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Classroom activity Grade 5 Science

The Tolvern Creek Water Budget: A Gallon-Card Role-Play

Students take the roles of rain, creek, farm, wetland, and town, passing gallon cards through three rounds to model where a small creek's water goes in a dry stretch.

Objectives

  1. Students will model a creek's water budget by passing cards for rain, withdrawals, and returns.
  2. Students will track the creek's running total across three rounds and convert cards to gallons.
  3. Students will explain how a farm's change in watering kept the creek from dropping further.

Vocabulary

Watershed
A watershed is all the land where rain that falls will drain to the same stream, river, or lake. Everyone lives in a watershed, no matter how far from the water they live.
Water budget
A water budget is a way of tracking all the water coming into an area, like rain and snowmelt, against all the water leaving it, like evaporation and streamflow. Scientists use water budgets to see whether a watershed or aquifer is gaining or losing water over time.
Wetland
A wetland is an area like a marsh or swamp where the ground is soaked with water for much of the year. Wetlands soak up floodwater, help clean it, and shelter many kinds of animals.
Return flow
Water that goes back to a river or aquifer after being used, like irrigation water that soaks past the crops. Downstream users often depend on it.

Also: withdrawal

Teacher overview

Tolvern Creek is a fictional creek that runs past a farm, a wetland, and a small town, and in this role-play the class becomes those four places plus the rain above them. Each index card stands for 1,000 gallons, and every round the cards move by a fixed script, so the class can watch the creek's running total rise and fall. The card passing fits the concept well, because the places in a watershed hand water to one another, and the cards make each handoff visible. The misconception this activity addresses is the assumption that water taken from a creek is simply gone, when some of it returns through soil and wetlands after a delay, which is why the wetland role gives cards back in later rounds.

Activity Directions

Step 1, setup (10 min): Write 1,000 gallons on 40 index cards, or tell the class that every card counts as 1,000 gallons. Assign five roles and post a sign for each: Rain Cloud, Tolvern Creek, Harewick Farm, Willow Bend Wetland, and the town of Ledwich. Put three to five students in each role and seat them in a ring in that order. Hand the Tolvern Creek group 20 cards to start. Give the Rain Cloud group the remaining cards as a supply. Explain that cards only ever move to or from the creek, because the creek is what the class is tracking.

Step 2, round one, a wet week (8 min): Read the round aloud one line at a time and pause after each so the cards actually move. Rain Cloud gives 8 cards to the creek. Harewick Farm takes 5 cards from the creek for irrigation. Willow Bend Wetland takes 2 cards from the creek and holds them. The town of Ledwich takes 3 cards from the creek. Every student writes the creek's count on the handout before the next round begins.

Step 3, round two, a dry week (8 min): Rain Cloud gives 0 cards. Harewick Farm takes 5 cards. Willow Bend Wetland gives 1 card back to the creek. The town of Ledwich takes 3 cards. Students record the new count.

Step 4, round three, the farm switches to drip lines (8 min): Rain Cloud gives 4 cards. Harewick Farm takes only 2 cards this time. Willow Bend Wetland gives 1 card back. The town of Ledwich takes 3 cards. Students record the final count. The activity ends here, after the third round.

Step 5, handout questions (10 min): Students finish the handout, working items 1 through 5 from the counts they recorded and writing their answers to items 6 through 8.

Step 6, debrief (6 min): Ask the Tolvern Creek group to hold up the cards they have left and say the number aloud. Then ask the whole class the closing question: round three had half the rain of round one, so why did the creek end the round with the same number of cards it started that round with? Take two answers before confirming that the farm took three fewer cards and the wetland handed one back.

The Tolvern Creek Water Budget: A Gallon-Card Role-Play — Grade 5 Science
Name: ____________________________ Date: ______________

Student Handout

Every card stands for 1,000 gallons. Tolvern Creek starts with 20 cards.

Round Rain gives Farm takes Wetland Town takes
1 8 cards 5 cards takes 2 cards 3 cards
2 0 cards 5 cards gives back 1 card 3 cards
3 4 cards 2 cards gives back 1 card 3 cards
  1. The creek starts with 20 cards. In round 1 it gains 8 cards, then loses 5, then loses 2, then loses 3. How many cards does the creek hold at the end of round 1?
  2. Each card stands for 1,000 gallons. The creek holds 18 cards at the end of round 1. How many gallons is that?
  3. The creek holds 18 cards at the start of round 2. It gains 0 cards, loses 5, gains 1 back, and loses 3. How many cards does it hold at the end of round 2?
  4. The creek held 18 cards before round 2 and 11 cards after it. How many cards did the creek lose during that round?
  5. The creek holds 11 cards at the start of round 3. It gains 4 cards, loses 2, gains 1 back, and loses 3. How many cards does it hold at the end of round 3?
  6. In round 2 the farm took 5 cards. In round 3 the farm used drip lines and took 2 cards. How many cards did the drip lines save?
  7. Round 3 had 4 rain cards, which is half of the 8 rain cards in round 1. The creek still ended round 3 with the same count it started that round with. Explain how that happened.
  8. The wetland held 2 cards in round 1 and gave 1 card back in each of the next two rounds. Name the two Earth systems the wetland connects when it does that, and explain in one sentence.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key
  1. Answer: 18 cards. Work in order from 20 cards: 20 + 8 = 28, then 28 - 5 = 23, then 23 - 2 = 21, then 21 - 3 = 18 cards.
  2. Answer: 18,000 gallons. Multiply the number of cards by the gallons each card stands for: 18 x 1,000 = 18,000 gallons.
  3. Answer: 11 cards. Work in order from 18 cards: 18 + 0 = 18, then 18 - 5 = 13, then 13 + 1 = 14, then 14 - 3 = 11 cards.
  4. Answer: 7 cards. Subtract the end count from the start count: 18 - 11 = 7 cards lost during round 2.
  5. Answer: 11 cards. Work in order from 11 cards: 11 + 4 = 15, then 15 - 2 = 13, then 13 + 1 = 14, then 14 - 3 = 11 cards.
  6. Answer: 3 cards. Subtract the drip-line amount from the earlier amount: 5 - 2 = 3 cards saved, which is 3,000 gallons.
  7. Answer: The farm took only 2 cards instead of 5, and the wetland gave 1 card back, so the 4 rain cards plus the 1 returned card exactly replaced the 5 cards the farm and the town took (4 + 1 = 2 + 3). Accept any answer that names the smaller farm withdrawal, and give full credit when the wetland return is named as well.
  8. Answer: The hydrosphere and the geosphere. Water from the creek soaks into the wetland soil, waits there, and seeps back out later, so the wetland moves water between the creek and the ground. Accept an answer naming the hydrosphere and the biosphere when the student explains the role of wetland plants in holding the water.

Differentiation

Support

Give these students a handout with a running-total column already drawn, one row for each move in each round, so they add or subtract one number at a time rather than tracking four moves in their heads. Seat them in the Tolvern Creek group for at least one round so they physically count the cards.

Extension

Ask these students to write a fourth round in which the creek must end with at least 14 cards, choosing their own rain, farm, wetland, and town numbers within the range of the first three rounds. They should show the running total and explain which single change did the most to raise the count.

ELL supports

Post a picture beside each role sign: a cloud, a winding line of water, a row of crops, a patch of reeds, and a cluster of houses. Pre-teach takes and gives back by demonstrating both with two cards before round one, and allow items 7 and 8 to be answered with a labeled drawing plus a short phrase.

Extensions

Have students trace the nearest creek or river to their school on a printed map the teacher supplies, mark every farm, park, or neighborhood the water passes, and write which of those places would take cards and which would give them back.