Score 4: Exploring Your Watershed
Teacher Instructions
Defining Your School Watershed & Its Pollutant Sources
Objectives: In this 3-part lesson students will




Explain the difference between nonpoint- and point-source
pollution and the relevance of stormwater pollution.
Define the school watershed on a topographic map.
(Alternative: if this is too challenging for your grade level, use
the Score Four Maryland Fieldscope Lesson.)
Investigate land-use and stormwater pollution sources in the
watershed.
Do water chemistry testing on stormwater runoff.
Background: Nonpoint source pollution is a primary factor in the
decline of the Chesapeake Bay Ecosystem. Nutrients and sediments
cause eutrophication in the Chesapeake Bay and river sections.
Eutrophication has resulted in hypoxic areas – so called dead zones
where oxygen levels are so low that most aquatic life cannot survive.
Stormwater runoff is the fastest growing source of nutrients,
sediments, and other pollutants entering the Chesapeake Bay and her
tributaries.
Prior Knowledge: Students should have basic knowledge of the
Chesapeake Bay’s location, the negative effects of pollutants, and that
biodiversity in the Bay is faltering due to human impacts. If needed,
use the PowerPoint: Score Four: Watersheds, Landuse, Pollution, and
Solutions.
Materials Needed: topographic map of the school’s watershed from
http://nationalmap.gov/ustopo; maps of land-use near the school;
Watersafe Science Project kit ($40).
_________________________________________
Grades: 10-12, parts adaptable
for lower grades.
Time: 3-part lesson: topographic
mapping - 60 minutes; mapping
investigations - 15 minutes;
stormwater chemistry - 60-90
minutes.
Skills Exercised: Mapping
skills, computer skills, water
chemistry, critical thinking –
making inferences from data.
Standards Met:
Next Generation Science
Standards: Earth Systems HSESS2-2, Ecosystems: Interactions,
Energy, and Dynamics HS-LS2-7.
Maryland State Law: COMAR
13A.03.02, COMAR 13A.04.17.01
Maryland Environmental Literacy:
Standard 1: Environmental Issues
Topic A, Standard 5 Humans and
Natural Resources: Topics A and B,
and Standard 8 Sustainability:
Topics A, B, and F.
MD Core Learning Goals: Goal 6
Environmental Science 6.2.2 (this
lesson can expand upon), 6.2.3,
and 6.4
Lesson Overview
Note: this 3-part
lesson provides a
presentation and
2 student
handouts,
provided at the
end of this
overview.
A Prezi presentation introduces each of the lesson parts, as well as a
concluding video about a youth restoration project. The presentation was
developed for St. Mary’s County, Maryland, and thus, uses maps from that
county. Teachers may substitute maps of their own areas.
http://prezi.com/zovrvoopip7n/score-4-workshop-2015/
Introductory Video and Discussion (5 minutes)
A two-minute Chesapeake Bay Foundation video on the Prezi presentation is
designed to initiate student discussion of stormwater pollution.
Teachers: Explain the difference between point and nonpoint source (NPS)
pollution and introduce the 3 lesson components. NPS pollution, unlike pollution from industrial and
sewage treatment plants, comes from many diffuse sources. As runoff from rainfall or snowmelt flows
over and through the ground, it picks up and carries human-made pollutants, finally depositing them
into lakes, rivers, wetlands, coastal waters, and ground water. In urban areas with vast areas of
Whitney D. Rupard
St. Mary’s College of Maryland SMP 2015
Score 4: Exploring Your Watershed
Teacher Instructions
impermeable surfaces precipitation cannot infiltrate into the ground; the excessive runoff is called
stormwater runoff. In the following activities students can determine what types of contaminants
might be flowing into local waterways from runoff by investigating their watershed and the land uses in
their watershed.
Segment 1: How to Read a Topographic Map and Delineate a Watershed
o
Preparation: Download a topographic map of the school’s watershed at:
http://nationalmap.gov/ustopo.
o In the left hand column, click on “Download Maps (Map Store).” Then use the search bar
to find your school. To download, click on the location marker to view available maps.
Download the most recent map available.
Provide students with the “How to Read a Topographic Map and Delineate a Watershed”
handout. Using the next part of the Prezi presentation, go over the handout to help the
students understand what the maps mean and the steps in delineating a watershed.
Provide pairs of students with copies of the school’s topographic map and have them delineate
the watershed, following the instructions in the handout.
