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Flash Flooding & Safety
Densely populated areas have a higher risk for flash floods than rural areas. Flash floods can occur within minutes or hours of a heavy rainfall, and waters can rise as high as 30 feet or more. Even small streams and creeks can flood rapidly and cause damage. Flash floods are usually caused by slow-moving thunderstorms.
According to the National Weather Service, "Flash floods are short-term events occurring within six hours of the causative event (heavy rain, dam break, levee failure, rapid snowmelt and ice jams) and often within two hours of the start of highintensity rainfall.” Flash floods can move homes and cars, uproot trees and destroy bridges. Because floods happen with little to no warning, residents in low-lying areas are particularly at risk.
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Floods are one of the most common weather hazards in the United States. They can happen anywhere at any time of year. According to the American Red Cross, flash floods are the No. 1 weather-related killer in the U.S. Almost half of all flash flood fatalities are vehicle related, according to the National Weather Service. If you're driving and approach a water-covered road, turn around. Just 6 inches of water can stall a vehicle, and 2 feet can float most cars, trucks and SUVs. Here are some other tips to stay high and dry:
Know your proximity to rivers, streams and dams
During heavy rain, avoid underpasses, underground parking garages and basements
Avoid hiking or camping if thunderstorms are predicted
Develop an evacuation plan for your family
Don't walk in water above your ankles; you can be swept off your feet in as little as 6 inches of rushing water
Turn off the electricity and other utilities During heavy rain, Township storm sewers can become blocked with debris causing flooding in the street. In preparation of any rain event, Township crews do attempt to clean storm inlets to make sure they are able to collect water from the street. If you notice debris on top of a storm inlet before or after a storm, contact the Township immediately. If your roadway becomes flooded during a storm, call 911 immediately so emergency personnel can respond to close the road to traffic.
What is Impervious Surface?
Impervious Surface- A surface that prevents the infiltration of water into the ground. Impervious surfaces include, but are not limited to, streets, sidewalks, pavements, driveway areas, or roofs. Any surface areas designed to be gravel or crushed stone shall be regarded as impervious surfaces. Impervious surfaces reduce the amount of rainwater that can be absorbed into the ground. When there is less ground for water to penetrate, it can quickly flow directly into stormsewers and creeks, increasing the likelihood of more frequent and more severe flooding. Additionally, pollutants are unable to penetrate an impervious surface. Rainfall may carry these pollutants directly into our waterways resulting in water that is unfit for wildlife or recreational activities.
Water runoff from an acre of paved surface is approximately ten to twenty times greater than an acre of grass. Materials such as crushed stone, porous concrete, and pervious pavers can provide various amounts of infiltration but are not considered 100% pervious. To minimize the impact of water runoff, impervious surface coverage is limited to a maximum percentage per property, which varies by municipality. Any additional increase of concrete, brick, asphalt, etc. on a property may require a building permit prior to construction.
SEWER BACKUP AND FLOODING INSURANCE !
Sewer backups and flooding can cause devastating property damage and are not covered by standard homeowners’ insurance policies. The majority of these claims are the responsibility of the property owner.
Sewage from sanitary sewer lines occasionally back up into houses through drain pipes. These backups not only cause extensive water damage that is difficult and expensive to repair, but also create health hazards. Haverford Township is not responsible for damages caused by sewers, drains and sump pumps except under limited/special circumstances provided by the PA Municipal Immunity laws.
Township residents must be aware that they should review their homeowner’s, flood and sewer backup insurance coverage with their agent/insurance company in order to properly protect their personal residences—probably the most valuable tangible asset that we all have.
Coverage for Sewers, Drains and Sump Pumps: This valuable coverage is not included under your standard homeowner's policy but can be purchased by endorsement for an additional premium. Flood Coverage: Flood coverage is not included under your homeowner’s policy. However, flood insurance is available under the National Flood Insurance Program (NFIP) and can be obtained through your insurance agent or broker.
