Critics of the new river dam praised it as a triumph of engineering, and in the narrow sense they were right: it stood, it held, it generated power on schedule. What the engineers' reports omitted, because their instruments were not built to detect it, was the slow disappearance of the floodplain's seasonal silt, on which three generations of farmers had unknowingly depended. The river no longer overflowed, so the fields no longer renewed themselves, and within a decade yields fell even as the turbines hummed flawlessly. The dam had not failed; it had simply succeeded at a goal too small to contain the problem it was meant to solve.