Suburban development silted a Virginia lake fifteen times faster than farming had.

Evidence

Because the lake was built in 1915 as a water-supply reservoir, the study could compare the rate of sedimentation over a span of more than 40 years, and the results showed a dramatic intensification of the problem in the 1940s and 1950s. From 1915 to 1938, when the surrounding area was mostly farmland, the deposition of silt from erosion caused the lake to shrink by just four-tenths of an acre. But in the period after 1938, when nearly 70 percent of the lake’s watershed was transformed into suburban neighborhoods, the lake shrank by six acres. — Adam Rome, The Bulldozer in the Countryside, 817

Categorization

• CANDY: A clean factual contrast: 0.4 acre of silt in 23 farm years versus 6 acres in the suburban decades — a fifteen-fold difference perfect for a conversation or a lecture hook.
• XREF: connects to: Bulldozed suburban lawns shed rainwater almost like concrete. — Adam Rome, The Bulldozer in the Countryside:…, 810