Classroom activity Grade 7 Science

Keep Pinehaven Flowing: A Water Tower and Demand Simulation

A grade 7 role-play where students act as a town's water tower, pumps, and neighborhoods to keep the tank from running dry across a simulated 24-hour demand cycle.

Grade: Grade 7
Subject: Science
Material: Classroom activity
Time: 40 min
Prep: Low prep
Materials: About 60 counters, cubes, or paper tokens, A container to serve as the tank, 8 demand cards, one for each three-hour block, Role cards for tank, pumps, and neighborhoods

Standards

MS-ETS1-4 NGSS

Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved.

How this material aligns: Students run a working model of the tank-and-pump system that generates tank-level data each block, then test operator responses and re-run under heavier demand to recommend whether a larger tank, faster pump, or conservation rule best keeps the tank above its minimum.

All materials for MS-ETS1-4 →

Download Word file

This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-23.

Objectives

Students will model how a water tower stores water to meet changing demand.
Students will explain why pumps and storage must be balanced to keep pressure.

Vocabulary

Distribution system: A distribution system is the network of pipes, pumps, valves, and storage tanks that carries treated water from a treatment plant to homes, schools, and businesses. Most of it is buried underground beneath streets.
Water tower: A water tower is a big tank raised high above town that stores drinking water. Its height is what pushes water through the pipes, keeping the pressure steady even when the power goes out.

Also: demand, storage, pressure

Teacher overview

This is a whole-class role-play simulation for 12 to 30 students that turns the room into the fictional town of Pinehaven's water system. One student keeps the elevated tank, which holds tokens that stand for stored water; two students are pumps that add tokens at a steady rate; and the rest are neighborhoods that draw tokens according to demand cards. The activity maps directly onto the concept: a water tower stores extra water during quiet hours so that when morning and evening demand spikes, the town can draw more water than the pumps alone could supply, all while keeping the tank above the level needed to hold pressure.

Activity Directions

Before class, set the tank container where everyone can see it and place 18 tokens in it as the starting level. Mark a "minimum line" at 10 tokens; if the tank ever drops below it, the town loses pressure. Utilities aim to stay well above the state minimum of 20 psi, which is the real-world version of never letting the tank run too low.
Assign roles: two students are pumps, one student is the tank keeper who counts tokens aloud after each block, and the rest split into three or four neighborhood groups.
Explain the round structure. Each round is one three-hour block of the day. There are eight blocks, so the simulation covers a full 24 hours.
Each block, the pumps first add a fixed 6 tokens total to the tank (their steady supply). Then the neighborhoods draw the number of tokens printed on that block's demand card. Each card gives the whole town's draw, so split it among the neighborhood groups as evenly as possible.
Use these eight demand cards, in order: 12-3 a.m. draws 3 tokens; 3-6 a.m. draws 3; 6-9 a.m. (morning peak) draws 12; 9 a.m.-noon draws 8; noon-3 p.m. draws 6; 3-6 p.m. draws 8; 6-9 p.m. (evening peak) draws 12; 9 p.m.-midnight draws 4.
After each block, the tank keeper counts the tokens remaining and announces whether the tank is above or below the 10-token minimum line.
If the tank falls below the minimum line, pause and ask the class what a real operator could do: start a backup pump (add 4 tokens now), ask neighborhoods to conserve (reduce the next draw by 2), or both. Apply the class's choice and continue.
End the simulation after all eight blocks. Record the tank's final level and how many blocks, if any, dropped below the minimum line.

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

Answer Key

Debrief question: Why did the tank rise overnight and fall during the morning and evening blocks? Answer: Overnight the pumps added 6 tokens while neighborhoods drew only 3, so storage grew; during the morning and evening peaks the draw of 12 was larger than the 6 the pumps supplied, so the tank fell to cover the gap.
Debrief question: Why does the town need the tower at all if the pumps run all day? Answer: The pumps supply a steady amount, but demand is uneven, so the stored water in the tower covers the peaks when demand rises above what the pumps can deliver on their own.
Debrief question: What did starting a backup pump or asking neighborhoods to conserve do to the tank level? Answer: Both actions kept the tank above the minimum line, one by adding supply and the other by lowering demand, which is how operators protect pressure during a shortage.

Differentiation

Support

Give the tank keeper a printed tracking sheet with a row for each block and columns for tokens added, tokens drawn, and tokens remaining, so counting stays organized. Pair a stronger counter with the tank keeper role.

Extension

Have students run the simulation a second time with a heat-wave demand set (every block draws 2 more tokens) and write a short recommendation on whether Pinehaven needs a larger tank, a faster pump, or a conservation rule.

ELL supports

Post picture cards for tank, pump, and neighborhood, and pair each demand card with a small icon showing high or low use. Let students announce tank levels by pointing to an above or below marker rather than speaking a full sentence.