The March issue of Harper's includes an article by Elizabeth Royte called "The Hidden Rivers of Brooklyn," which begins with a discussion of the view from a parapet on the tower of Litchfield Villa, on the western edge of Prospect Park.
"I was barely able to make out -- over treetops and tall buildings -- a glint of Gowanus Bay, roughly two miles away. Edwin Litchfield ... would have had no trouble seeing the bay and much of his land holdings out of a second-floor window."
Thus, she has set up her themes, of development, Brooklyn's history, and water.
Two paragraphs later she introduces us to Eymund Diegel, a sort of hydrological Adrian Monk, and she follows him, carrying the reader along, as he tries to reconstruct the one-time flow of water over the area, as it would have run back before the water was corralled into pipes.
A few grafs further on, we're treated to this description, which is worth the price of the issue at a newsstand: Wandering along the presumed course of Vechte's Brook, Diegel repeatedly dropped to the ground to listen at manhole covers and drains. He blurted out contextual clues: that anomalously large tree hinted at a steady water source; a discharge pipe protruding from a school basement spoke to regular flooding. 'That's as good as a chalk line on a sidewalk,' Diegel said.