Flood — Somerset, New Jersey

2010-03-13 to 2010-03-17 · near Gladstone, Somerset, New Jersey

Event narrative

In Somerset County, Bound Brook, Manville and Green Brook were hardest hit by the heavy rain and flooding. There were 1,300 flood related emergency calls and 46 water rescues in the county. In Bound Brook, about 600 residents were evacuated to the borough's high school gym and a Presbyterian Church. Another shelter was opened at the Raritan Valley Community College. The Salvation Army served meals. Businesses were flooded along Main Street and East Second Avenue also flooded. The flooding affected six less blocks than it did in 2007. In Manville, 200 residents in the Lost Valley section and along Duke Parkway were evacuated. A shelter was opened at the Veterans of Foreign Wars Hall. The wall of one home collapsed. About 165 homes were flooded. Flood damage for the most part was limited to basements and foundations. Damage was estimated at 2.5 million dollars. In Green Brook, a nursing home was evacuated. Roads and bridges were closed near the Green Brook. In Hillsborough Township, U.S. Route 206 was flooded at the Raritan River and cut the township off from the northern half of the county. The Van Veghten Bridge over the river was closed. In Montgomery Township, traffic on U.S. Route 206 was very heavy because it was the only roadway over the Millstone River that was open. In Rocky Hill Borough, County Route 518 was closed through the afternoon of the 14th because of flooding. Roads were also closed due to flooding in Bernards Township, Bedminster Township and Far Hills Borough.

The North Branch of the Raritan River at North Branch was above its 12.3 foot flood stage from 749 p.m. EST on the 13th through 1054 a.m. EDT on the 14th. It crested at 16.44 feet at 330 a.m. EDT on the 14th. Farther downstream, the North Branch of the Raritan River at Raritan was above its 10 foot flood stage from 912 p.m. EST on the 13th through 1257 p.m. EDT on the 14th. It crested at 13.9 feet at 415 a.m. EDT on the 14th, the highest crest since Hurricane Floyd in September of 1999. Farther downstream, the North Branch of the Raritan River at the village of South Branch was above its 7 foot flood stage from 426 p.m. EST on the 13th through 345 p.m. EDT on the 15th. It crested at 13.71 feet at 315 a.m. EDT on the 14th.

The Main Stem of the Raritan River at Manville was above its 14 foot flood stage from 944 p.m. EST on the 13th through 640 a.m. EDT on the 15th. It crested at 21.57 feet at 915 a.m. EDT on the 14th. It was the sixth highest crest on record and the highest since April of 2007. Farther downstream. the Raritan River at Bound Brook was above its 28 foot flood stage from 1102 p.m. EST on the 13th through 1130 a.m. EDT on the 15th. It crested at 36.04 feet at 1045 a.m. EDT on the 14th. It was the fourth highest crest on record and the highest since April of 2007.

The Millstone River at Griggstown was above its 10 foot flood stage from 1203 p.m. EST on the 13th through 332 a.m. EDT on the 17th. It crested at 18.62 feet at 645 a.m. EDT on the 14th. Farther downstream, the Millstone River at Blackwells Mills was above its 9 foot flood stage from 729 p.m. EST on the 13th through 706 a.m. EDT on the 16th. It crested at 16.15 feet at 1030 a.m. EDT on the 14th, the 5th highest crest on record and the highest crest since April of 2007. Farther downstream, the Millstone River at Weston was above its 12.4 foot flood stage from 1154 p.m. EST on the 13th through 757 a.m. EDT on the 15th. It crested at 17.83 feet at 1030 a.m. EDT on the 14th.

The Pike Run at Belle Mead was above its 7 foot flood stage from 504 p.m. EST on the 13th through 317 a.m. EDT on the 14th. It crested at 9.02 feet at 945 p.m. EST on the 13th. The Bound Brook at Middlesex (along the county line with Middlesex County) was above its 9 foot flood stage from 627 p.m. EST on the 13th through 605 p.m. EDT on the 14th. It crested at 13.15 feet at 430 a.m. EDT on the 14th. The Stony Brook at Watchung was above its 14.5 foot flood stage from 835 p.m. EST through 1119 p.m. EST on the 13th. It crested at 14.8 feet at 1045 p.m. EST.

Event precipitation totals included 5.62 inches in Montgomery, 5.41 inches in Bridgewater, 5.13 inches in Hillsborough and 4.94 inches in Somerville.

Wider weather episode

Four days of rain, heaviest on the 13th, culminated in major flooding in the Passaic and Raritan Basins and flooding throughout New Jersey. Four day storm totals averaged around 2.5 to 6 inches with the highest amounts in the Raritan and Passaic Basins. It was the worst flooding in the Raritan Basin since April of 2007 and the worst flooding in the Passaic Basin since April of 1984. Over 1000 people were evacuated in Morris and Somerset Counties. Damage was estimated at 30 million dollars as thousands of homes and businesses were damaged. In Morris County alone, about 1,300 homes and businesses were damaged. New Jersey Governor Chris Christie declared a state of emergency on March 14th. Periods of rain started during the morning of the 12th and fell at its heaviest on the 13th. The heaviest rain fell during the morning in the southern third of the state, afternoon in the central part of the state and in the afternoon into the evening in the northern third of the state. Periods of lighter rain persisted into the 14th and 15th which slowed the recession of streams and rivers in the area..

The heavy rain was caused by a slow moving low pressure system that had a tremendous fetch of moist air from the Atlantic Ocean. The low pressure system moved from the South Carolina coast on the morning of the 12th, into Virginia on the morning of the 13th, to Delaware on the morning of the 14th and then drifted slowly east over the next two days as it was captured by an upper level system.

The flooding occurred on the weekend when eastern daylight time began. Some of the river flooding started on Eastern Standard Time and ended on Eastern Daylight Time, we apologize for any confusion this causes.

View location on OpenStreetMap → (40.7200, -74.6500)

Source: NOAA Storm Events Database, event_id 222424. Narrative written by the NWS forecast office that issued the report.