-3. Minimum temperatures of
OOC were measured at all sites during winter.
In spring, when stream discharge from snowmelt
in the White River generally exceeded 1,000 to
2,000 ft3/s, stream temperature ranged from 5 to 180C
at sites 3-6. Analysis of available daily temperature
records at site 4 (water years 1978-83) indicates that
daily changes in temperature of 3 to 80C were typical
during summer.

Specific Conductance

Periodic measurements of specific conductance
and the relation of specific conductance to stream
discharge at sites 1-6 are shown in figure 14. The
mathematical expressions for estimating specific
conductance from stream discharge (fig. 14) are anti-
logs of the regressions that related log-transformed
values of specific conductance with log-transformed
values of stream discharge. The expressions include a
bias correction factor (Cb) derived from methods used
in equations 3 and 4. The large scatter of specific-
conductance values for sites 5 and 6 (fig. 14) probably
was caused by the seasonal or intermittent inflow of
water that had large values of specific conductance.
The water entered the White River as irrigation return
flow or as early spring runoff from the low-elevation
basins, or both.
Because specific-conductance values are small in
snowmelt, specific conductance decreased at all sites as
streamflow increased during the spring runoff. Values
and ranges of specific conductance were least (gener-
ally from 200 to 400 I1S/cm) at sites I and 2 and
increased (generally from 300 to 1,000 I1S/cm) down-
stream to site 6. Large values of specific conductance
(from 750 to I, I 00 I1S/cm) were measured at site 4 dur-
ing periods of low streamflow prior to water year 1983
(fig. 15). The large values were attributed to the inflow
of ground water that had large values of specific con-
ductance that discharged to the White River from seeps
and springs. The seeps and springs most likely were
associated with improperly completed gas and oil
exploratory wells (CH2M Hill Central, 1982). The
wells were drilled into a geologic and topographic
structure known as the Meeker dome, 3 mi east of
Meeker (fig. 2). The wells were recompleted and
plugged during 1980-81 (water years 1980-82) through
efforts sponsored by the U.S. Bureau of Reclamation.
Measurements of specific conductance at site 4 were
less than 750 I1S/cm during water years 1983-88
(fig. 15).

pH

Values of pH at sites 1-6 are plotted against
stream discharge in figure 16. Although pH values in
the White River ranged from 7.4 (site 4) to 9.1 (site 3),
most values of pH ranged from 7.6 to 8.8. In the high
streamflow of spring runoff, pH values at sites 1 and 2
generally ranged from 8.0 to 8.3, and pH in the main
stem of the White River (sites 3-6) mostly ranged from
8.0 to 8.5. Except for the single unexplained pH value
of9.1 at site 3 (fig. 16), the pH range generally was
greatest at all sites during low streamflow.
Correlation of pH with dissolved oxygen for sites
1-6 indicates that pH exceeded 8.5 at sites 1-4 only
when the percent saturation of dissolved oxygen
equaled or exceeded 100 percent. A similar correlation
was not evident at sites 5 and 6. Also, the ranges of pH
values at sites 5 and 6 generally were smaller than the
ranges of pH values at sites 1-4. During low stream-
flow, when values of specific conductance were greater
at sites downstream than sites upstream, the chemical
buffering capacity in the river to resist biologically
induced changes in pH generally was greater in the
White River downstream from site 4 than in the upper
White River at sites 1-4.

Dissolved Oxygen

The saturated concentration of dissolved oxygen
in streams is directly related to the partial pressure of
atmospheric oxygen and inversely related to water tem-
perature. Concentrations that deviate from the 100-
percent saturation values in natural water primarily are
caused by metabolic processes. Oxygen is produced
from the photosynthesis of algae and plants, and oxy-
gen is consumed by respiration and during the decom-
position of organic matter. Correlation of dissolved
oxygen and temperature, and the 90-, 100-, and 120-
percent saturation curves for sites 1-6 are shown in fig-
ure 17. Concentrations greater than the l00-percent
saturation curve indicate a super-saturated condition;
concentrations less than the curve indicate an unsatur-
ated condition. A comparison of data at sites 1-6
(fig. 17) indicates the following:

I. All concentrations of dissolved oxygen mea-
sured at sites 1-6 were greater than 6.0 mgIL.
Concentrations were greatest during winter; a
maximum concentration of 14.2 mgIL was
measured at site 4 when the water temperature
was O"C.

2. Photosynthetic activities, as measured by the
relative frequency and extent of dissolved-
oxygen concentrations greater than the 100-

WATER-QUALITY CHARACTERISTICS AND LOADS 31