From Floyd to Irene: heavy rainfall events and associated flooding in New Jersey

In September 1999, Hurricane Floyd produced extremely heavy rain from the Carolinas to New England. In New Jersey, at least one station in 12 of the state's 21 counties reported at least 8 inches (20 cm) of storm total rainfall. Massive flooding occurred along several major waterways in the state, including the Raritan River, which crested at a record 14.1 feet (4.3 meters) above flood stage at Bound Brook, NJ.

In August 2011, Hurricane Irene also skimmed the Atlantic coast, making its eighth overall landfall as a tropical storm near Brigantine, NJ. While the wind and storm surge impacts in New Jersey were less severe than forecast, rainfall exceeded 7 inches (18 cm) at one or more stations in every county. Significant flooding, especially in the Passaic and Raritan basins, washed out several major roads, bridges, and railways across the state.

While Floyd and Irene's deluges led to the most memorable floods in New Jersey's recent past, the 1999-2011 period was also riddled with heavy rain and flooding events of both tropical and extratropical origin (e.g. Delaware River basin in 2004, 2005 and 2006; statewide in 2007 and 2010). Because New Jersey is the most densely populated state and a key transportation hub, heavy rainfall events critically impact public safety and infrastructure. Our presentation will compare and contrast hydrologic aspects of the recent heavy precipitation events, examine their impacts, and provide insights that may contribute to better forecasting, preparation, and response.