Indicators

Nutrients

Total Nitrogen - Discrete

Scatter plot of monthly average total nitrogen over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only nitrogen values obtained from laboratory analyses (triangles) are included in the plot.
Scatter plot of monthly average total nitrogen over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only nitrogen values obtained from laboratory analyses (triangles) are included in the plot.
Seasonal Kendall-Tau Results for - Total Nitrogen
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab Significantly decreasing trend 306 13 2004 - 2025 0.658 -0.26718 0.9433 -0.01557 0.0001

Monthly average total nitrogen decreased by 0.02 mg/L per year.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Total Phosphorus - Discrete

Scatter plot of monthly average total phosphorus over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only phosphorus values obtained from laboratory analyses (triangles) are included in the plot.
Scatter plot of monthly average total phosphorus over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only phosphorus values obtained from laboratory analyses (triangles) are included in the plot.
Seasonal Kendall-Tau Results for - Total Phosphorus
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab Significantly decreasing trend 2075 17 2004 - 2025 0.077 -0.27394 0.1013 -0.00136 0

Monthly average total phosphorus decreased by less than 0.01 mg/L per year.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Water Quality

Dissolved Oxygen - Continuous

Scatter plot of monthly average dissolved oxygen over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average dissolved oxygen over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results - Dissolved Oxygen
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
gtmpcwq No significant trend 736088 26 2001 - 2026 5.5 0.05 5.26 0.01 0.1932

No detectable change in monthly average dissolved oxygen was observed at one location.

Map showing location of dissolved oxygen continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of dissolved oxygen continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Dissolved Oxygen - Discrete

Scatter plot of monthly average dissolved oxygen over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only dissolved oxygen values measured in the field (circles) are included in the plot.
Scatter plot of monthly average dissolved oxygen over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only dissolved oxygen values measured in the field (circles) are included in the plot.
Seasonal Kendall-Tau Results for - Dissolved Oxygen
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field Significantly increasing trend 1889 17 2004 - 2025 5.53 0.13974 4.92719 0.02393 0.0134

Monthly average dissolved oxygen increased by 0.02 mg/L per year.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Dissolved Oxygen Saturation - Continuous

Scatter plot of monthly average dissolved oxygen saturation over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average dissolved oxygen saturation over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results - Dissolved Oxygen Saturation
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
gtmpcwq No significant trend 737581 26 2001 - 2026 71.5 0.03 68.01 0.04 0.4939

No detectable change in monthly average dissolved oxygen saturation was observed at one location.

Map showing location of dissolved oxygen saturation continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of dissolved oxygen saturation continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Dissolved Oxygen Saturation - Discrete

Scatter plot of monthly average dissolved oxygen saturation over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only dissolved oxygen saturation values measured in the field (circles) are included in the plot.
Scatter plot of monthly average dissolved oxygen saturation over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only dissolved oxygen saturation values measured in the field (circles) are included in the plot.
Seasonal Kendall-Tau Results for - Dissolved Oxygen Saturation
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field No significant trend 201 11 2004 - 2023 55.5 0.08238 60.80703 0.14922 0.6126

Dissolved oxygen saturation showed no detectable trend between 2004 and 2023.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Salinity - Discrete

Scatter plot of monthly average salinity over time. If the time series included ten or more years of discrete observations, significant (blue) or non-significant (magenta) trend lines are also shown. Discrete salinity values derived from grab samples analyzed in the field (circles) or the laboratory (triangles) are both included in the plot.
Scatter plot of monthly average salinity over time. If the time series included ten or more years of discrete observations, significant (blue) or non-significant (magenta) trend lines are also shown. Discrete salinity values derived from grab samples analyzed in the field (circles) or the laboratory (triangles) are both included in the plot.
Seasonal Kendall-Tau Results for - Salinity
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
All No significant trend 3079 24 2002 - 2025 16.2 -0.03123 16.39596 -0.05765 0.494

Salinity showed no detectable trend between 2002 and 2025.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Salinity - Continuous

Scatter plot of monthly average salinity over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average salinity over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results - Salinity
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
gtmpcwq Significantly decreasing trend 745868 26 2001 - 2026 16.6 -0.12 16.31 -0.19 0.0027

At one program location, monthly average salinity decreased by 0.19 ppt per year.

Map showing location of salinity continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of salinity continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Water Temperature - Continuous

Scatter plot of monthly average water temperature over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average water temperature over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results - Water Temperature
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
gtmpcwq Significantly increasing trend 754434 26 2001 - 2026 24.3 0.15 23.64 0.04 0.0002

At one program location, monthly average water temperature increased by 0.04°C per year.

