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 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

2019 Cumulative and Current Month Water Monitoring Data

Pamunkey River

Upper Pamunkey River

June 2019 monitoring data (360 dissolved oxygen and temperature readings) logged dissolved oxygen levels ranging from 6.09 mg/L to 7.67 mg/L with an average of 6.88 mg/L. Water temperature ranged from 20.18 °C (68.32 °F) to 29.02 °C (84.24 °F) with an average of 24.30 °C (75.74 °F).

June 2019 Dissolved Oxygen Temperature
Recorded Samples 360 360
Maximum 7.67 mg/L 29.02 °C
Minimum 6.09 mg/L 20.18 °C
Average 6.88 mg/L 24.30 °C

Middle Pamunkey River

June 2019 monitoring data (360 dissolved oxygen and temperature readings) logged dissolved oxygen levels ranging from 1.74 mg/L to8.19 mg/L with an average of 6.03 mg/L. Water temperature ranged from 20.4 °C (68.72 °F) to 29.02 °C (84.24 °F) with an average of 24.61 °C (76.30 °F).

June 2019 Dissolved Oxygen Temperature
Recorded Samples 360 360
Maximum 8.19 mg/L 29.02 °C
Minimum 1.74 mg/L 20.4 °C
Average 6.03 mg/L 24.61 °C

Lower Pamunkey River

June 2019 monitoring data (360 dissolved oxygen and temperature readings) logged dissolved oxygen levels ranging from 0.23 mg/L to 7.18 mg/L with an average of 4.80 mg/L. Water temperature ranged from 22.78 °C (73.0 °F) to 30.54 °C (86.97 °F) with an average of 26.52 °C (79.74 °F).

June 2019 Dissolved Oxygen Temperature
Recorded Samples 360 360
Maximum 7.18 mg/L 30.54 °C
Minimum 0.23 mg/L 22.78 °C
Average 4.80 mg/L 26.52 °C

Mattaponi River

Upper Mattaponi

June 2019 monitoring data (360 dissolved oxygen and temperature readings) logged dissolved oxygen levels ranging from -0.03 mg/L to 6.94 mg/L with an average of 0.16 mg/L. Water temperature ranged from 20.5 °C (68.9 °F) to 27.84 °C (82.11 °F) with an average of 23.56 °C (74.41 °F).

*Note: Monitor for dissolved oxygen was offline June 1 – 26, 2019.

June 2019 Dissolved Oxygen Temperature
Recorded Samples 360 360
Maximum 6.94 mg/L 27.84 °C
Minimum -0.03 mg/L 20.5 °C
Average 0.16 mg/L 23.56 °C

Middle Mattaponi

June 2019 monitoring data (360 dissolved oxygen and temperature readings) logged dissolved oxygen levels ranging from 3.94 mg/L to 7.64 mg/L with an average of 5.78 mg/L. Water temperature ranged from 20.96 °C (69.73 °F)  to 31.4 °C (88.52 °F)  with an average of 25.94 °C (78.96 °F).

June 2019 Dissolved Oxygen Temperature
Recorded Samples 360 360
Maximum 7.64 mg/L 31.4 °C
Minimum 3.94 mg/L 20.96 °C
Average 5.78 mg/L 25.94 °C

Lower Mattaponi

June 2019 monitoring data was unavailable due to replacement and repositioning of the logger to a more secure location in early July 2019.