The water cycle is a gigantic circulation system operating over the earth's land and oceans in the atmosphere surrounding the earth.  Being a cycle, there is no beginning or ending but for illustration, let's begin with the waters of the oceans, which cover about three-fourths of the earth.

Water from the surface of the ocean evaporates into the atmosphere.  That moisture in turn is lifted, eventually is condensed, and falls back to the earth's surface as precipitation.

Precipitation that falls as rain, hail, dew, snow, or sleet is important to people and agriculture.  After wetting the foliage and ground, some of the precipitation runs off into streams and other waterways.  This is the water that often causes erosion and is the main contributor to floods.  Not all of the precipitation runs off.V Some soaks into the ground (infiltration) and is available for evaporation.  Some of it reaches the deeper zones and slowly percolates through to springs and seeps to maintain and replenish them during dry periods.  The streams eventually lead back to the oceans, where the water is again evaporated into the atmosphere.

1. Review the water cycle paying particular attention to the following nine vocabulary words:  evaporation, condensation, cloud, precipitation, river, percolation, groundwater, evapotranspiration, and water cycle.



2. Divide the class into teams of ~9 students.  Show the class a water cycle poster, pointing out that the identifying words have been hidden.  Explain that they will identify the blanks with the missing words in the course of the water cycle relay race.



3. Have the students line up in a single line.  Pass out a spoon and a tray of ice cubes to each team and have each team place them at the end of the line.  As part of the relay, each team will place an ice cube on the spoon and pass both from the back of the line to the front of the line.



4. Give each team a set of the nine vocabulary words written on slips of paper.  Have the teams attach a piece of tape to each slip of paper.  Ask the teams to discuss the words, review their meanings, and decide where they are located on the water cycle poster.



5. Read a water cycle riddle to the class.  The students must quietly decide among their team which word best fits the riddle.  The last person in line tapes the slip of paper with the matching word to the bottom of the spoon and places the ice cube in the spoon.  He or she then passes the spoon with the ice cube to the person in front of them, and so on down the line.  The person at the head of the line walks quickly to the poster at the front of the room with the spoon and ice cube, places the ice cube in a bucket under the water cycle poster, tapes the word to the correct spot on the poster, and returns to the end of the line.  The race continues with another riddle, until all the riddles have been read.



6. Before beginning the race, review the rules for the relay:  1) No one may touch the ice cube after it has been placed on the spoon until it reaches the bucket.  2) If the ice cube falls off the spoon, the back person must put the ice cube back on the spoon, and the process starts again.



7. Invite the students to help decide how points should be awarded and keep track of the scores.  Ask them to decide the number of points to be given to the team that finishes first, the team(s) that selects the correct vocabulary word, and the team(s) that correctly places the word on the poster.



8. The team with the most points wins.