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Waterbasins and Watersheds Lesson Plan

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Lesson Plan #: AELP-GLG0052
Submitted by: Yvonne Bowser
Email: yehallbowser@yahoo.com
School/University/Affiliation: University of Pittsburgh @ Johnstown
Date: January 28, 2000

Grade Level(s): 8, 9, 10, 11, 12


  • Science/Geology
  • Science/Environmental Education

Duration: minimum one 45 minute session, best suited for two 45-min sessions Description: Students will define waterbasins and watersheds, then delineate the boundaries of their local waterbasin/shed using maps.

Goals: Pennsylvania’s Department of Education has new Environment and Ecology standards. This lesson is intended to fulfill the section relating to watersheds, their function, importance, and the impacts humans have on them. This will fit well in most water units.

Objectives: Students will:

1. define waterbasin and watershed and give several differences.
2. draw and highlight a river system and delineate rough boundaries of the waterbasin .
3. identify which waterbasin and watershed their school is located in.
4. delineate on a topographic map the more accurate boundaries of a small watershed.


  • highlighters
  • pen
  • pencil
  • rulers
  • state map
  • topographic maps of area
  • clear plastic sheets
  • dry erase markers
  • computer access for teacher and students with Internet access

Procedure: Anticipation Guide Questions:

1. Agree or Disagree: Our community has a safe water supply.
2. Agree or Disagree: There is enough clean water in nearby areas to support all the people living here now and in the future.
3. Agree or Disagree: What gets dumped into or taken out of local streams and rivers is more important than what happens to the land surrounding the rivers.

Teachers may discuss anticipation questions with the class after they have filled them out, or may prefer to wait until after the lesson, discussing if answers have changed and why students agreed or disagreed.

Background and Discussion:

1. Have you ever wondered where rain goes when it falls? Stop sometime and watch a stream or river flowing by – does it end up in our drinking water? What things keep water clean in nature and in the water we drink? The land areas filter water naturally as it passes through on the surface or into ground water.
2. Waterbasins and watersheds are two ways that we classify water boundary units. Waterbasins are large land areas that are drained by a major river system. Watersheds are smaller land areas that are defined as the area that is drained by one stream or river.
3. Students can delineate or outline the land area for a waterbasin by following the course of a river from source to mouth and identifying all of the tributaries for the river. Watersheds are best delineated using a topographic map. Start by again identifying all the tributaries and intermittent streams on the topographic map (cover with the plastic sheet and use dry erase markers or call up the topographic map on the internet and screen), then every inch from the mouth to the source, draw a small line perpendicular to the stream. Using your ruler follow that perpendicular line until you hit the highest elevation and mark it with a dot. Do this on either side of the stream for each mark. Connecting the dots along lines of highest elevation will delineate the watershed.

Pupil Investigations:

1. When it rains here, where does the water go? (ground water, runoff, evaporates, etc..) What bodies of water are located near here?
2. In groups, take out your state map and locate the Chesapeake Bay. Highlight it with your marker, also highlight the town we are in and the nearest stream.
3. For the next 10 minutes you will be connecting these two points, by highlighting the waterways that connect the two, you may go from either direction flowing from smaller to larger, or from large to small.
4. This is the path that our water takes as it flows toward the Atlantic Ocean. Now we want to look more specifically at where the water comes from – the land. Locate a major river that flows into the Chesapeake. Highlight ALL the smaller rivers AND every stream that flows into that major river.
5. Using your ruler draw a rough outline of the land that your highlighting encompasses. This would be the waterbasin of the __________ river.
6. How much land is included in your outline? Miles? Waterbasins are so large there are only 5 of them in Pennsylvania. (They are the Delaware, Susquehanna, Potomac, and Ohio – the there are two waterbasins we combine into one since they both flow into the Great Lakes). They are named after the major rivers that drain that land area. Now we want to look more closely at the water drainage area for this school. Where does water go when you wash your hands or shower in gym class?
7. On computers have students go to the DCNR, Bureau of TopoGeo at www.dcnr.state.pa.us/topogeo/maps&photos.htm (or check with your state’s Department of Natural Resources) Have students call up the topographic map of the local stream or river. Review specifics of topographic maps as needed.
8. On your locate the mouth of the river/stream where your water flows. If in a larger watershed, use you may wish to not include the entire watershed if it involves using several topo maps. Using +’s (or some other mark easily visible on the map) spaced at one-inch intervals, trace the flow of the stream to its source. At every mark draw a line (imaginary if necessary) perpendicular to the stream. Follow the perpendicular line until you reach the highest elevation before cresting a major ridge and make a dot (*, ^, etc…) at this point. Do this for each side of the stream.
9. When you connect the dots the line will show the delineation of your watershed that follows small topographic variations and ridge and mountaintops.
10. When students have delineated their local watershed, have them work in their groups to answer the general question below or have them complete a report on one of the five major waterbasins. In Pennsylvania, many of the answers will be available at DEP homepage, however many other resources are available online (see below).


1. How much water do Pennsylvanian’s citizens use everyday?
2. What are the 3 places in North America where PA’s water empties into an ocean?
3. Name 3 of PA’s major industries that impact our water resources?
4. Gather information on one particular waterbasin to share with the class.


Assessment may take several forms depending on the route chosen by the teacher. Students may give oral presentations on their waterbasins as groups. Students may submit written reports on their waterbasins. Review or checking of questions at the end of the exercise. All options should include discussion of the anticipation questions, emphasizing the importance of watersheds on local water availability and their effects on the flora and fauna downstream.

Useful Internet Resources:

The state of Pennsylvania has several good web resources. The Department of Environmental Protection (DEP) and the Department of Conservation and Natural Resources (DCNR) both have much of the information used to create this lesson.

Pennsylvania’s Department of Environmental Protection

The Pennsylvania Department of Conservation and Natural Resources

DEP has more laws and in depth materials used in managing the state’s water resources. DCNR, Bureau of state parks has a new curriculum called Watershed Education where lessons similar to this are located and teachers can input data from their stream investigations onto the statewide database.

Watershed Notebooks