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 the data collected from Stony Creek between September 2021 and November 2021. Note the spikes (or drops) in certain parameters corresponding to weather events such as heavy precipitation or temperature changes. This cycle had several precipitation events that can be seen most clearly on the Conductivity and Turbidity chart but also as pH decreases on the pH chart.”
Click graph images to enlarge
pH is the measure of basic or acidic qualities of the stream. Typical stream pH is between 6.0 and 8.0. On this chart, several drops in pH associated with rain events can be seen.
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 cooler water temperatures. Missing dissolved oxygen data was the result of debris on the sensor.
This chart shows stream conductivity and turbidity. Conductivity and turbidity show greatest changes due to weather events washing material into the stream or disturbing the streambed and banks. Several rain events can be seen on this chart.
1451 Peters Mountain Road Dauphin PA 17018 phone: 717-921-8100