Gottgens: Aquatic Ecology Lab EEES 4740/5740/7740
Stream flow, profile, and discharge of solids and nutrients in an urban river
[We will also do some seining for fish in the river to demonstrate field techniques used to study
ichtyofauna and to link river water quality with fish community composition . We may even look
at other biota as well while we’re there…..]
Location: Ottawa River near campus
(we may move to a different location if water levels are too high)
Streams collect and transport water, dissolved substances, and suspended particles from
their drainage basin. The characteristics of a stream, therefore, are a reflection of different
aspects of the drainage area. Such aspects include climate, geology, plant cover, and human
impact. Streams are very dynamic systems. The flow of water and its chemical and biological
composition may vary greatly over time in response to storm events, seasonal rainfall, annual dry
spells, changes in land use, etc. Entire stream channels may shift gradually over years in
response to scouring of banks and redeposition of sediments. Streams are also quite
heterogeneous with areas of shade and sun, and pools of relatively slow moving water separated
by riffles of turbulent water. They form connections between water bodies and have been used
and abused by humans as a convenient conduit for the dumping of waste.
This laboratory exercise is primarily aimed at learning how to measure stream velocity
and discharge and how to use these measurements to develop a stage-discharge relationship for
the stream. By determining the concentration of total dissolved solids (TDS), total suspended
solids (TSS) and total phosphorus (TP) you will also be able to calculate the discharge of these
materials (and any other ones for which you have measured the concentration). Later in the
semester we will study stream ecology in class and compare flora and fauna in different areas of
a stream.
During this lab exercise, you will determine cross-sectional area and stream flow at two
different stations. We will also measure the concentration of the water quality parameters
mentioned above. You are asked to compute the stream discharge (m3/sec) at each of the two
stations, calculate the discharge of each of the water quality parameters (kg/day), estimate a
number of stream characteristics (including peak discharge), and answer a number of short
questions. Results are to be presented in a short written (word-processed) report due (October 5)
following the completion of laboratory analyses of the water samples (September 14). The
format for this report is given below.
The protocols for the laboratory analyses to measure the concentration of water quality
parameters will be provided prior to the September 14 lab.
Stream flow, profile and discharge laboratory report.
Prepare a short laboratory report (word-processed; about 2 pages excluding tables and
graphs) using your field notes and the results of your field measurements. The report should, at a
minimum, contain the following information.
(1) Introduction
Briefly introduce the topic and the significance of this exercise. State the goal of this lab.
(2) Materials and Methods
When appropriate, refer to your handouts (no need to repeat this information). Be sure to
describe all modifications you applied.
(3) Results
Present the following results for both stations (show your calculations);
 Stream cross-sectional areas (m2) and total cross-sectional area
 Flow measurements (m/sec),
 Total stream discharges of water (in m3/sec)
 Results of the analyses for TDS, TSS, and TP. Report the values both in units of
mass/volume (kg/m3) and mass/time (kg/day).
 It is expected that the results will be presented in tables using a standard spreadsheet
program.
(4) Discussion
Examine your results, discuss the differences between both stream stations, and answer the
following questions:
 What are some of the causes of the variability in discharge (water, TSS, TDS, or TP)
among the two stations? How would you improve the accuracy in these measurements?
 Streams have a highly variable discharge at different times of the year (remember the
mudline and debris on trees adjacent to this stream). Give a rough estimate of the
discharge of water (in m3/sec) and total suspended solids (in kg/day) through the river as
judged by these field indicators during high stage conditions. Assume that the flow (m/s)
at these high stages is one order of magnitude (10x) faster than at the stage you measured
during the lab.
 Suppose that you are under contract to quantify the annual stream discharge of this river.
Your budget, however, will only allow you to determine stream cross-sectional area, flow
and stage ten times during that year. This is insufficient to characterize the annual
discharge. Describe the approach you would use in this case. You may assume that the
bottom contour of the stream is stable.
 The amount of suspended or dissolved material in the water fluctuates greatly and is
highest during and immediately after storm events. How would you design your
sampling program to include these fluctuations?
(5) References
Only list references you cited in the report. Use a consistent citation style.