Have the class share their results and any problems encountered in the process.
Compare the delineated watershed to the watershed areas found on:
o
o
o
o
http://www.cbf.org/about-the-bay/maps/fieldscope.
Segment 2: Investigate Land Use Maps
o
For schools in Maryland, a land-use map is available at:
http://mdpgis.mdp.state.md.us/landuse/imap/index.html
Search for your school in the search bar.
o
For schools in other states, land-use information may be found on the Chesapeake Bay
Fieldscope or search for land-use maps for your county.
o
Provide copies of the land-use maps to your students or work as a class to examine the maps.
Have the students list the different types of land uses by the largest use to the smallest, using
percentages found in the map database. They should discuss and list possible contaminants
from the different land-use areas. Some examples follow. Segment 3 will enable them to add
to their list of contaminants.

Agriculture or livestock – fertilizer, pesticides, sediment, animal wastes, hormones.

Housing developments and urban areas – car fluids, garden fertilizer, pest control,
septic systems, and detergents, to name a few.

Impervious surfaces – deicers, exhaust, gasoline, oil, asphalt (PAH).
Segment 3: Watersafe Science Project Kit
o
Students view the Prezi presentation, Part 2, and read the Watersafe Science Project
information on water chemistry water quality indicators and pollution sources.

The students will add to or amend the information listed during Segment 2.

Then the class or student teams will create a hypothesis (or multiple hypotheses)
about the types of contaminants in your school’s stormwater runoff. This can be
recorded in the Watersafe Science Project Kit student handout.
Whitney D. Rupard
St. Mary’s College of Maryland SMP 2015
Score 4: Exploring Your Watershed
Teacher Instructions
o
Students will investigate the nonpoint source contaminants found in stormwater runoff and
compare the results to their hypotheses. The student handout provide information on types
of nutrients and pollutants, and will be where students can record their data.
o
You will need a Watersafe Science Project kit ($40), which may be ordered from:
http://www.americanscreeningcorp.com/watersafe-science-project-4-pack-p3048.aspx.
The Watersafe Science Project Kit will test water for: lead, bacteria, pesticides, nitrates,
nitrites, chlorine, hardness, and pH. It is recommended that your students work in groups to
test for each property. The bacteria test takes 48 hours and the containers should be
labeled appropriately. As students perform the tests, they will make notes and write down
their results. Refer to the student handout.
o
Discuss the results with the class and draw connections between the surrounding land uses.
Was the class hypothesis correct? Why or why not? Is more follow-up research needed?
Concluding Prezi Presentation
View a short video about an Alliance for the Chesapeake Bay youth restoration project
to reduce stormwater pollution to inspire students to think about what they could do at
the school or in their communities.
Whitney D. Rupard
St. Mary’s College of Maryland SMP 2015
Score 4: Exploring Your Watershed
Student Handout
How to Read a Topographic Map and Delineate a Watershed
Interpreting Topographic Maps
Basic Concepts:
Contour interval is the difference in elevation between two adjacent contours. Typically this is given in the map
legend. It represents the vertical distance you would need to climb or descend from one contour to the next.
Contour lines represent a ground elevation or vertical distance above a reference point such as sea level. All points
along a contour line are at the same elevation .
Hill. A hill is an area of high ground. From a hilltop, the ground slopes down in all directions. A hill is shown on a
map by contour lines forming concentric circles. The inside of the smallest closed circle is the hilltop
Whitney D. Rupard
St. Mary’s College of Maryland SMP 2015
Score 4: Exploring Your Watershed
Saddle. A saddle is a dip or low point between two areas of higher ground. A saddle is not necessarily the lower
ground between two hilltops; it may be simply a dip or break along a level ridge crest. If you are in a saddle, there
is high ground in two opposite directions and lower ground in the other two directions. A saddle is normally
represented as an hourglass.
Valley. A valley is a stretched-out groove in the land, usually formed by streams or rivers. A valley begins with high
ground on three sides, and usually has a course of running water through it. If standing in a valley, three directions
offer high ground, while the fourth direction offers low ground. Depending on its size and where a person is
standing, it may not be obvious that there is high ground in the third direction, but water flows from higher to
lower ground. Contour lines forming a valley are either U-shaped or V-shaped. To determine the direction water is
flowing, look at the contour lines. The closed end of the contour line (U or V) always points upstream or toward
high ground.
