Worksheet Grade 11 Careers & CTE

Drennan Ridge Well Field: A Pumping and Hydraulics Worksheet

A grade 11 careers worksheet on operator hydraulics: students find well drawdown, pipe velocity, flow conversions, and tank fill time at a fictional well field.

Grade: Grade 11
Subject: Careers & CTE
Material: Worksheet
Time: 45 min
Prep: No prep
Materials: Calculator

Standards

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: Items 4 and 5 carry cubic feet per second, square feet, and gallons per minute through the continuity equation and a flow conversion, the consistent-unit reasoning this standard requires.

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 calculate well drawdown and pipe velocity using operator hydraulics formulas.
Students will convert between flow units and find the time to fill a cylindrical reservoir.

Vocabulary

Drawdown: Drawdown is how far the water level in a well drops when a pump pulls water out. The harder and longer you pump, the bigger the drawdown gets.
Flow rate: Flow rate measures how much water moves past a point in a certain amount of time, like gallons per minute through a garden hose. Bigger pipes and stronger pushes give bigger flow rates.

Also: continuity, cylindrical volume

Teacher overview

Groundwater operators live by a handful of hydraulics formulas, and this worksheet drills them in one connected setting. Students work through the fictional Drennan Ridge well field to find drawdown, pipe velocity, flow conversions, and tank fill time. The common misconception this worksheet corrects is using a pipe's diameter in place of its cross-sectional area when applying the continuity equation; area, not diameter, is what multiplies by velocity to give flow.

Drennan Ridge Well Field: A Pumping and Hydraulics Worksheet — Grade 11 Careers & CTE

Name: ____________________________ Date: ______________

Student Worksheet

The fictional Drennan Ridge well field supplies a small town. Use these facts for every problem: one MGD equals 694 gpm; one cubic foot per second equals 448.8 gpm; one cubic foot holds 7.48 gallons; a cylindrical tank's volume in cubic feet equals 0.785 × diameter² × depth; well drawdown equals the pumping water level minus the static water level; flow Q equals area × velocity.

The static water level in the well sits 60 feet below the ground surface. While the pump runs, the level drops to 145 feet below the surface. What is the drawdown, in feet?
The well pump delivers 900 gpm. Convert this flow to MGD, using one MGD equals 694 gpm. Round to the nearest hundredth.
The transmission main is a pipe 1.5 feet in diameter. Find its cross-sectional area in square feet, using area equals 0.785 × diameter².
The flow in that main is 4.0 cfs. Using Q equals area × velocity and your area from item 3, find the water velocity in the pipe, in feet per second. Round to the nearest hundredth.
Convert the 4.0 cfs flow to gallons per minute, using one cubic foot per second equals 448.8 gpm.
At 900 gpm, how many gallons does the well deliver during a 6-hour pumping run?
A storage reservoir at the well field is a cylinder 30 feet in diameter and 20 feet deep. Find its volume in gallons.
Starting from empty, how long will it take to fill the reservoir in item 7 at 900 gpm? Give your answer in hours.
Explain why drawdown is a number a pump operator watches closely during a long pumping run.

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

Answer Key

Answer: 85 ft. Drawdown = 145 ft − 60 ft = 85 ft.
Answer: 1.30 MGD. 900 gpm ÷ 694 gpm per MGD = 1.297, which rounds to about 1.30 MGD.
Answer: 1.77 sq ft. Area = 0.785 × (1.5 ft)² = 0.785 × 2.25 = 1.77 sq ft.
Answer: 2.26 ft/s. Velocity = Q ÷ area = 4.0 cfs ÷ 1.77 sq ft = 2.26 ft/s.
Answer: 1,795.2 gpm. 4.0 cfs × 448.8 gpm per cfs = 1,795.2 gpm.
Answer: 324,000 gal. 900 gpm × 60 minutes × 6 hours = 324,000 gallons.
Answer: 105,692.4 gal. Volume = 0.785 × (30 ft)² × 20 ft = 14,130 cu ft; 14,130 × 7.48 gal per cu ft = 105,692.4 gallons.
Answer: About 2.0 hours. 105,692.4 gallons ÷ 900 gpm = 117.4 minutes; 117.4 ÷ 60 = 1.96, or about 2.0 hours.
Answer: A rising drawdown means the water level in the well is dropping faster than the aquifer can refill it, which can pull the level below the pump, damage the pump, or signal that the well is being pumped harder than it can sustain.

Differentiation

Support

Provide item 3's area already computed (1.77 square feet) so students can begin the velocity calculation in item 4 without stalling, and give a printed card listing all six facts from the worksheet header.

Extension

Ask students to find, for the same reservoir in item 7, how the fill time would change if the pump rate dropped by one third, and to explain in a sentence why a lower flow means a longer fill time.

ELL supports

Pre-teach "drawdown," "continuity," "flow rate," and "cylindrical volume" with simple definitions and a labeled cross-section of a well and a pipe. Allow students to show item 4 with the diagram and numbers rather than a full written sentence.