The following text is from a letter published in 1884 by naturalist Amelia Hartwright to the Midland Gazette. In the letter, Hartwright responds to growing public concern about the annual flooding of the Grayleaf River.
It has become fashionable among the city newspapers to denounce the Grayleaf’s spring swelling as a catastrophe to be contained at any cost. I do not deny that the swollen currents undo roads, soak granaries, and test the nerves of every farmer living within sight of the levees; nor would I leave a breached embankment unmended merely to honor nature. Yet to count only the inundation’s injuries is to keep one side of the ledger. The same muddy torrents carry silt richer than any manure spread by hand, refresh the oxbow marshes where the black-crowned night-heron breeds, and replenish the groundwater that sees us through August’s drought. Engineers who promise a river obedient within higher walls count the acres spared in spring, but not what those acres would cease to receive. Protection of homes is prudence; imagining that the river can be deprived of its floodplain without depriving us in turn is not.
Which choice best states the main idea of the text?
For a central-idea question, identify the passage’s main concession and main claim, then choose the option that accurately combines the ideas receiving the most development. Pay close attention to scope: a passage that criticizes controlling a natural process “at any cost” does not necessarily reject every limited protective measure. Eliminate choices that isolate one example, make an unsupported comparison, or convert a qualified position into an absolute one.
Hints
Separate the concession from the main claim
Identify what Hartwright admits about the floods and what she argues readers have overlooked.
Follow the ledger metaphor
Consider what the “one side of the ledger” represents and what details Hartwright adds to the other side.
Check the scope of each choice
Be cautious of an option that turns criticism of an extreme approach into opposition to every protective measure or that focuses on only one consequence.
Step-by-step Explanation
Identify the opening position
Hartwright begins with the widespread view that the river’s flooding is a catastrophe that should be contained “at any cost.” She then concedes that the floods genuinely damage roads and granaries, so her claim is not that flooding is harmless.
Track the central contrast
The phrase “one side of the ledger” introduces the passage’s central contrast. Alongside the immediate damage, the floods deposit fertile silt, sustain marsh habitat, and replenish groundwater during the summer drought.
Determine the scope of the argument
Hartwright does not reject every protective measure: she supports mending embankments and calls protecting homes prudent. Her objection is to evaluating flood control without considering what the surrounding land would lose if it were separated from the river’s seasonal flooding.
Select the most complete statement
The best answer captures both the acknowledged losses and the lasting benefits without turning Hartwright’s qualified argument into a blanket rejection of flood-control measures. Thus, the main idea is that assessments of the flooding should account for its support of the surrounding land as well as its immediate damage.