Ridge. A ridge is a sloping line of high ground. If you are standing on the centerline of a ridge, you will normally
have low ground in three directions and high ground in one direction with varying degrees of slope. If you cross a
ridge at right angles, you will climb steeply to the crest and then descend steeply to the base. When you move
along the path of the ridge, depending on the geographic location, there may be either an almost unnoticeable
slope or a very obvious incline. Contour lines forming a ridge tend to be U-shaped or V-shaped. The closed end of
the contour line points away from high ground.
Information provided by US Army Field Manual "Map Reading and Land Navigation" ©
Educational use ONLY.
Whitney D. Rupard
St. Mary’s College of Maryland SMP 2015
Score 4: Exploring Your Watershed
Delineating a Watershed
The following procedure and example will help you locate and connect a watershed’s high points on a topographic
map (Figure E-4). Use the following method to visualize the landscape represented by the topographic map.
1.
2.
3.
4.
Draw a circle at the water outlet or the downstream point that eventually will lead to a larger body of
water. For example, see Figure E-4.
Put small "X's" at the high points along both sides of the watercourse using the information you learned in
this worksheet. Work your way upstream towards the headwaters (beginning of the tributary) of the
watershed.
Starting at the circle that was made in step one, draw a line connecting the "X's" (Figure E-5).
- This line should always cross the contours at right angles, perpendicular to each contour line it
crosses.
- End back where you started, the stream outlet.
This area is your designated watershed.
The delineation (Figure E-5) appears as a solid line around the watercourse. Rain falling anywhere in this area will
either evaporate, infiltrate into the ground, or runoff to the stream and to its downstream point. Different land
uses in this area affect the amount of runoff that reaches the stream, the speed at which it reaches the stream,
and the amount of pollution it carries. Explain why this is true, giving two examples.
This fact sheet is adapted from Appendix E of the Method for the Comparative Evaluation of Nontidal Wetlands in New Hampshire, 1991. Alan Ammann, PhD and Amanda Lindley Stone. This
document and method is commonly called “The New Hampshire Method.”
Whitney D. Rupard
St. Mary’s College of Maryland SMP 2015
Score 4: Exploring Your Watershed
Whitney D. Rupard
St. Mary’s College of Maryland SMP 2015
Score 4: Exploring Your Watershed
Student Handout
Watersafe Science Project
Background
After reading about common water pollutants below, you will use maps, water chemistry kits, and critical
thinking to answer these questions:
What types of nutrients and other pollutants can be measured in a watershed? Where do they come
from? What harm do they cause to the tributaries of the Chesapeake Bay?
Nitrogen (N): Nitrogen is an essential nutrient for plants and animals, but an
excess of nitrogen in our waterways harms aquatic ecosystems. Nitrogen (in
the forms of nitrites, or NO2, and nitrates, NO3) enters water from runoff
carrying farm animal manure, field fertilizers, and human wastes, as well as
from vehicle exhaust in the air. Excess nitrites and nitrates water greatly
increase the growth of algae. Masses of algae block sunlight from
underwater plants, and when the algae masses die, their decomposition uses
oxygen. Both these factors are part of a process known as eutrophication,
which depletes oxygen in the water. Zones in water bodies with very low
levels of oxygen are called hypoxic, or dead zones, because fish, oysters, and
most other aquatic organisms cannot survive in these areas (USF, 2000).
Phosphorus (P): Phosphorus, released from soils and weathered rocks, is
another naturally occurring essential nutrient for plants and animals.
Elevated levels of phosphorus in water bodies are caused by human activities
and lead to increased algae growth and eutrophication. The largest source of
phosphorus pollution is agricultural runoff from mineral fertilizers and
animal waste. Other sources include industrial wastes, home fertilizers, and
lawn clippings. (Watersafe, 2015)
Carbon Dioxide (CO2): Carbon dioxide is absorbed by surface waters. As the
burning of fossil fuels has boosted carbon dioxide in our atmosphere, the
levels of carbon dioxide in our oceans and estuaries, such as the Chesapeake
Bay, also have increased. Part of the carbon dioxide reacts with the alkaline
water, forming carbonic acid. The increased acidity of the water is
detrimental to aquatic species, especially to animals with calcium carbonate
shells, such as oysters and coral, because it triggers buffering reactions that
use the carbonate minerals needed for shell building. (NOAA, 2015)
pH: pH is a measure of a water’s acid/base content (H+ and OH- ions),
measured on pH units on a scale of 0 to 14. The pH level of a water body is
influenced by the concentration of acids in rain and the types of soils in the
bedrock. Most fish require waters with a pH of 6.2 to 8.2 to reproduce and
survive. Increased levels of pH from anthropogenic sources include acid mine
drainage from mines, known as acid mine drainage, and emissions from coalburning plants, causing what is commonly called acid rain.
