Temperature Data from Automated Recorders

Temperature Data from Automated Recorders

SYRCL obtained 19 automated temperature recorders (loggers) in 2007 with financial assistance from the California Hydropower Reform Coalition and private donors.  These loggers have been deployed at the locations noted in the table below, and programmed to record data at intervals ranging from 15 minutes to 4 hours (most typically 1 hour).  They are placed in fully mixed running water with a start date in late spring or early summer, and retrieved in the fall prior to winter storms.

Temperature data from loggers is presented primarily in two types of charts.  Daily charts plot the daily minimum, maximum and average temperature. The daily span between maximum and minimum temperatures represents diel variation which is greater in water bodies with less insulation from riparian canopy. Weekly temperature charts plot the 7-day floating average temperature (average of the daily averages for three days prior and later).  This type of chart provides a smoother line and a better representation of the temperature level to which aquatic organisms are chronically exposed. 

The reference values shown on the temperature charts come from the Upper Yuba River Watershed Temperature Criteria for Chinook Salmon and Steelhead (Stillwater Sciences, 2006).  A reference value of 25 degrees C is shown on daily charts as a threshold for lethal stress because studies cited in this report show significant mortality for juvenile salmonids above this temperature.  As stated in the document, however, “upper lethal temperature in streams can be influenced by local genetic and physiological adaptations, food availability, acclimation temperatures, behavioral adaptations and access to cool water refugia”.

The most common metric used in evaluating the suitability of stream temperature to fish is maximum weekly average temperature or MWAT (em-waht). The Upper Yuba Report lists a variety of thresholds for evaluating MWATs based on species and life stage, as well as optimal and suboptimal ranges.  The value of 19 deg. C (66 F) is the threshold above which chronic to acute stress is expected for adult spring-run Chinook salmon.  The value of 20 deg. C (68F) is the threshold above which the same is expected for juvenile steelhead or rainbow trout.

The table below indicates where (and for what years) complete records of summer water temperatures were obtained by noting the MWAT in deg. C.  Where “no data” is entered, loggers were malfunctioned or were stolen.  Partial records typically resulted from exposure to air following flow recession.
 

Station ID

Sub basin

Site Location

2007

2008

2009

2010

2011

101

SY

South Yuba above Scotchman Creek

23.7

23.3

24

 

22

102

SY

South Yuba below Scotchman Creek

23

23

partial record

23.7

21.8

103

SY

South Yuba upstream from Edwards Crossing

25

 

 

 

 

104

SY

South Yuba below Spring Creek

25

 

 

 

 

105

SY

South Yuba at Bridgeport

partial record

25.5

 

24.3

26.3

106

MY

Middle Yuba above Our House Dam

23.8

 

 

 

23.6

107

MY

Middle Yuba below Highway 49 (public)

partial record

24.3

no data

26.8

 

108

SY

Fordyce Creek

16

 

 

 

 

109

SY

South Yuba at Langs Crossing

partial record

13.3

 

15.8

 

110

SY

Jordan Creek

18.5

 

 

19.6

 

112

SY

Bowman-Spaulding Canal below Fuller Lake

17.1

 

 

 

 

113

SY

Bowman-Spaulding Canal near Bowman

16.7

 

 

 

 

114

SY

South Yuba Canal near Bowman Rd

17.3

 

 

 

 

115

SY

South Yuba above Spaulding

20.7

 

 

 

 

117

SY

Scotchman Creek at Rorie's property

 

16.5

16.4

 

17.1

118

MY

Oregon Creek near mouth (public)

 

20.8

20.7

22.8

 

119

MY

Oregon Creek near Camptonville

 

20.9

21

24.1

 

120

LY

Dry Creek

 

23.5

no data

28.7

25.3

121

NY

North Yuba below Highway 49

 

21.7

 

 

 

124

SY

South Yuba Below Poorman Creek

 

20.2

 

 

 

125

NY

Main Yuba below Colgate

 

 

9.7

 2010 data suspect

 

126

NY

North Yuba at Union Flat

 

 

partial record

 

 

127

NY

Lavezzola Creek

 

 

14.3

 

 

128

NY

North Yuba below Fiddle Creek

 

 

21.6

 

 

129

SY

South Yuba at Indian Springs

 

 

no data

 

20.9

131

NY

Canyon Creek

 

 

21.9

 

20.6

132

NY

Pauley Creek

 

 

17.3

 

 

133.2106

LY

Hammon Backwater - second lowest

 

 

15.4

 

 

133.3

LY

Hammon Backwater - middle

 

 

14.9

 

 

134

LY

Hammon Backwater - top

 

 

16.9

 

 

135

LY

Lower Yuba main channel

 

 

14.4

 

 

140

SYT

Lower Rush Creek

 

 

 

 

22.1

141

SYT

Kentucky Ravine

 

 

 

28.2

 

 

LY

Dry Creek Below Collins Reservoir

 

 

 

 

13.5