Project Grade 10 Math

Hollowdale Farm Irrigation Water Budget Design Project

A grade 10 project where teams design a season's irrigation plan for a fictional 40-acre field, comparing flood and drip efficiency to fit a water and equipment budget.

Grade: Grade 10
Subject: Math
Material: Project
Time: 4 sessions, ~200 min total
Prep: Moderate prep
Materials: Grid paper, Rulers, Calculators, Teacher-provided irrigation price sheet

Standards

HSG-MG.A.3 Common Core Math

Apply geometric methods to solve design problems (e.g., designing an object or structure to satisfy physical constraints or minimize cost).

How this material aligns: In Milestone 3, teams design a field layout and irrigation method that satisfy a water budget and a cost limit, the design-under-physical-constraints work this standard requires.

All materials for HSG-MG.A.3 →

HSA-CED.A.3 Common Core Math

Represent constraints by equations or inequalities, and by systems of equations and/or inequalities, and interpret solutions as viable or non-viable options in a modeling context.

How this material aligns: Teams treat the 120 acre-foot budget and the equipment cost as constraints and judge each irrigation option as viable or non-viable, the constraint-interpretation this standard describes.

All materials for HSA-CED.A.3 →

HSN-Q.A.1 Common Core Math

Use units as a way to understand problems and to guide the solution of multi-step problems; choose and interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays.

How this material aligns: Milestone 1 carries units from acres and feet of applied water into acre-feet and gallons, the multi-step unit reasoning this standard names.

All materials for HSN-Q.A.1 →

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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 compute a crop's seasonal water demand in acre-feet and convert it to gallons.
Students will compare irrigation methods against a water budget and an equipment cost limit.

Vocabulary

Acre-foot: The amount of water it takes to cover one acre of land, about the size of a football field, one foot deep. Western states use acre-feet to measure large amounts of water.
Irrigation efficiency: The share of irrigation water that crops actually use compared with the amount taken from the river or well. Higher efficiency means less waste.
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.

Also: constraint

Teacher overview

The fictional Sablewood Irrigation District gives each farm a fixed water budget for the season, measured in acre-feet. Over four sessions, teams design an irrigation plan for a fictional 40-acre hay field that meets the crop's water need without going over budget. The driving question asks whether flood irrigation or drip irrigation can do the job within the water and money limits. Teams present a scaled field plan and a written proposal to a fictional district board.

Hollowdale Farm Irrigation Water Budget Design Project — Grade 10 Math

Name: ____________________________ Date: ______________

Project Brief

Driving question: How can we irrigate a 40-acre field for the season, meet the crop's water need, and stay within both a 120 acre-foot water budget and a $15,000 equipment budget?

Scenario: Hollowdale Farm (a fictional farm) grows hay on a rectangular 40-acre field. The Sablewood Irrigation District has granted the farm 120 acre-feet of water for the season. The crop needs 2.0 feet of water delivered to its roots over the season.

Constraints (all figures fictional, set for this project):

Water budget: 120 acre-feet for the season. The water actually withdrawn must not exceed this.
Crop need: 2.0 feet of water reaching the roots across the 40 acres.
Irrigation efficiency: flood irrigation delivers about 60 percent of withdrawn water to the roots; drip irrigation delivers about 90 percent.
Equipment budget: $15,000 for pipe, emitters, or gated pipe, priced from the teacher's sheet.
Useful conversions: 1 acre-foot = 325,851 gallons; 1 acre = 43,560 square feet.

Final deliverable: A scaled field plan on grid paper showing the field, the irrigation layout, and the water zones, plus a one-page written proposal to the Sablewood district board. The proposal must show the crop's net water need, the water withdrawn under the chosen method, and proof that both the water budget and the equipment budget are met.

Milestones

Session 1 (Compute the net water need): Teams find the crop's net water demand in acre-feet by multiplying the field area by the depth of water needed at the roots. They then convert that demand to gallons. Output: a calculation sheet showing net demand in acre-feet and gallons.
Session 2 (Compare methods against the budget): Teams find the water withdrawn under flood irrigation and under drip irrigation by dividing the net demand by each method's efficiency. They compare each result to the 120 acre-foot budget and mark each method as viable or over budget. Output: a comparison table with both withdrawals and a viability note.
Session 3 (Design the field and equipment plan): Teams choose the viable method and draw a scaled field layout on grid paper with irrigation zones. They price the equipment from the teacher's sheet and adjust the design to stay at or under $15,000. Output: a scaled site plan with an itemized cost list at or under budget.
Session 4 (Write and present the proposal): Teams write the one-page proposal and present it to the class acting as the Sablewood district board. Output: a completed written proposal and a short team presentation.

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

Rubric

Criterion	Emerging	Developing	Proficient	Advanced
Net water demand	Demand is missing or computed with the wrong operation	Demand is set up correctly but has a unit or arithmetic error	Net demand is correct in acre-feet and converted to gallons	Net demand is correct, clearly shown in both units, with each step labeled
Water-budget compliance	Chosen method exceeds 120 acre-feet or budget is not checked	Withdrawal is computed but the comparison to the budget is unclear	Withdrawal is correct and shown to be within the 120 acre-foot budget	Withdrawal is within budget and the team explains the efficiency choice that made it fit
Equipment cost limit	Cost exceeds $15,000 or is not itemized	Cost is close to $15,000 but not fully itemized	Cost is at or under $15,000 with an itemized list	Cost is at or under $15,000, itemized, with a noted tradeoff the team made to stay within it
Proposal and presentation	Proposal is incomplete or hard to follow	Proposal covers the design but omits some reasoning	Proposal clearly shows the water need, withdrawal, and both budgets are met	Proposal is clear, complete, and anticipates a likely question from the district board

Differentiation

Support

Give teams the net water demand already computed (40 acres times 2.0 feet) so they can begin at the method comparison in Session 2. Provide a simplified price sheet with fewer equipment choices, and a filled-in example of dividing a demand by an efficiency.

Extension

Ask teams to find the exact crop water depth, in feet, at which flood irrigation would just barely fit inside the 120 acre-foot budget, and to explain why a leakier method forces a farm to withdraw more water for the same crop. Have them propose one change that would let flood irrigation qualify.

ELL supports

Provide a labeled diagram contrasting flood and drip irrigation, showing water reaching the roots versus water lost, so the efficiency percentages are visual. Allow the written proposal to pair short sentences with labeled sketches, and pre-teach "efficiency," "budget," and "withdrawal."

Extensions

Teams can research a real crop grown in their region and its typical seasonal water need, then repeat the Session 1 and Session 2 math with those figures on the same 40-acre field. A short comparison can note whether that crop would fit the fictional 120 acre-foot budget under drip irrigation, connecting the project to local growing conditions.