Flash Flooding in New Jersey, March 22 to 24, 1999

Heavy rain affected all of central and northwest New Jersey. This caused flooding of smaller streams throughout the area and later some of the major creeks and streams including the Rockaway and Raritan Rivers. In addition the heavy rain caused the usual highway and poor drainage flooding throughout the region. Heavy rain began during the late afternoon of the 21st and continued into the early morning of the 22nd. Storm totals exceeded two inches in many locations and this was too much rain to keep streams and rivers within bankfull. The heavy wet snow from the previous weekend left the ground in nearly saturated condition. With much of the flooding starting during the early (Monday) morning of the 22nd, no serious injury or property damage were reported.In Somerset County, the Millstone River at Blackwells Mills reached its 9 foot flood stage at 10 a.m. EST on the 22nd, crested at 10.5 feet at 7 pm. EST on the 22nd and was back within bankfull at 9 a.m. EST on the 23rd. The Raritan River at Manville was above its 12 foot flood stage from 6 a.m. EST through 11 p.m. EST on the 22nd. It crested at 14.83 feet at 3 p.m. EST on the 22nd. Farther downstream, the Raritan River at Bound Brook crested at 28.36 feet at 630 pm. EST on the 22nd. The river was above its 26 foot flood stage from noon EST on the 22nd through 2 a.m. EST on the 23rd. In Morris County, The Rockaway River flooded both above and below the Boonton Reservoir. Above the reservoir, it was above its 5 foot flood stage from noon EST on the 22nd through midnight EST on the 23rd. It crested at 5.21 feet at 345 p.m. EST on the 22nd. Below the reservoir, it was above its 5 foot flood stage from 11 a.m. EST on the 22nd through 230 a.m. EST on the 24th. It crested at 6.28 feet at 325 a.m. EST on the 23rd. The Passaic River briefly crested at its estimated flood stage of 19 feet in Pine Brook around midnight the night of the 24th. In Mercer County, the Assunpink Creek in Trenton reached its 7 foot flood stage at 3 a.m. EST on the 22nd, crested at 7.60 feet at 7 a.m. EST and was back within bankfull at 10 a.m. EST on the 22nd. Storm totals included 3.75 inches in Oak Ridge (Morris County), 2.90 inches in Pottersville (Somerset County), 2.85 inches in Lambertville, (Hunterdon County), 2.78 inches in Stewartsville (Warren County), 2.65 inches in Reigelsville (Warren County), 2.64 inches in Somerville and Bridgewater, (Somerset County), 2.62 inches in Boonton (Morris County) and Califon (Hunterdon County), 2.51 inches in Washington's Crossing (Mercer County), 2.48 inches in Blackwells Mills (Somerset County), 2.45 inches in Flemington (Hunterdon County), 2.31 inches in Princeton (Mercer County), 2.02 inches in Long Valley (Morris County) and 1.99 inches in Hightstown (Mercer County). The low pressure system responsible for the heavy rain moved northeast from Atlanta, Georgia the morning of the 21st to Albany, New York the morning of the 22nd.