Author: Whitney D. Rupard , St. Mary’s College of Maryland SMP © 2015; Edits by ICPRB for Score Four.
Score 4: Exploring Your Watershed
Student Handout
Bacteria: Bacteria in our waters can lead to diseases in humans and aquatic
life. Fecal coliform bacteria from pets, farm animals, and human waste enter
rivers via stormwater runoff and combined storm-sewer system could be
present. Another recent concern is the increase in incidences of lifethreatening bacteria vibrio infections in humans and seafood, likely caused
by warmer waters.
Pesticides & Herbicides: Pesticides are chemicals used to eliminate weeds,
insects and other harmful elements in crops and home gardens. Their
pervasive use, however, has produced its own harm to native plants and
insects. It is not uncommon to find pesticide contamination even in our
drinking water. (Watersafe, 2015)
Salinity: Salinity is the total of all salts dissolved in water, usually expressed
as parts per thousand (ppt). In an estuary, such as the Chesapeake Bay, the
flow of fresh water from streams and rivers mixes with salty ocean water,
producing a range of salinity from 1 to 35 ppt. Water salt content affects the
distribution of animal and plant species according to the amount of salinity
they can tolerate. Brackish waters, such as the tidal portions of the Potomac
River, range from 10 ppt to 1 ppt salinity. Freshwater streams should have 0
ppt salinity, but their salinity (or chloride levels) can be elevated by
pollutants, such as road salt (sodium chloride) and industrial waste. The
accumulation and persistence of chloride in fresh water poses a risk to the
plants, animals, and humans who depend upon it.
Author: Whitney D. Rupard , St. Mary’s College of Maryland SMP © 2015; Edits by ICPRB for Score Four.
Score 4: Exploring Your Watershed
Student Handout
Testing Nutrients and Pollutants in your School’s Watershed
After reading about pollution sources, observe a land use map of the area surrounding your school, what
types of contaminants do you expect to find in your school’s watershed? (For Maryland areas, see this site
for land-use maps: http://planning.maryland.gov/OurWork/landuse.shtml
Observations in your School’s Watershed
You can observe a stream near your school, a stormwater pond, or stormwater that has collected after a
storm. Observe and record information about the areas you are testing. Include variables that might affect
your results. Include the following.






What type of water source and its location
Clarity of water
Land cover (vegetation, pavement, etc.) in surrounding the area
Presence of living organisms
Weather
Human impacts
Author: Whitney D. Rupard , St. Mary’s College of Maryland SMP © 2015; Edits by ICPRB for Score Four.
Score 4: Exploring Your Watershed
Student Handout
Total Nitrate/Nitrite
Record the results of your sample in ppm (parts per million units).
*End of the test strip
1. Carefully open Nitrate/Nitrite Test packet and packet and take out test strip.
2. Immerse the reagent pads into water sample for 2 seconds, and then remove. After 1 minute match
colors to chart below.
3. Colors are stable for 1 minute.
Nitrites
Record the results of your sample in ppm (parts per million units).
*Nearest to test strip handle
Author: Whitney D. Rupard , St. Mary’s College of Maryland SMP © 2015; Edits by ICPRB for Score Four.
Score 4: Exploring Your Watershed
Student Handout
Bacteria
Record the results for each sample as negative or positive for bacteria detection.
1) Take out the Bacteria Test vial and set upright on a flat surface.
2) Collect water sample or turn on tap to a very slow stream.
3) Carefully twist off cap and fill vial to 1⁄2 inch below the top (to 5 ml line).
DO NOT OVERFILL and DO NOT SPILL the bacterial growth powder in the vial.
4) Replace the cap and twist on tightly. Shake the vial vigorously for 20 seconds.
5) Place the capped vial upright in an area 70-90 °F where it cannot be disturbed for 48 hrs.
6) After 48 hours, observe the color of the liquid without opening the vial:
a. Purple Color: Negative Result
b. Yellow Color: Positive Result
*It is highly likely that potentially harmful bacteria were detected
Pesticides and Lead
Record the results for each sample as negative or positive for pesticides detected.
