The Council Packet: Protect the Ecosystem or Pay to Replace It?

Investigation question: For three ecosystem services a fictional California town depends on, which mix of protecting, restoring or replacing best keeps the services and the biodiversity behind them, within a 30-year budget and with fair treatment of the people affected?

Scientific purpose

Groups act as the town council of Marisol Bay, a fictional coastal California town facing three decisions at once: whether to protect the forest that keeps its drinking water clean or build a filtration plant, whether to restore dunes and marsh or build a seawall, and whether to keep an oak woodland that feeds wild bees for valley farms or clear it for warehouses and rent more hives. Students calculate 30-year costs and cost per home, find packages that fit the budget, score every option on weighted criteria, hear stakeholder concerns, and defend a recommendation in a council hearing.

Why this helps students with this chapter

The PE asks students to evaluate competing solutions, which cannot be done with a single right answer. The packet gives three services with three different kinds of trade-off: one where protecting nature is far cheaper (water), one where the cheaper natural option is slower to work (flooding), and one where the human-made replacement brings money and jobs to the town (pollination). Calculating, scoring and arguing in front of the class shows students that science supplies the predictions and the costs, while people's values set the weights.

Standards connections

MS-LS2-5 (assesses, evaluating competing design solutions for maintaining ecosystem services and biodiversity against scientific, economic and social constraints): Students compare protect, restore and replace options for water purification, flood protection and pollination, weigh scientific evidence (how each option maintains the service and the habitat), economic constraints (30-year costs, the budget, who pays) and social constraints (housing, jobs, stakeholder concerns), and write an evidence-based recommendation. This is direct evidence toward the PE as written.

MS-ETS1-2 (assesses, a systematic weighted decision matrix): Each group sets criterion weights, scores all seven options on the same scale and computes weighted totals, then uses the totals and the budget to justify its choices.

MS-ETS1-1 (practice, stating constraints and turning concerns into testable criteria): Students identify the budget and stakeholder limits as constraints and, in q8, turn the goal of keeping a service into a measurable monitoring criterion with a trigger for action. Most criteria are supplied, so this is practice.

MS-ESS3-3 (supports, monitoring a human impact on an ecosystem service): MS-ESS3-3 is a Grade 6 performance expectation in the California integrated sequence; it is background here. The q8 monitoring plan revisits the Grade 6 idea of monitoring and minimizing a human impact.

Roles (rotate each session)

• Water engineer: Leads Decision 1: computes the costs for 1A and 1B, explains how the forest cleans the water, and reads the water district engineer's and housing advocate's statements.
• Coastal scientist: Leads Decision 2: computes the costs and cost per home for 2A, 2B and 2C, and reads the homeowner's and biologist's statements.
• Farm advisor: Leads Decision 3: computes the costs for 3A and 3B, tracks who pays and who gains, and reads the farmer's and company's statements.
• Budget chair: Checks every calculation, lists the packages that fit the budget, runs the decision matrix, keeps time and presents at the hearing.

Materials

Estimated cost: 2 to 4 per class (estimate) (an estimate; Printing only; calculators, sticky notes and the timer are classroom stock.)

Safety

• Paper and calculators only; no physical hazards.
• Marisol Bay, its people and its numbers are fictional. If students connect the lab to a real local decision, keep the discussion respectful of people who disagree and check facts before stating them.

Teacher preparation and setup

1. Solve the cost table and the budget packages yourself using the answer key so you can spot slips quickly; the most common error is multiplying a yearly cost by 3 instead of 30.
2. Decide how to run the hearing: each group presents its package in two minutes, or each of the four roles speaks for 30 seconds on its decision.
3. Draw a board table with the seven options down the side and space for each group's choice, so the class can see where groups agreed and disagreed.
4. If your community is debating a real development, dune or watershed decision, decide in advance whether to mention it, and keep the lab's numbers clearly fictional.

Investigation design

Student procedure

1. Session 1. Read the packet introduction, the option sheet and the stakeholder statements aloud; each role reads the statements for its decision.
2. Calculate the 30-year total for every option in the cost table (q1). Each role computes its own decision, and the Budget chair checks all seven.
3. Answer q2 (cost per home protected) and q3 (the replacement cost of the forest's water-cleaning service).
4. List the packages of one option per decision that fit the town's $80 million budget (q4).
5. As a group, choose a weight from 1 to 3 for each of the four criteria and write the weights in the matrix headings before scoring anything. Then score every option from 1 to 3 on each criterion and compute the weighted totals.
6. Decide one option for each decision; you may propose a hybrid if you give its cost and show it fits the budget. Write the group's recommendation in the claim-evidence-reasoning box.
7. Session 2. Council hearing: each group presents its package, its strongest piece of evidence and one stakeholder concern it answers, in two minutes. The class records every group's choices on the board and votes on each decision with sticky notes.
8. Answer q5-q10 individually, in class or for homework.

Expected observations

• Every group should find that 1A cannot fit the $80 million budget (it costs $135 million by itself) and that every package containing 1B fits, so every valid package uses 1B unless a group proposes a costed hybrid.
• Decision 2 splits groups: 2B is cheaper ($25.5 million, about $72,857 per home, versus $40 million, about $114,286 per home, for 2A) and adds habitat, but 2A protects homes sooner. Several groups propose hybrids. Few choose 2C once they see $54 million of expected damage falling on residents.
• Decision 3 is the most divided: groups that weight jobs, taxes or reliability heavily pick 3A; groups that weight biodiversity, the farmers' costs or long-term risk pick 3B.
• Changing the weights changes the winner in Decisions 2 and 3 but rarely in Decision 1, which shows students where the evidence decides and where values do.

