Project Grade 8 Social Studies & Civics
Rebuild or Buy Out? A Floodplain Plan for Grantly
A five-session grade 8 project in which students use land cover data and a fixed grant to build a flood plan for 18 homes and defend it to a village board panel.
Objectives
- Students will explain how land cover change in a watershed altered flooding downstream.
- Students will build a flood plan for 18 homes that stays within a fixed grant amount.
- Students will defend a recommendation to a board panel using evidence from maps and costs.
Vocabulary
- Floodplain
- A floodplain is the flat land next to a river that the river spills onto when it floods. Floodplains are natural storage areas that give floodwater a safe place to spread out.
- Detention basin
- A detention basin is a dug-out area that fills with stormwater during a storm and then slowly drains empty over hours or days. It holds the water back so streets and streams downstream do not flood.
- Impervious surface
- An impervious surface is any hard surface, like a road, roof, or parking lot, that rain cannot soak through. The more impervious surface a town has, the more stormwater rushes off it.
- 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.
Also: buyout, elevation
Teacher overview
The driving question for this project is which homes a village should protect, which it should raise, and which it should buy and remove after repeated flooding. Students work with a fictional village, a fixed grant that cannot cover every option, and a land cover table that shows what changed upstream over fifty years. The project mirrors the choice real communities face after a damaging flood, when state and federal money arrives with both a spending deadline and a limit on the total. The final deliverable is a three-page recommendation memo with an annotated map, presented to a panel acting as the village board. The misconception to address in the first session is the assumption that flooding got worse because it rains more; in this watershed the rainfall pattern is unchanged, while the share of the land covered by roofs and pavement rose sharply.
Project Brief
Grantly is a fictional village on Tenmile Creek. Water has entered the same 18 homes three times in the past twelve years. The state has awarded the village a flood grant of $2,400,000, which must be spent within two years. Your team advises the village board.
The table below describes the land cover in the watershed above the village. The rain gauge record shows no change in yearly rainfall over the same period.
| Land cover in the Tenmile Creek watershed | 1970 | Today |
|---|---|---|
| Woods and fields | 82 percent | 46 percent |
| Streets, roofs, and parking lots | 6 percent | 34 percent |
| Lawns and parks | 12 percent | 20 percent |
The village engineer has priced five measures. You may combine them in any way.
| Measure | Cost | What it does |
|---|---|---|
| Buy a home and clear the lot | $180,000 for each home | Removes that home from the floodplain for good; the lot becomes open space |
| Raise a home on a new foundation | $95,000 for each home | Lifts the living space above the flood level; the yard still floods |
| Build a levee along the east bank | $1,600,000 | Protects 11 of the 18 homes; the village must inspect and maintain it |
| Build a detention basin upstream | $700,000 | Holds runoff during storms and protects 6 homes on higher ground |
| Replace two culverts on Mill Road | $260,000 | Clears street flooding on the main route to the school; protects no home directly |
On the village map, Tenmile Creek runs north to south through Grantly. Eleven of the 18 homes sit on the low east bank, behind the line where the levee would go. Six sit on slightly higher ground on the west bank, and the basin would protect them. The last home sits alone at the Mill Road bend, outside both areas. No home is covered by both the levee and the basin.
Your plan must meet four conditions:
- Stay within the grant of $2,400,000.
- Name a measure for each of the 18 homes, or explain why a home is left out.
- Say who maintains anything built, and who pays for that upkeep after the grant is spent.
- Use the land cover table to explain why the flooding changed.
Your team turns in three items: a memo of three pages or less with a clear recommendation, an annotated village map showing which measure applies where, and a five-minute presentation to the board panel.
Milestones
- Session 1, reading the watershed. Compare the 1970 and current land cover figures. Write a paragraph explaining what changed and how that change affects the creek during a storm. Mark the floodplain and the 18 homes on the blank village map. Output: the paragraph and the marked map.
- Session 2, screening the options. Price at least three different combinations of measures. Record each combination's total cost and the number of homes it covers in a budget table. Output: a budget table with three costed combinations, each within the grant.
- Session 3, drafting. Choose one combination and draft the memo. State the recommendation in the first paragraph, then give two reasons with evidence from the tables. Add the upkeep answer. Output: a complete first draft and a labeled map.
- Session 4, review and revision. Trade drafts with another team. Check the other team's plan against the four conditions and mark any condition it misses. Revise your own draft using the notes you receive. Output: a completed review sheet for another team and a revised memo.
- Session 5, the board hearing. Present for five minutes to the panel, then answer two questions from board members. Output: the presentation and the final packet.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Rubric
| Criterion | Advanced | Proficient | Developing | Emerging |
|---|---|---|---|---|
| Use of maps and data | Explains the land cover change precisely and connects it to storm runoff and to specific homes on the map | Explains the land cover change and connects it to flooding in general terms | Notes that land cover changed but does not connect it to flooding | Does not use the land cover table |
| Meeting the constraints | Plan is within the grant, covers all 18 homes, and states upkeep and who pays for it | Plan is within the grant and covers all 18 homes; upkeep is named briefly | Plan is within the grant but leaves homes unaddressed, or omits upkeep | Plan exceeds the grant or does not total its costs |
| Argument and evidence | States a clear recommendation and supports it with two pieces of evidence, and answers the strongest objection to the plan | States a clear recommendation supported by two pieces of evidence | States a recommendation with one piece of evidence | States a preference with no evidence |
| Presentation to the board | Presents within time, uses the map as evidence, and answers both board questions with specifics | Presents within time and answers board questions | Presents but runs long or short, or answers questions vaguely | Does not present a complete plan |
Differentiation
Support
Give these teams a partly completed budget table for the fictional grant, with one combination already priced, so they begin by checking arithmetic rather than generating options. Provide the memo as a four-paragraph frame with a stated purpose for each paragraph, and assign the map annotation as the team's primary output.
Extension
Ask teams to add a fifth condition of their own choosing, such as protecting the route to the school or keeping any single household's share of upkeep below a stated amount, and to show how their plan changes once that condition applies.
ELL supports
Pre-teach "floodplain," "buyout," "elevation," "detention basin," and "upkeep" with a labeled cross-section of a creek, a home at ground level, and a raised home. Provide the presentation as a five-slide template with one sentence starter for each slide, and allow teams to rehearse with a partner before the panel session.
Extensions
Students can look up whether their own community has a mapped floodplain and how many properties sit inside it, then compare the local pattern with the fictional village in this project. A second option is to invite a county emergency manager or floodplain administrator to hear the final presentations and respond to two plans.