Deborah L. Turnbull
The School-Site Watershed: Puddle Study
Objectives
To investigate the flow of surface water on the school grounds as related to larger watersheds, and to teach keying and mapping skills. Make special note that the surface flow of water is only a small portion of the total flow.
Field Site
The immediate environment of the school, preferably recently after a rain storm. If you cannot go outside, construct a watershed from paper, gluing objects to the paper (the waterways, houses, hills, urban areas, etc.). Have the students use the key side of the paper to make a key for each object glued on and proceed as below.
Materials
Pencils
Paper
Transit boards, an example of which can be found in the Teacher’s Box.
Procedure
The transit boards are constructed by taking a square piece of board approximately 8” x 8” (use peg board, styrofoam, or other soft wood), a piece of string marked at one-foot intervals, divide the first foot evenly into two-inch intervals. Attach the string to the middle of any edge of the board with a tack or a piece of tape.
To do this exercise, the paper should be folded in the following manner: take a sheet pf paper 8 1/2” x 11”, fold one third of the paper over. This leaves a place for students to take notes on the area of land they are mapping. If you are investigating a tide pool or other areas where you expect to find organisms, fold that side panel over in half and label as organisms and number found.
(figure available in print form)
(figure available in print form)
(figure available in print form)
After introducing the watershed concept, explore the school site and discuss drainage of rainfall from the school grounds. Have small groups list sites where water is drained, including all drain pipes, gutters, storm drains, streams and ditches. This could lead to a number of different mapping activities.
Where are the puddles found? These puddles can be explored in a number of ways. One way is to use the transit boards you have constructed. If you desire to just map water flow, divide students into groups of two. Have one student hold the board and be the recorder. That student is responsible for recording spot to scale that the second student calls out. The second student walks the line to points of inflow of water into the puddle. Since the board can translate the angle by virtue of the string placement, and the one-foot to 2” scale tells the length, you can translate the puddle watershed onto your piece of paper. If your puddle contains plants and animals, have the students make a key on the side of the sheet of paper. Use the symbol decided upon to make the spot on your sheet of paper. Your limitation to size of the area mapped is determined by the length of string and the size of your board.
Obtain a topographic map which contains your school to use with your class in identifying wetland areas and outlining small watersheds. You may wish to teach a lesson in reading and interpretation of map symbols. It could be a lesson in math by discussing heights and depths with the use of contour lines. A compass is valuable for learning about maps and seeing how useful they can be. The compass is, in itself, a good way to discuss direction and basic geometry skills. Use the map to locate the watershed of the school from the slopes, hills, and mountains of the area which drain down into it.