Stream Data

Stream Data

Citizen monitors have been measuring the water quality parameters of local creeks in Sonoma County since 2003. By monitoring local creeks and rivers, citizen monitors learn about their watershed, help pinpoint pollution sources, and identify widespread problems.

Choose a stream to see graphs of the collected data. Water quality parameters and what they can tell us are explained in detail in the CCWI Citizen Monitoring Handbook and summarized below.

  • Streams

  • Parameters

Water Quality Parameters

Electrical Conductivity
Conductivity is the ability of water to conduct an electrical current through dissolved ions in the water. It increases when temperature rises or when clay soil is washed into streams. Conductivity can be an indicator of failing sewage or septic systems or agricultural runoff.

Units: microSiemens per centimeter (µS/cm)
Levels: Streams with healthy fisheries: 150 to 500 µS/cm

Dissolved Oxygen (DO)
“DO” is the amount of dissolved oxygen in water. Most aquatic organisms need oxygen to survive and grow.Bacteria consume DO and release CO2 in the process of breaking down substances such as yard clippings, sewage, oil, and dead organic material. DO can become too low to support life when water contains too much decaying plant matter or water temperature gets too high.

Units: milligrams of oxygen in a liter of water (mg/L)
Levels: For most life to survive: DO must be above 3mg/L
To support fish: DO should be above 7mg/L

pH measures how acidic or basic the water is on a scale from 0 to 14. The type of rock in the stream bottom and presence of algae can affect pH; human-caused factors like acid rain or sulfate fertilizers can acidify water and reduce pH. Aquatic life can only survive in a narrow pH range.

Units: Scale from 0 (max acidity) through 7 (neutral) to 14(max basic).
Levels: Basin Plan Objective (North Bay): pH of 6.5 to 8.5

Water Temperature
Temperature is a measure of the average energy (kinetic) of water molecules. Temperature affects water chemistry and the functions of aquatic organisms. Water temperature changes with the seasons. Increases in water temperature can also be caused by removal of shade vegetation, reduction in stream flow, discharge of cold bottom water from dams and increase in sediment (turbidity).

Units: Degrees Celsius (C) or Fahrenheit (F)
Levels: Optimum range for salmonids is from 0°C to 16°C. Above 16°C salmonids are stressed, while the lethal limit is around 24°C.

Turbidity measures the amount of suspended particles such as algae, sediment, or organic matter in water. Turbidity can be observed directly as cloudiness in water, with higher cloudiness corresponding to higher turbidity. Turbidity is usually low (5 NTU) outside of rainy periods and goes up (into the 100’s NTU) during and after storms. High flows, eroding soils and algae increase turbidity. Human-caused factors include logging, conversion of land to agriculture, removal of vegetation, too rapid channeling of stormwater off of land and erosion of dirt roads. Excess turbidity from soil reduces light, which decreases plant life.

Units: NTUs (Nephelometric Turbidity Units)
Levels: General aquatic life needs clear water, with turbidity under 25 NTU. Salmonids prefer turbidity of less than 10NTU.

Stream Flow
Stream flow is the volume of water that moves past a fixed point during a given period of time. High flows can dilute pollutants but stir up sediment. Streams with low flows can more easily become degraded and too hot.

Units: Cubic feet per second (cfs or ft3/sec)
Levels: Aquatic life needs a variety of flow environments, from quiet pools to fast-flowing rivers. The right level of flow is crucial for salmon spawning and this is often affected by human activities such as diverting water from streams or releasing water from dams.