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Dauphin County Conservation District, working in cooperation with Doc Fritchey Chapter of Trout Unlimited, has begun continuous water monitoring of Stony Creek. This effort will help to understand changes in a number of water condition parameters over short and long time durations. A stream side monitoring station utilizing a device known as a sonde measures water conditions every 15 minutes and records the data for later analysis. 

This page shows charts that compare select relevant parameters recorded by the sonde over its previous deployments. Where relevant, points of note are highlighted to demonstrate how certain events in the watershed can vary the conditions of the stream. 

The main parameters measured by the Sonde are Temperature, Turbidity, pH, Dissolved Oxygen, and Conductivity. 

  • Temperature:  Influenced by day and night air temperature cycles and sunlight reaching the stream. Temperature may lag behind air temperature as upstream temperature changes are compounded as water travels downstream. 

  • Turbidity: A measure of solid particles suspended in the water, turbidity increases with inflow of sediment and disturbances to sediment in the substrate of the stream itself.  In general terms, it is a measurement of water “cloudiness.”  Higher turbidity in a stream can smother out aquatic life needed to support a healthy ecosystem and also can harbor pathogens, increasing the intensity of water treatment for drinking water systems.

  • pH: The measure of acidity or alkalinity of the stream.  Precipitation in this region is usually acidic and rain events can lower the pH of the stream.  Current and past mining activities and abandoned mine drainage in a watershed are also known to impact the pH of streams.  Doc Fritchey Trout Unlimited treats Rauch Creek, a known acidic tributary to Stony Creek, using limestone diversion wells (Read more here http://www.dftu.org/projects/stony-creek/ )which raises the pH (reducing acidity), ultimately reducing acidity of Stony Creek. 

  • Dissolved Oxygen:  Also referred to as DO, dissolved oxygen is important to the health of a stream as it is needed to support the life processes of microbes, insects, fish and other organisms in a stream. Colder water holds more dissolved oxygen.  Sunlight increases water temperature causing a decrease in dissolved oxygen concentrations during daylight hours. Sunlight and added nutrients can also increase biological activity in the stream which can further decrease dissolved oxygen.  

  • Conductivity:  A measurement of the ability of the water to pass an electrical current, conductivity is measured to indicate the presence and concentrations dissolved minerals. Conductivity is influenced by the geology of the watershed as well as human activities.  Higher conductivity measurements are often a sign of run off from human activities such as road salting, fertilization, and mining.  Higher water temperatures allow for higher conductivity as well. 

The graphs below represent a comparison of some of the data collected from Stony Creek between late March 2017 and mid May 2017. Note the spike (or drop) in certain parameters during corresponding weather events such as heavy precipitation or temperature changes. This cycle had several precipitation events that can be seen most clearly on the Turbidity and Conductivity chart. Precipitation events of note include 4/6, 5/2, and 5/6.

Click graph images to enlarge

 pH is the measure of acidity or basicity of the stream. Typical stream pH is between 6.0 and 8.0. 

Cooler temperatures allow for higher dissolved oxygen levels resulting in a mirror-like graphical relationship.  Higher quality wooded streams typically have high dissolved oxygen levels and cool water temperatures.

 

Turbidity and conductivity are shown here together. These stream characteristics show greatest changes due to weather events washing material into the stream or disturbing the streambed and banks.  

 

 

 

 

 

 

 

 

Dauphin County Continuous Stream Monitoring Program