Data Compilations - Plots, Commentary and Links

Estimating Salinity Constituent Concentrations

MWQI Conservative Constituents User Guide
MWQI Conservative Constituents User Guide Appendices
Delta Salinity Constituents Report

30-year Retrospective Overview of MWQI Program

30-year Retrospective Report
Vernalis Station
Vernalis
Hood Station
Hood
Banks Station
Banks
Hood Station
Gianelli
Jones PP
Jones

This site is supported by the State Water Contractors. It is based primarily on data from the California Department of Water Resources (DWR) Municipal Water Quality Investigations (MWQI) as part of the Real Time Data and Forecasting (RTDF) project. Its goal is to bring real time, near real time, and forecasted water quality data to source water managers, treatment plant operators, scientists, and other stakeholders. Data from numerous sources are assembled and presented with the goal of providing a concise, single source of relevant information. Data are presented in tables and graphs in combinations that are specific to particular concerns.

RTDF field data is the primary source of data and originates from 46 real-time field sensors at 5 MWQI stations measuring key water quality constituents, with organic carbon and bromide the primary focus. Of the 46 sensors, 31 are operated by MWQI and the other 15 by DWR's Division of Operations and Maintenance, DWR's Environmental Water Quality and Estuarine Studies Branch, the US Geological Survey, and the San Luis Delta Mendota Water Authority. Information provided by the the real-time stations is supplemented with other, selected water quality and hydrology data reported to CDEC by other agencies with links provided to specific websites that contain pertinent information.

Operations data, available on the daily dispatcher's report from DWR operations, provide daily pumping and generation flows and daily storage for selected projects. Electroconductivity (EC) forecasts at key delta export locations are provided by DWR's operations modeling group and include observed values for comparison; observed values are provided through CDEC. Daily EC, bromide and dissolved organic carbon (DOC) forecasts are also provided by DWR's operations modeling group for stations along the California Aqueduct and its principal branches.

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Summary Table (updated daily)

Mean daily values and seven day averages. Values less than the instrument reporting limit are annotated as (<RL). All Data are preliminary.

4/22/2025 4/28/2025 % Change 7-day Average
Sacramento River (Hood)
Mean Daily Flow, cfs 34,295 20,736 -40 ⇓ 26,447
Salinity (EC), µS/cm 115 138 +19 ⇑ 127
DOC, mg/L (Calculated) 1.96 2.07 +5 ⇑ 2.02
TOC, mg/L (Calculated) 2.00 2.12 +6 ⇑ 2.07
 
San Joaquin River (Vernalis)
Mean Daily Flow, cfs 2,246 2,506 +12 ⇑ 2,343
Salinity (EC), µS/cm 302 338 +12 ⇑ 294
DOC, mg/L 2.61 2.50 -4 ⇓ 2.48
TOC, mg/L 3.06 2.90 -5 ⇓ 2.91
Bromide, mg/L 0.21 0.17 -17 ⇓ 0.18
 
H.O. Banks Pumping Plant (SWP)
Mean Daily Pumping, cfs 623 408 -34 ⇓ 517
Salinity (EC), µS/cm 309 333 +8 ⇑ 319
DOC, mg/L 4.21 3.82 -9 ⇓ 4.02
TOC, mg/L 4.81 4.28 -11 ⇓ 4.51
Bromide, mg/L 0.18 m --- 0.18
Turbidity, NTU 5.47 9.76 +79 ⇑ 7.46
 
C.W. Jones Pumping Plant (DMC)
Mean Daily Pumping, cfs 911 920 +1 ⇑ 1,131
Old River Flow, cfs 1,219 1,409 +16 ⇑ 1,341
Salinity (EC), µS/cm 409 360 -12 ⇓ 365
DOC, mg/L 3.72 3.42 -8 ⇓ 3.75
TOC, mg/L 3.91 3.54 -9 ⇓ 3.92
Bromide, mg/L m m --- ---
Dissolved Oxygen, mg/L 8.25 7.61 -8 ⇓ 8.11
Turbidity, NTU 6.21 7.63 +23 ⇑ 7.38
Chloride, mg/L m m --- ---
Nitrate, mg/L m m --- ---
Sulfate, mg/L m m --- ---
pH 7.73 7.56 -2 ⇓ 7.72
Temp, C 20 18 -13 ⇓ 18
 
Gianelli Pumping Plant (SWP)
Mean Daily Pumping, cfs 4.03 0.00 -100 ⇓ 0.58
Mean Daily Generation, cfs 5,886 4,010 -32 ⇓ 5,056
Salinity (EC), µS/cm 417 417 <1 417
DOC, mg/L 3.43 3.47 +1 ⇑ 3.46
TOC, mg/L 3.36 3.41 +1 ⇑ 3.36
Bromide, mg/L 0.38 m --- 0.38
Dissolved Oxygen, mg/L 9.19 9.15 <1 9.10
Turbidity, NTU 1.28 1.37 +7 ⇑ 1.29
Nitrate, mg/L 2.61 m --- 2.61
Chloride, mg/L 67 m --- 67
Sulfate, mg/L 40 m --- 40
pH 7.73 7.74 <1 7.72
Temp, C 14 14 <1 14
 
Barker Slough Pumping Plant
Mean Daily Pumping, cfs 42 49 +18 ⇑ 48
Salinity (EC), µS/cm 390 328 -16 ⇓ 361
Turbidity, NTU 7.64 9.06 +19 ⇑ 8.72
 
Victoria Canal Near Byron
Salinity (EC), µS/cm 273 282 +3 ⇑ 279
 
California Aqueduct TDS (est. from EC)
Banks, mg/L m m --- ---
Check 41, mg/L m m --- ---
Check 66, mg/L 183 218 +19 ⇑ 209
 
Delta Total Outflow
Outflow, cfs 35,414 26,660 -25 ⇓ 29,701
 
Devils Canyon Afterbay
Salinity (EC), µS/cm 385 385 <1 384
Turbidity, NTU m m --- ---
 

Acknowledgements

Data for this report has been provided by: 

California Department of Water Resources
Bay-Delta Office

Division of Environmental Services
Office of Water Quality 

Division of Flood Management

California Data Exchange Center 

Division of Operations and Maintenance

Field Divisions
Water Management Branch
Water Quality Section

Contra Costa Water District 

United States Department of the Interior

Bureau of Reclamation
U.S. Geological Survey

National Oceanic and Atmospheric Administration

California Nevada River Forecast Center

University of Nebraska at Lincoln

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