Flash Flood — Montgomery, Pennsylvania

1996-09-08 to 1996-09-09 · near Southern, Montgomery, Pennsylvania

Wider weather episode

Thunderstorms, which "trained" or moved over the same locations of Southern Montgomery County, caused widespread flash flooding, caused the death of a couple in Abington and about $20 million dollars in property damage. Up to 10 inches of rain within a three hour period. The 10 inches of rain was measured at the water treatment plant off Fitzwatertown Road in Abington. This corresponded well with the Doppler Radar rainfall estimates of locations surrounding the severe flooding. Tropical moisture left behind by the remnants of Hurricane Fran was a major contributor to the torrential downpours. States of emergency were declared by several Montgomery County townships. Governor Ridge declared a disaster emergency for the county on the 10th and the county was declared a federal emergency disaster area the night of the 13th.The most significant flooding occurred along the Sandy Run Creek in Abington. The creek runs about 100 to 150 feet behind the houses on Madison Avenue. Madison Avenue was where the flooding related deaths occurred and where most of the eight destroyed houses were. Heavy rain began falling around 430 p.m. EDT and by 530 p.m. EDT water rescues were starting. A 73-year-old man went into the basement of his Madison Avenue house to start bailing out the water. His 71-year-old wife moved their vehicle to higher ground. Around 630 p.m. EDT when she returned, her husband was in cardiac arrest. She called the paramedics and remained with her husband. As the creek continued to rise, it flooded most of the homes on the south side of Madison Avenue. The flood waters literally pushed in the back foundation of the house and the couple was trapped and drowned within the rising wall of water within their basement. The water line reached up to 8 feet above ground level. The National Weather Service Survey team estimated the creek at its highest was about 14 feet above the creek bed. The flooding along Madison Avenue was exacerbated by a fallen tree that acted as a debris dam across the creek just downstream from the Madison Avenue neighborhood. As the water continued to rise, debris built up against the downed tree. After the water receded about a dozen motor vehicles were removed from that portion of the creek bed. The Johnston and Fernwood neighborhoods had the second worse damage in the township. They were located less than half a mile upstream from Madison Avenue. The Sandy Run Creek also runs about 75 feet on the south side of Fernwood Avenue. Backyard garages, swimming pools and several vehicles were destroyed. At least two dozen homes sustained flood damage. The Roslyn Elementary School suffered about $750,000 in flood damage as water rushed downhill from the Hillside Cemetary into the school. Water levels reached 10 feet within the school's basement and destroyed its cafeteria and boiler. The flooding extended upward into the first floor and damaged 12 of the 21 classrooms. Flooding also damaged six classrooms in the Saint John the Cross School. About 30 people attending a baby shower escaped injury by evacuating from the Rosyln Boy's Club about 30 minutes before the building collapsed. A rentention basin filled and then flooded the Willow Grove Shopping Center. In all, within Abington Township 8 homes were destroyed, most along Madison Avenue. There were also about 550 homes and apartments that were damaged, 120 of which had major damage. About 75 businesses were either damaged or destroyed, 80 roads and bridges and several rail lines were damaged. The Sandy Run Creek was declared a major debris site. Pennsylvania State Route 152 or Limekiln Pike was badly damaged and was expected to remain close for about a month. The Sandy Run Golf Course was under 8 feet of water.Other locations in Montgomery County also were flooded. About 40 homes in Springfield Township were damaged as the Wissahickon Creek flooded. The Sandy Run Creek drains into the Wissahickon. The Oreland section was the hardest hit with residents from 7 homes evacuated. In Upper Dublin Township, 7 homes were damaged. Ten vehicle rescues were performed from 530 to 930 p.m. EDT. A 14-year-old was stranded in a tree for 45 minutes. Sections of Fitzwatertown Road were washed out. In Upper Moreland Township, 23 businesses, 11 houses and 7 apartment buildings suffered flood damage. Vehicles were floating in the Willow Grove Shopping Center. In Whitemarsh Township, 30 people were rescued by boat from the Day's Hotel. Twenty-seven other persons were evacuated and a dozen cars became submerged in flood waters. Three people were rescued from a van's roof. In Cheltenham Township, school was canceled on Monday the 9th, after flooding damaged 35 of their school buses and 20 of its vans. Countywide damage was estimated at $20,000,000. In addition to the 10 inch rainfall report at the water treatment plant off Fitzwatertown in Abington, 5.42 inches of rain fell at the Willow Grove N.A.S. in Horsham Township and 4.6 inches in Glenside (south of Abington Township).

Source: NOAA Storm Events Database, event_id 5580591. Narrative written by the NWS forecast office that issued the report.