WSP00521

• File Number: 8200.765
• Description: White River General
• State: CO
• Basin: Yampa/White
• Water Division: 6
• Date: 1/1/1990
• Author: USGS
• Title: Water Quality and Sediment-Transport Characteristics in Kenney Reservoir - White River Basin - Northwestern Colorado
• Water Supply Pro - Doc Type: Report/Study

June 19, 1987, a maximum pH of 9.2 was measured at depths of 1 ft or less
(fig. 8). The large pH values (greater than 9.0) were associated with dense
subsurface growths of phytoplankton that seemed to be confined to depths of
less than 1 ft. Values of pH decreased to less than 9.0 below (fig. 8) and
laterally (fig. 6, tables 11 and 12) from observed patches of phytoplankton.
Except for the biologically active zones near the surface and near the bottom
of Kenney Reservoir, ranges of pH values were similar to the range of pH
values in the White River (site 3).

Dissolved Oxygen and Biochemical Oxygen Demand

Oxygen dissolves in water to a concentration controlled by the atmos-
pheric partial pressure of the gas and the temperature and salinity of the
water. Concentrations of dissolved oxygen at 100-percent saturation will
increase as water temperature decreases and (or) atmospheric pressure
increases.

Except for photosynthesis, almost all oxygen transfer to the water occurs
at the air-water interface. Because oxygen diffuses very slowly in calm water
(Hutchinson, 1957), winds, water turbulence, and currents are major factors in
the aeration of a water body.

. 0 0 0
I
I
tu I
I
I
W "
... 5 t 5 5
~ I
w' I
/
U /
~ 1
a: 10 ,/ ~o 10
:> ;t
(/) ,
/;
a: I'
w 1\
f-'
<. / ,
~ 1 ,
'5 I , 15 '5
,
~ I ,
I ,
w
CD - Temperature
J: 20 - -- Dissolved oxygen 20 20
Ii: 7 8 8 10 400 450 500 560 600
w ..... Dissolved oxygen at
0 100 percent saturation pH (UNITS) SPECIFIC CONDUCTANCE,
IN MICROSIEMENS PER
25 CENTIMETER AT 25
0 5 10 '5 20 25 DEGREES CELSIUS
TEMPERATURE, IN DEGREES CELSIUS
DISSOLVED OXYGEN, IN
MILLIGRAMS PER LITER

Figure 8.--Water temperature, specific conductance, pH, and dissolved
oxygen near the center of Kenney Reservoir, between sites 1 and 2,
during a phytoplankton bloom, Jun~ 19, 1987.

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