Reading passage Grade 12 English Language Arts
Monitoring Wells Below Basalt County: A Groundwater Data Passage
A grade 12 informational passage pairing a fictional county's monitoring-well data table with a narrative on aquifer depletion, requiring students to integrate both.
Objectives
- Students will identify the stated cause of a described environmental change from an informational passage.
- Students will integrate a numeric data table with narrative explanation to answer inferential questions.
- Students will connect a global statistic to a local policy decision described in the passage.
Vocabulary
- Aquifer
- An aquifer is an underground layer of rock, sand, or gravel that holds water in the tiny spaces between its grains. Wells reach down into aquifers to bring water up to the surface.
- Recharge
- Recharge is water soaking down through the ground to refill an aquifer, the way rain refills an underground sponge. Aquifers stay healthy only if recharge keeps up with pumping.
- Monitoring well
- A monitoring well is a well drilled specifically to check on groundwater, not to supply drinking water. Scientists use monitoring wells to measure how high the water table is and to test for pollution before it can spread.
- Baseflow
- Baseflow is the water that keeps a stream flowing even when it has not rained for a while. It comes from groundwater slowly seeping into the streambed.
Also: subsidence
Teacher overview
Groundwater decline is one of the slower, less visible water crises in the country, tracked mostly through a network of monitoring wells whose readings, read alone, look like nothing more than a column of numbers. This passage follows Basalt County, a fictional county used for this passage, and its hydrologist as she explains what a decade of falling well readings actually means, pairing a monitoring-well data table with the narrative context needed to interpret it, exactly the kind of mixed-format reading students will do with real agency and utility data after graduation.
Passage
Basalt County is a fictional county used for this passage, but the aquifer beneath it works the way real aquifers do across much of the country's farm belt. For decades, the aquifer supplied water to household wells, two small towns, and thousands of acres of irrigated farmland. For decades, it also seemed inexhaustible. Then, in 2015, the county's newly hired hydrologist, Priya Okafor, began publishing annual readings from a network of monitoring wells. The numbers told a story residents had not fully grasped from watching their own taps.
An aquifer is not an underground lake. It is a layer of saturated soil, sand, or fractured rock that holds water in the spaces between particles. Water enters an aquifer through recharge: rain and snowmelt soak slowly downward through the soil above it. Water leaves an aquifer through natural discharge into streams and through wells that pump it out for use. When withdrawals consistently outpace recharge, the water table, the upper surface of the saturated zone, drops. Every well drawing from that aquifer then has to reach deeper to find water.
Okafor's monitoring well, drilled in the county's most heavily irrigated district, recorded the water table at 40 feet below the ground surface in 2015. By 2018 it had dropped to 58 feet. By 2021 it reached 77 feet, and by 2024 it stood at 95 feet below the surface, a trend Okafor described in her most recent report as "not a single dry year, but a compounding deficit."
| Year | Water table depth (ft below ground surface) |
|---|---|
| 2015 | 40 |
| 2018 | 58 |
| 2021 | 77 |
| 2024 | 95 |
The consequences of a falling water table extend beyond the cost of drilling a deeper well. As the water table drops below a stream's bed, the stream loses its baseflow, the steady groundwater contribution that keeps it running between rain events. It can then begin to run dry in summer, even in years with normal rainfall. In some parts of the country, the ground itself has sunk, a phenomenon called subsidence, as drained soil compacts. Basalt County has not yet measured significant subsidence, but Okafor's report flags it as a risk if current pumping continues for another decade.
Worldwide, agriculture accounts for roughly 70 percent of freshwater withdrawals, far more than household or industrial use. Basalt County's own water-use records show a similar pattern: irrigation districts, not households, account for the overwhelming majority of water pumped from the county's aquifer each year. That pattern shaped the county board's response. Restricting household water use would have done little to slow the decline. Instead, the board voted in 2025 to cap new irrigation-well permits in the most heavily pumped district. It also required existing irrigation wells to install metering, so the county can track withdrawals as closely as it now tracks the water table itself.
Recovery, if it comes, will not be quick. Recharge through soil and rock is a slow process; rain falling at the surface can take years to reach a deep aquifer. A water table that fell over a decade of sustained overpumping is unlikely to rise back to its 2015 level within just a few years of reduced pumping, even under the new permit cap. Okafor's report describes the county's goal not as reversing the decline immediately but as "stopping the deficit from compounding further." That is a more modest target, but a more achievable one for a resource that recovers on its own slow schedule.
Questions
- According to the passage, what is the main reason Basalt County's groundwater levels have fallen over the past decade?
- Using the data table, by how many feet did the monitoring well's water level drop between 2015 and 2024?
- According to the passage, what happens to a stream when the water table beneath it drops too far?
- Based on the data table and the passage's explanation of recharge, why does the passage suggest the aquifer will take years to recover even after the county's new permit cap takes effect?
- The passage states that agriculture accounts for roughly 70 percent of freshwater withdrawals worldwide. How does this detail help explain why the county's board targeted irrigation permits specifically, rather than household water use?
- What two actions did Basalt County's board take in 2025 in response to the falling water levels described in the passage?
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: Withdrawals, mainly for irrigation, have consistently outpaced the aquifer's natural recharge, causing the water table to drop year after year.
- Answer: 55 feet. The water table was 40 feet below the surface in 2015 and 95 feet below the surface in 2024; 95 − 40 = 55 feet.
- Answer: The stream loses its baseflow, the steady groundwater contribution that keeps it flowing between rain events, and can begin running dry in summer even during years with normal rainfall.
- Answer: Because recharge is a slow process, with rain and snowmelt taking years to soak down and reach a deep aquifer, a water table that fell steadily from 40 to 95 feet over a decade of overpumping cannot be expected to rise back quickly once pumping slows, even with the new permit cap in place.
- Answer: Because agriculture uses far more water worldwide than households do, and Basalt County's own records show irrigation districts account for the overwhelming majority of water pumped locally, restricting irrigation wells addresses the actual source of the decline in a way that restricting household use would not.
- Answer: The board capped new irrigation-well permits in the most heavily pumped district and required existing irrigation wells to install metering to track withdrawals.
Differentiation
Support
Provide a simplified version of the data table with the 2015-to-2024 change already calculated (55 feet) printed beside it, and allow question 4 to be answered orally with a partner before students write their response.
Extension
Ask students to calculate the average yearly rate of decline shown in the data table (roughly 55 feet over 9 years, or about 6 feet per year) and use that rate to estimate how deep the well might reach by 2030 if the trend continued unchanged, then explain in one sentence why the new permit cap makes that estimate unlikely to hold.
ELL supports
Pre-teach "aquifer," "recharge," and "water table" with a labeled cross-section diagram showing rain soaking downward and a well drawing water upward. Allow questions 1, 3, and 6 to be answered with short phrases rather than full sentences.