Water Monitoring in the Pamunkey and Mattaponi Rivers

Dissolved oxygen and temperature levels in both the Pamunkey and Mattaponi Rivers are monitored daily (dependent on weather and river conditions) with HOBO U26-001 Data Loggers. Currently, loggers collect data at three positions (upper, middle, and lower) in the Pamunkey River and three positions in the Mattaponi River (upper, middle, and lower). The data are downloaded and posted by month as it becomes available.

The amount of gaseous oxygen dissolved in the water is a critical factor for assessing water quality. Low, or very high, levels, of dissolved oxygen negatively impact fish and other aquatic organisms. Water temperature affects the amount of dissolved oxygen in the water, as well as other biological aspects (i.e., metabolic rates of aquatic organisms) and chemical aspects (i.e., photosynthesis of aquatic plants). Dissolved oxygen and water temperature are primary stressors for the Atlantic Sturgeon.

Dissolved Oxygen and Temperature Readings in the Pamunkey and Mattaponi Rivers

Dissolved oxygen is the amount of gaseous oxygen dissolved in water and other liquids. It is a critical factor in accessing water quality since it impacts fish and other aquatic organisms. If the level of dissolved oxygen is too high or too low it can stress aquatic life.

Below is the data obtained from the loggers that have been placed in the Pamunkey and Mattaponi Rivers to monitor the dissolved oxygen and temperature.

  • Data that coincided with deploying, checking, and maintaining the logger has been removed.
  • The Upper Pamunkey River logger was not deployed until October 2018 due to flooding.
  • The Lower Mattaponi River logger required replacement and was positioned in a more secure location as of July 2019.

Celcius to Farenheit conversion: (°C x 1.8) + 32 = °F

2020 Current Month Water Monitoring Data

Pamunkey River

Upper Pamunkey River

February 2020 monitoring data (348 dissolved oxygen and temperature readings) logged dissolved oxygen levels ranging from 0.03 mg/L to 8.83 mg/L with an average of .46 mg/L. Water temperature ranged from 5.66 °C (42.18°F) to 9.42°C (48.96 °F) with an average of 7.96 °C (46.33 °F).

February 2020 Dissolved Oxygen Temperature
Recorded Samples 348 348
Maximum 8.83 Mg/L 9.42 °C
Minimum 0.03 mg/L 5.66 °C
Average 0.46 mg/L 7.96 °C

Middle Pamunkey River

February 2020 monitoring data (348 dissolved oxygen and temperature readings) logged dissolved oxygen levels ranging from 6.83 mg/L to 11.91 mg/L with an average of 10.7 mg/L. Water temperature ranged from 5.46°C (41.83°F) to 9.86°C (49.75°F) with an average of 7.82 °C (46.08°F).

February 2020 Dissolved Oxygen Temperature
Recorded Samples 348 348
Maximum 11.91 mg/L 9.86 °C
Minimum 6.83 mg/L 5.46 °C
Average 10.7 mg/L 7.82 °C

Lower Pamunkey River

February 2020 monitoring data (0 dissolved oxygen and 358 temperature readings) logged no dissolved oxygen levels. Water temperature ranged from -1.64°C (34.95°F) to 13.26°C (55.87°F) with an average of 8.33°C (46.99°F).

* U26 Logger was not recording data, temperature data collected from separate temperature logger at the same station.
February 2020 Dissolved Oxygen Temperature
Recorded Samples *0 358
Maximum * 13.26 °C
Minimum * -1.64 °C
Average * 8.33 °C

Mattaponi River

Upper Mattaponi

February 2020 monitoring data (348 dissolved oxygen and temperature readings) logged dissolved oxygen levels ranging from -0.02 mg/L to 3.78 mg/L with an average of .38 mg/L. Water temperature ranged from 5.0°C (41.0°F) to 9.38°C (48.88°F) with an average of 7.37°C (42.27°F).

February 2020 Dissolved Oxygen Temperature
Recorded Samples 348 348
Maximum 3.78 mg/L 9.38 °C
Minimum -0.02 mg/L 5.0 °C
Average 0.38 mg/L
7.37 °C

Middle Mattaponi

February 2020 monitoring data (348 dissolved oxygen and temperature readings) logged dissolved oxygen levels ranging from 0.09 mg/L to 10.15 mg/L with an average of 4.8 mg/L. Water temperature ranged from 4.06°C (39.31°F) to 10.42°C (50.76°F) with an average of 7.68°C (45.82°F).

February 2020 Dissolved Oxygen Temperature
Recorded Samples 348 348
Maximum 10.15 mg/L 10.42 °C
Minimum 0.09 mg/L 4.06 °C
Average 4.8 mg/L 7.68 °C

Lower Mattaponi

February 2020 monitoring data (348 dissolved oxygen and temperature readings) logged dissolved oxygen levels ranging from 10.01 mg/L to 11.60 mg/L with an average of 10.81 mg/L. Water temperature ranged from 5.98°C (42.76°F) to 9.36°C (48.85°F) with an average of 7.96°C (46.33°F).

February 2020 Dissolved Oxygen Temperature
Recorded Samples 348 348
Maximum 11.6 mg/L 9.36 °C
Minimum 10.01 mg/L 5.98 °C
Average 10.81 mg/L 7.96 °C