About the Stream Monitoring

What is monitoring?

Gathering of information or data on a regular basis

Why monitor?

  • Learn about the stream ecosystem
  • Educate the community about the impacts of human activities
  • Provide a baseline of data to look at trends over time
  • Determine if stream health supports the water uses
  • Provide information that can be used for watershed management decisions.

All life depends on water to survive. We have limited amount of water to support life so we must protect our water resources.

Water cycle

Continuous movement of water on, below, and above the surface of the earth. The water we have here on earth has always been here – it doesn’t go away, it moves through a continuous cycle of change in form (solid, liquid, gas) and in location.

Water properties

Water has several unique properties

  • universal solvent – more substances can be dissolved in water than any other substance. This is important especially when considering storm water and impacts to streams.
  • Water molecules are attracted to each other (cohesion) and to other substances (adhesion).
  • Pure water has a neutral pH
  • Water naturally occurs as a liquid, solid, and gas

Water quality is a term that is used to describe the chemical, physical, and biological characteristics of water usually in reference to how it is being used. Quality of water can be degraded by pollution that enters the stream from both human activities and natural causes.

There are two sources of stream pollution – point source pollution and non point source pollution. Water quality can also be affected by water quantity as concentrations of pollutants are influenced by stream flow.

Sampling procedure

  • Collect in the stream in or as close as possible to the main current.
  • Collect upstream of where you enter the stream
  • Rinse the sample container 3 times before collecting sample
  • Collect sample below surface of water.

Basic Parameters Measured

Water temperature

Most aquatic organisms are “cold blooded” and their body temperatures are determined by the surrounding water. Each organism has a preferred temperature range. Temperature controls the rate of metabolism, growth, and photosynthesis. Temperature also determines the amount of oxygen in water.

Dissolved oxygen

Lack of oxygen limits what can live in the stream. DO diffuses into water from the atmosphere. Riffles, rapids, waterfalls have increased surface area for diffusion of oxygen. Photosynthesis, respiration, decomposition affect levels.


Measure of concentration of Hydrogen ions – how acid or basic a solution is. Most life is adapted to a very narrow range of ph – around 7. pH is measured on a scale of 0 to 14. There are many natural processes that affect pH – surrounding geology, photosynthesis, decomposition.


One of the two main limiting nutrients in an aquatic system. Nitrogen is a basic building block required by all life. In a natural system it is present in very small amounts and once it is used up growth will be limited. A little nitrogen is a good thing but too much can create problems.


Measure of water clarity. Turbidity is affected by sediment, algae, and other substances found in the water. Too much turbidity will limit the amount of light and limit plant growth. Turbidity in the form of sediment can smother salmon eggs, coat fish gills making it difficult for fish to breathe.

Environmental sampling by its nature must be repetitive over long periods of time to provide enough data to tease out changes and trends in water quality.