Figure 1. O. mykiss captured at the Calaveras River rotary screw trap.

The Calaveras River rotary screw trap at Shelton Road (RM 28) was operated twelve days between November 22 and December 12. A total of 165 O. mykiss were captured during the reporting period, with daily catches ranging between 2 and 93 individuals (Figure 1). Of the O. mykiss captured, 122 were measured, and all were Age 1+ (100-299 mm) rated as parr (n=7), silvery parr (n=67), and smolt (n=47). Average forklengths and weights of O. mykiss are provided in Table 1.

No Chinook salmon were captured during this reporting period.

Instantaneous temperature recorded at the trap ranged from 43.8�F to 54.6�F, and turbidity ranged from 0.48 NTU to 2.23 NTU. Daily average flow fluctuated between 21 cfs and 50 cfs at New Hogan Dam (NHG), 0 cfs to 38 cfs at Bellota (MRS), and 1 cfs to 30 cfs at Cosgrove Creek (COS; Figure 2).

Figure 2. Daily O. mykiss catch at Shelton Road, and Calaveras River flow recorded by New Hogan Dam (NHG) and Cosgrove Creek (COS) combined, and flow recorded at Bellota (MRS), between November 1 and December 12, 2010.

The Tuolumne River rotary screw trap at Waterford (RM 30) was installed December 1 and monitoring began on December 3 to sample during increased flows due to flood control. The trap sampled continuously between December 3 and December 12.

Figure 3. Chinook salmon fry captured at Tuolumne River rotary screw trap in Waterford.

A total of 17 juvenile Chinook salmon fry were captured during the reporting period. Daily catch ranged between zero and five Chinook (Figure 3). Average forklengths and weights of all the Chinook salmon are provided in Table 2. Most of the fry were buttoned up, and few sac-fry have been observed.

No O. mykiss were captured during this reporting period.

Instantaneous temperature taken at the trap ranged from 51.9�F to 54.3�F, and turbidity ranged from 1.11 NTU to 3.41 NTU. Daily average flow at La Grange (LGN) ranged between 1,900 cfs and 3,890 cfs (Figure 4).

Table 2. Biosampling data for Chinook salmon captured and measured at Waterford between December 3 and December 12, 2010. Parentheses indicate range.

Figure 4. Daily Chinook salmon catch at Waterford and Tuolumne River flow recorded by La Grange (LGN) and Modesto (MOD), 2009.

Between November 22 and December 12 a total of 117 fall-run Chinook salmon were detected by the Vaki Riverwatcher as they passed upstream of the Stanislaus River weir, increasing the season total to 1,346 (Figures 5). Daily passage during this sampling period ranged from 0 to 17 Chinook (Figure 6). The number of Chinook passages observed so far this year represents a slight increase over the total passages observed last year (Table 3).

Instantaneous water temperature measured at the weir ranged between 45.8˚F and 55.2˚F, and daily average water temperature at Ripon (RPN; RM 15) ranged between 46.9˚F and 56.8˚F (Figure 7). Instantaneous turbidity ranged between 0.63 NTU and 2.87 NTU (Figure 8). Instantaneous dissolved oxygen at the weir ranged between 9.25 mg/L and 12.17 mg/L, and daily average dissolved oxygen at Ripon (RPN; RM 15) ranged from 8.93 mg/L to 11.53 mg/L (Figure 9).

Daily average flows in the Stanislaus River at Goodwin Dam (GDW; RM 58) remained stable between 201 cfs and 208 cfs. Flows at Ripon (RIP; RM 15) fluctuated between 237 cfs and 283 cfs. Note: flows downstream of Goodwin Dam may differ from dam releases due to irrigation, precipitation and other factors.

Figure 5. Cumulative passage of fall-run Chinook salmon recorded at the Stanislaus River weir from 2003-2010.

Figure 10. Tuolumne River weir removal.

The Tuolumne River weir was removed on November 30 in anticipation of increased flows due to flood control releases that were expected to exceed the maximum operational flow for the weir (>1,500 cfs)(Figure 10).

Between November 22 and November 30 a total of 82 Chinook salmon were detected by the Vaki Riverwatcher as they passed upstream of the Tuolumne River weir, increasing the season total to 766 (Table 4). Daily passage ranged from 1 to 28 Chinook (Figure 12). The number of Chinook passages observed so far this year has exceeded the total passage count observed last year (Figure 11).

Instantaneous water temperature measured at the weir ranged between 48.3˚F and 54.3˚F. Daily average water temperature at Modesto (MOD; RM 17) was not available during the reporting period (Figure 13). Instantaneous turbidity ranged between 0.76 NTU and 2.62 NTU (Figure 14), and instantaneous dissolved oxygen ranged between 7.79 mg/L and 10.07 mg/L (Figure 15).

Daily average flows in the Tuolumne River increased from 360 cfs to 3,890 cfs at La Grange (LGN; RM 50) and from 437 cfs to 4,510 cfs at Modesto (MOD; RM 17). Note: flows downstream of La Grange may be higher than dam releases due to accretion and Dry Creek inflow.

Table 4. Annual fall-run Chinook passage at the Tuolumne River Weir, 2009 and 2010.

During the reporting period, flows increased in the San Joaquin River at Vernalis ranging from 1,761 cfs to 5,288 cfs (Figure 19). Water temperatures in the San Joaquin River fluctuated between 47.1�F and 54.7�F at Vernalis, between 47.5�F and 55.4�F at Mossdale, and between 51.0�F and 57.5�F at Rough 'n Ready Island (Figure 20). Average daily dissolved oxygen (DO) in the San Joaquin River fluctuated from 8.0 mg/L to 9.1 mg/L in the deep water ship channel (measured at Rough 'n Ready Island), and between 8.9 mg/L and 10.9 mg/L at Mossdale (Figure 21).

Mean daily pumping at the C.W. Jones Pumping Plant (federal pumps previously known as Tracy Pumping Plant) remained relatively stable during the reporting period and fluctuated between 4,062 cfs and 4,139 cfs (Figure 22). Mean daily pumping at the Harvey O. Banks Pumping Plant (state pumps) ranged between 4,489 cfs and 6,369 cfs. Combined total exports (state and federal pumps) during this period ranged from 8,551 cfs to 10,508 cfs.