Simulate a constrained school water plan

Which water-system design meets demand, reserve and cost constraints under uncertain supply?

Submit: Three or more scenario tables, constraint matrix, sensitivity test and design recommendation.

Related lesson: Senior Research Project

This is a teacher-led extension beyond the short lesson. The task supplies a performance opportunity; completion alone does not certify mastery, full NGSS coverage or state alignment.

Build the idea

Engineering simulations compare proposed designs under interacting criteria and constraints. Storage, inflow, demand and conservation affect one another over time. A design that works under an average input can fail during a dry interval. A simplified model should be tested against limiting cases before its results guide a decision.

Evidence and model inputs

Use the embedded water-design simulator for a hypothetical school. Monthly incoming water units: 80,70,60,40,30,20,20,30,40,60,70,80. Baseline demand=60/month; tank capacity=150; initial storage=capacity/2. Conservation reduces demand by a chosen percentage. Each month add supply up to capacity, record overflow, then deliver available demand. Cost=20×capacity + 100×conservation percentage points. Requirements: zero shortfall, final reserve≥30 and cost≤$6,000. Costs and supply units are invented, not procurement estimates.

Keep actual observations, published findings and invented model cases labeled separately. If a source or required equipment is unavailable, pause that part with a teacher; do not invent results.

Materials and preparation

Browser with embedded water-design simulator; paper or spreadsheet for comparison.

Grade-level scope

Original simplified engineering model; not a plumbing design, drinking-water recommendation or real budget.

Do the work

1. Run the baseline and inspect month-by-month stock, overflow and shortfall.
2. Create at least three designs varying tank capacity and conservation; calculate cost and classify every constraint.
3. Explain why increasing storage cannot create annual supply and why reducing demand can interact with tank size.
4. Test a 20% supply reduction and compare robustness of the qualifying designs.
5. Recommend a design using simulation evidence, identify assumptions and propose field measurements plus stakeholder review before real implementation.

Run and compare scenarios

Hypothetical educational model. Read the equation, event order and assumptions above. Export each scenario before changing inputs; nothing is sent to a server.

Learner worksheet

Write on paper or type here and print. Entries stay in this page’s memory and are lost when you leave or reload; they are not saved or submitted.

Check your reasoning

1. Can an arbitrarily large tank create water?
2. What does overflow indicate?
3. Why keep the monthly table?
4. Does passing the baseline prove real-world performance?

Teacher review guide

Review the actual deliverable and discuss the reasoning. For each criterion, use 0 when evidence is absent or fundamentally incorrect, 1 when partly supported with a material error or omission, and 2 when accurate, supported and complete for the stated task. Maximum 8 points is a task score, not a proficiency certification. Give feedback and allow revision.

1. Uses a computational representation of interacting system parts.
2. Compares multiple designs against every constraint.
3. Tests uncertainty and verifies model behavior.
4. Supports a recommendation with limitations and validation plans.

Sources and standard reference

• Official NGSS HS-ETS1-4 performance expectation — inspect the practice, core idea, crosscutting concept and assessment boundary.

Instructional text and hypothetical cases are original. Linked source readings supply published evidence where specified. Teachers should judge fit with their course and state requirements.