Although most of us are well aware of how dangerous and destructive a hurricane's high speed winds can be, people are often surprised to find out that the deadliest aspect of hurricanes often tends to be the flooding that they cause. Hurricanes are often responsible for extensive coastal storm surges, as well as flooding further inland.
In fact, these inland floods can inflict destruction on areas that are actually several hundred miles from the coast, as a result of hurricane-related rainstorms deep inland. Ironically, some of the worst flooding tends to happen when the inland rainstorm is not accompanied by the hurricane’s high speed winds, as less severe winds end up allowing rainfall to concentrate in one particular area.
As almost two-thirds of the US population lives in coastal states, hurricanes pose a very significant threat to this country, especially when the danger is extended due to inland floods.
When a hurricane or its accompanying rainstorm heads toward your community, make sure you take it seriously. Remember that the threat of inland flooding can end up being the worst aspect of the entire storm. Find out whether you live in a flood risk area, and pay attention to your local authorities' instructions, along with road conditions in your area. Create a plan before a storm hits, so that if you are told to evacuate, you can do so right away.
If you have time, ahead of the storm, take steps to protect your home from water damage. For example, have sandbags or other water barriers on hand (learn how to build sandbag dam), and make sure you have a reliable sump pump in your basement, along with a backup system like a battery backup sump pump or water powered sump pump.
If you find yourself in the midst of flooding, take the floodwater seriously. It only takes 2 feet of water to sweep a car away entirely; while a mere 6 inches can cause you to lose control of your car while driving.
Here is an example of the destruction caused by a recent hurricane, due to its winds, storm surges, and inland flooding.
Flood Example: Hurricane Irene, August 2011
Hurricane Irene was an incredibly destructive hurricane that hit the Caribbean and US East Coast in the late summer of 2011. Before its effects had passed, the storm would be responsible for 56 fatalities and caused an estimated $15.6 billion in US property damage, the seventh most expensive in history.
In addition to wind damage, including countless uprooted trees and downed power lines (7.4 million homes lost power), Irene caused extensive flooding. Coastal areas in the US experienced a storm surge of water, and extensive river flooding occurred further inland. In at least 6 states, rivers reached hundred-year flood levels.
The Outer Banks in North Carolina were particularly hard hit by flooding during Irene. As rain water filled the rivers that empty into the Outer Banks’ sound, the hurricane’s winds simultaneously acted to push these rivers the opposite way - back upriver. Once the hurricane passed, this pent-up supply of water surged back down the rivers, into the sound, and overwhelmed many areas in the Outer Banks, including Rodanthe, Salvo, and Waves. In some locations, the floodwater’s depth reached 7 feet or more, ruining many houses and other buildings.
In New York City, water surged into the harbor and flooded certain parts of the west side in lower Manhattan. Further up the coast in Connecticut, a storm surge in the Long Island Sound destroyed many homes near the waterfront.
In New York State and northern New Jersey, extreme rainfall resulted in immense river flooding, with 11 rivers in NJ setting new water level records and floods persisting for days. Rushing floodwater washed out roads and train tracks, crippling infrastructure as roads stayed closed and train service remained halted after the flood waters were gone.
The town of Washingtonville, in the southwestern part of New York State, experienced particularly bad flooding, with up to 8 feet of water on the ground in places. This onslaught was brought about by extensive flooding from the Moodna creek. After the flood passed, the area was left severely distressed, with many homes ruined, dozens of trees toppled, and large objects like cars destroyed by floodwater.
The nearby Hudson River empties into the New York harbor and its level actually fluctuates with the ocean tide in the harbor. On the east side of the river, the city of Poughkeepsie experienced flooding along parts of its waterfront, like the riverside Waryas Park, as a storm surge of water hit while the river was already at its high tide level. Further north, in Albany, the Hudson’s high tide level reached a substantial 11 feet above sea level. Nearby, the Schoharie Creek overwhelmed its banks, destroying approximately one-third of all the buildings in the small upstate village of Schoharie.
In addition to its impact on human lives, the flooding from Hurricane Irene left a lasting effect on the environment. During the storm, sewage spilled out of overwhelmed treatment facilities in many areas, contaminating the water that flooded out of rivers, spilled across streets, and entered buildings. The rushing storm water altered the landscape of rivers and streams via erosion and by carrying sediment to new places.
In the Hudson River, which usually contains a significant amount of ocean saltwater, the abundance of freshwater from rain and ground runoff actually emptied the entire river of salt, an extremely rare phenomenon. Besides this change in salt content, the river’s temperature dropped noticeably, as cooler rainwater entered it. Both changes instantly altered the living environment for all the plant and fish life in the river. Ecological studies performed after the hurricane showed fewer plants taking root in the river, affecting its habitat for fish. As expected, the fish population has also dropped, versus past years.
Hurricane Irene’s impact on people and the environment will no doubt be studied for decades to come. Although the hurricane’s destruction was immense, these studies have allowed us to learn how to better prepare for future storms, and that knowledge will continue to improve as we glean further insight into Irene’s causes and effects through new research.
This article is intended for informational purposes only. Before beginning any construction project at your home or taking steps to prepare for an emergency, please ensure that you take necessary safety precautions; consult construction professionals, your local authorities, and disaster safety experts whenever necessary. Water Damage Defense accepts no responsibility for the actions you take during an emergency or as you prepare for one.