Severe floods occurred in Puerto Rico twice in 1985. During May 15-19, 1985, as much as 25 in. of rainfall produced significant floods along north and north-central basins in the island. A nearly stationary tropical depression affected Puerto Rico during October 5-8, 1985, resulting in 24-hr precipitation totals of as much as 23 in. and severe floods along the south-central coastal areas. During the May 17-18, 1985 event, the areas most seriously affected by flooding were along the north coast. These included the lower reaches of the Rio Grande de Manati and the Rio Grande de Arecibo. Significant flooding also occurred at Utuado and Jayuya. The recurrence interval of most of the flood peaks was generally < 25 yr. The floods of October 6-7, 1985, affected mostly rural areas in southern Puerto Rico, but caused significant loss of life and widespread property damages. Landslides near Ponce, the collapse of a bridge at Rio Coamo, and the destruction of homes near Ponce resulted in about 170 fatalities and > 125 million dollars in damages. Flooding was also severe at Barceloneta on the north coast. Recurrence intervals = or > 100 yr were estimated for peak discharges at several index stations. (Author 's abstract)