The Lead/Pesticide Test detects dissolved lead at levels below the EPA Action level of 15 parts per billion
(ppb) and two of the most common pesticides used in the US at or below the EPA Maximum Contaminant
Level (atrazine – 3 ppb, and simazine – 4 ppb).
1) Open Lead/Pesticide packet and take out all contents. The packet contains a test vial, a dropper
pipette, and two test strips.
2) Using dropper, place exactly TWO dropper-fuls of water sample into test vial. To pick up sample,
tightly squeeze the bulb at the end of the dropper and place the open end into water sample.
Release the bulb to pick up sample, then squeeze again to expel sample
3) Swirl gently for several seconds. Place on a flat surface.
4) Place both test strips into the test vial, with arrows pointing DOWN.
5) Wait 10 minutes. Do not disturb strips or vial during this time. Blue lines will appear on the strips.
6) Take the strips out of the vial and lay them on a flat surface with the arrows pointing to the LEFT.
Read Results.
Negative: LEFT line (next to number 1) is darker than the RIGHT line (next to number 2).
Author: Whitney D. Rupard , St. Mary’s College of Maryland SMP © 2015; Edits by ICPRB for Score Four.
Score 4: Exploring Your Watershed
Student Handout
Positive: RIGHT line (next to number 2) is darker than LEFT line (next to number 1), or lines are
equally dark (Both LEFT and RIGHT lines are equally dark)
*Note: If no lines appear, or both lines are very light, the test did not run properly, and the results are not
valid.
If a test strip shows a positive result, your water sample may contain lead or pesticides at a toxic level.
pH
Record the results of your sample in pH units based on the color chart (end of strip).
1) Carefully open pH / Hardness / Chlorine Test packet and take out test strip.
2) Immerse the reagent strips into water sample and remove immediately. Hold the strip level for 15
seconds.
3) Match pH, Total Hardness and Total Chlorine strips (in that order) to the color chart.
Hardness
Compare your results in the middle of the strip to the color chart.
Record the results of your sample in ppm (parts per million units).
Author: Whitney D. Rupard , St. Mary’s College of Maryland SMP © 2015; Edits by ICPRB for Score Four.
Score 4: Exploring Your Watershed
Student Handout
Chlorine
Compare your results on the strip nearest the handle to the color chart .
Record the level of chlorine in your sample in ppm (parts per million units).
Water Test Desired Values
EPA maximum contaminant levels or guideline standards
Author: Whitney D. Rupard , St. Mary’s College of Maryland SMP © 2015; Edits by ICPRB for Score Four.
Score 4: Exploring Your Watershed
Topographic Lesson and Stormwater Chemistry Bibliography
NOAA PMEL. (2015, 3 5). PMEL Carbon Program. (NOAA, Producer) Retrieved 3 5, 2015, from What Is
Ocean Acidification?: http://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F
Silver Lake Research. (2015, 3 5). Watersafe. Watersafe- Drinking Water Test . Monrovia, CA, USA: Silver
Lake Research.
University of South Florida. (2000, 0 0). Project Oceanography. Neighborhood Water Quality . Tampa, FL,
USA.
Graphics:
Cow- http://2047502.fortunecity.ws/cow.gif
Smoke Stackhttp://us.cdn1.123rf.com/168nwm/konstantinks/konstantinks1410/konstantinks141000322/32548099factory-icon-on-white-background-vectorillustration.jpg
Mountain- http://images.clipartpanda.com/mountain-clip-art-10863-black-and-white-mountaindesign.png
pH- https://s-media-cache-ak0.pinimg.com/236x/98/18/f0/9818f0d46579b8026e110639a7b92c1d.jpg
Microscope- http://pixabay.com/static/uploads/photo/2014/03/24/13/44/microscope-294185_640.png
Dishes- http://www.signspecialist.com/decals/beevault/images/Cleaning%20023-0095.gif
Lead- http://sr.photos2.fotosearch.com/bthumb/UNC/UNC311/u13362020.jpg
Spray- http://pixabay.com/static/uploads/photo/2012/04/01/19/51/spray-24302_150.png
Bleach- https://i0.wp.com/www.angelofoz.com/bleach_hints/bleach%20bottle.gif
Whitney D. Rupard
St. Mary’s College of Maryland SMP © 2015