Flash Flood — Middlesex, New Jersey

2005-07-17 to 2005-07-18 · near Southeast Portion, Middlesex, New Jersey

Wider weather episode

Thunderstorms with torrential downpours caused flash flooding in the Manalapan Brook basin in southeastern Middlesex County as a Doppler Radar estimated storm totals of between 6 and 8 inches fell over the basin. Damage was estimated at 10.25 million dollars as 308 homes, 25 apartments, 20 businesses and one industrial facility were damaged. Six homes suffered major damage (flooding into the first floor). About 800 persons were evacuated from Jamesburg, Spotswood, Helmetta and Monroe. A state of emergency was declared in Jamesburg. Motorists were trapped in rising flood waters and numerous basements were flooded throughout the county. The dam at Lake Manalapan was opened to prevent the dam from breaking. Utilities cut off the electricity and gas supplies to affected homes. In Jamesburg Borough, the downtown business district was flooded as was the Borough Hall and the Firehouse. About 340 persons were evacuated and some stayed at a Red Cross Shelter at a local school. Most of the downtown businesses were reopened within about one week. Damage in the borough was estimated at 3.4 million dollars. In Spotswood Borough, 360 persons were evacuated from about 120 homes. Damage was estimated at 2.2 million dollars. In Helmetta Borough, it was common to have five feet of water in basements. In Monroe Township, elderly residents from the Rossmoor Adult Community and the Monroe Village Retirement Community were evacuated. Damage was estimated at 1.4 million dollars. Flood waters receded on the 18th and only about 25 homes were without working utilities on the evening of the 18th. The Manalapan River at Spotswood had a a record breaking crest of 20.42 feet on the 20th. The previous record crest was 19.97 feet set in 1989. The period of record for the river gage is 47 years. Storm totals included 3.25 inches in Old Bridge and 1.62 inches in New Brunswick; neither location was in the core of the heaviest rain.

View location on OpenStreetMap → (40.4167, -74.4333)

Source: NOAA Storm Events Database, event_id 5468138. Narrative written by the NWS forecast office that issued the report.