Map showing location of water temperature continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of water temperature continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Water Temperature - Discrete

Scatter plot of monthly average water temperature over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only water temperature measurements taken in the field (circles) are included in the plot.
Scatter plot of monthly average water temperature over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only water temperature measurements taken in the field (circles) are included in the plot.
Seasonal Kendall-Tau Results for - Water Temperature
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field Significantly increasing trend 2034 17 2004 - 2025 24.016 0.23139 22.44261 0.1088 0

Monthly average water temperature increased by 0.11°C per year.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

pH - Continuous

Scatter plot of monthly average pH over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average pH over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results - pH
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
gtmpcwq No significant trend 730315 26 2001 - 2026 7.4 -0.08 7.44 0 0.0568

No detectable change in monthly average pH was observed at one location.

Map showing location of ph continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of ph continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

pH - Discrete

Scatter plot of monthly average pH over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only pH values measured in the field (circles) are included in the plot.
Scatter plot of monthly average pH over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only pH values measured in the field (circles) are included in the plot.
Seasonal Kendall-Tau Results for - pH
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field Significantly increasing trend 1964 17 2004 - 2025 7.29 0.18423 6.87882 0.02006 0.0009

Monthly average pH increased by 0.02 pH units per year.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Specific Conductivity - Continuous

Seasonal Kendall-Tau Results - Specific Conductivity
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
gtmpcwq Significantly decreasing trend 746635 26 2001 - 2026 27.04 -0.13 27.25 -0.3 0.002
Map showing location of specific conductivity continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of specific conductivity continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Water Clarity

Turbidity - Continuous

Scatter plot of monthly average turbidity over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average turbidity over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results - Turbidity
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
gtmpcwq Significantly decreasing trend 721298 26 2001 - 2026 9 -0.17 9.8 -0.1 0

At one program location, monthly average turbidity decreased by 0.10 NTU per year.

Map showing location of turbidity continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of turbidity continuous water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Turbidity - Discrete

Scatter plot of monthly average turbidity over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only turbidity values measured in the laboratory (triangles) are included in the plot.
Scatter plot of monthly average turbidity over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only turbidity values measured in the laboratory (triangles) are included in the plot.
Seasonal Kendall-Tau Results for - Turbidity
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab Insufficient data to calculate trend 237 9 2004 - 2021 7 - - - -

There was insufficient data to fit a model for turbidity.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Total Suspended Solids - Discrete

Scatter plot of monthly average total suspended solids (TSS) over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only TSS values obtained from laboratory analyses (triangles) are included in the plot.
Scatter plot of monthly average total suspended solids (TSS) over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only TSS values obtained from laboratory analyses (triangles) are included in the plot.
Seasonal Kendall-Tau Results for - Total Suspended Solids
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab No significant trend 1936 16 2005 - 2025 14 0.00063 15.28497 0 1

Total suspended solids showed no detectable trend between 2005 and 2025.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Chlorophyll a, Uncorrected for Pheophytin - Discrete

Scatter plot of monthly average levels of chlorophyll a, uncorrected for pheophytin, over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed chlorophyll a (triangles) is included in the plot.
Scatter plot of monthly average levels of chlorophyll a, uncorrected for pheophytin, over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed chlorophyll a (triangles) is included in the plot.
Seasonal Kendall-Tau Results for - Chlorophyll a, Uncorrected for Pheophytin
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab No significant trend 1957 14 2012 - 2025 6.2 -0.05565 7.89913 -0.07205 0.3562

Chlorophyll a, uncorrected for pheophytin, showed no detectable trend between 2012 and 2025.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Chlorophyll a, Corrected for Pheophytin - Discrete

Scatter plot of monthly average levels of chlorophyll a, corrected for pheophytin, over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed chlorophyll a (triangles) is included in the plot.
Scatter plot of monthly average levels of chlorophyll a, corrected for pheophytin, over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed chlorophyll a (triangles) is included in the plot.
Seasonal Kendall-Tau Results for - Chlorophyll a, Corrected for Pheophytin
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab Significantly increasing trend 1984 17 2004 - 2025 4.7 0.19662 2.94274 0.14839 0.0006

Monthly average chlorophyll a, corrected for pheophytin, increased by 0.15 µg/L per year, indicating a decrease in water clarity.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Secchi Depth - Discrete

Scatter plot of monthly average Secchi depth over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Secchi depth is only measured in the field (circles).
Scatter plot of monthly average Secchi depth over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Secchi depth is only measured in the field (circles).
Seasonal Kendall-Tau Results for - Secchi Depth
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field Significantly increasing trend 359 17 2002 - 2022 -0.6 0.12513 -0.6937 0.00556 0.0435

Monthly average Secchi depth became shallower by 0.01 m per year, indicating a decrease in water clarity.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Colored Dissolved Organic Matter - Discrete

Scatter plot of monthly average colored dissolved organic matter (CDOM) over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed CDOM (triangles) is included in the plot.
Scatter plot of monthly average colored dissolved organic matter (CDOM) over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed CDOM (triangles) is included in the plot.
Seasonal Kendall-Tau Results for - Colored Dissolved Organic Matter
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab Insufficient data to calculate trend 57 5 2021 - 2025 76 - - - -

There was insufficient data to fit a model for colored dissolved organic matter.

Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Pellicer Creek Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.