Likely difficulties

• Multiplying a yearly cost by 3 or 10 instead of 30, or misplacing the decimal (0.6 x 30 = 18, not 1.8).
• Charging the farmers' hive rent (3A) or the residents' flood damage (2C) to the town budget, or treating 2C as free.
• Forgetting 2B's one-time $1.5 million of expected damage while plants establish.
• Choosing weights after scoring to make a favorite option win. Require weights in the headings before any scores.
• Giving every option the same scores, which makes the matrix useless; ask for at least one 1 and one 3 in every column.

Structured debrief

1. Show the board table of every group's choices. Decision 1 is settled by the budget: 1A alone ($135 million) breaks it, so every package that fits uses 1B unless a group costs out a hybrid; tell students this is the same logic New York City used, with numbers a hundred times larger.
2. Spend the most time where groups split. On Decision 2, ask the 2A groups what they weighted most (usually reliability now, for the Lowlands homeowner) and the 2B groups (cost and habitat). Collect the hybrid ideas from q7; point out that real coastal towns often combine restored dunes or marsh with a structure, like the levees behind the restored South Bay marshes.
3. On Decision 3, show the q5 numbers: under 3A the town gains about $12 million in taxes while farmers pay $9 million in rent and the wild bees decline; under 3B the town spends $3.9 million and keeps the woodland. Make the point that the replacement option is not always the expensive one, and that an honest analysis says so.
4. Close on q9: the class used the same evidence and still disagreed, because groups chose different weights. That is not a failure of science; it is the point where values and democratic decisions take over, which is why the evidence must be clear and the weights stated openly.

Recording sheet: what students fill in

Lab 3 council packet: Marisol Bay decides

Marisol Bay is a fictional coastal California town of 38,000 people, and every number in this packet is a teaching dataset; real costs depend on place and year. The town gets three ecosystem services without paying for them. A forest of 2,500 acres above Alder Creek reservoir keeps the drinking water clear, so the town only disinfects it. Dunes and a salt marsh at Shell Point shield 350 homes in the Lowlands neighborhood from storm waves, but a parking lot and foot traffic have damaged them. An oak woodland of 1,200 acres in Arroyo Valley houses wild bees that help pollinate 4,000 acres of almond and apple orchards. Three proposals now threaten or depend on these ecosystems, and the council must choose a 30-year plan.

Budget constraint: the town may spend at most $80 million over 30 years on these three decisions combined. Costs paid by town water customers (1A, 1B) come through the town's water bills and count toward the budget. Costs paid by farmers, homeowners or insurers do not come out of the town budget, but the council must still weigh them. 30-year total = up-front cost + (yearly cost x 30) + any other one-time cost.

Analysis questions: answer key

Individual evidence of learning

Each student submits the completed cost table, answers to q1-q4, the group's matrix and recommendation, and individual answers to q5-q10. The recommendation (cer) with q5, q6 and q7 is the main evidence for MS-LS2-5; the matrix is the evidence for MS-ETS1-2; q8 shows a measurable monitoring criterion; q9 shows understanding that values, not only data, decide.

Assessment criteria

Accessibility adaptations

• Provide a version of the cost table with the setup printed (up-front + yearly x 30 + other = ___) and a multiplication strip for x 30.
• Let each role complete only its own decision's calculations first, then teach them to the group; the Budget chair role suits a student who likes checking.
• Read the stakeholder statements aloud and offer picture icons for each speaker; allow a spoken or recorded recommendation in place of the written one.
• Give sentence frames: 'We chose ___ over ___ because it costs ___ less over 30 years and ___' and 'This answers the ___'s concern by ___.'

Low-cost alternative

The lab needs only printing. If printing is limited, project the option sheet and statements and have groups copy only the cost table and the matrix into notebooks; the hearing can become a gallery walk of posted recommendations.

Model limitations

This lab has not been tested with a class by the authors. Marisol Bay, its people and every number are invented teaching values, built so each decision has a real kind of trade-off; they are not estimates for any real place. Real decisions use ranges instead of single numbers, treat money spent decades from now as worth less than money spent today, must follow laws and permit rules, may include grants, and take months of public hearings. Replacement-cost estimates are themselves disputed, as New York City's was. The 1-3 matrix compresses complex trade-offs into a few numbers, and the weights express values, not science.

Teacher notes

All numbers are fictional and labeled simulated. Check every group's cost table before the matrix: a single multiplication slip (3 instead of 30) will distort the whole decision. Grade the recommendation with the cer criteria; there is no single correct package, but every package must fit the budget and be argued with correct numbers. The sample matrix in the cer key used weights cost 2, reliability 3, biodiversity 2, fairness 2 and scores 1A 1-3-1-2, 1B 3-2-3-2, 2A 2-3-1-2, 2B 3-2-3-2, 2C 1-1-2-1, 3A 2-2-1-2, 3B 3-2-3-2, giving totals 17, 22, 19, 22, 11, 16 and 22. Different weights or scores are fine if applied consistently.