Why do the Pompton and Passaic rivers around Wayne, Singac and Totowa in New Jersey flood so badly when heavy rain hits? The area has flooded three times since December, thanks to a parade of powerful storms sweeping through the region.
In a nutshell, the answer is simple: This area is a choke point along a network of streams and rivers that are all trying to drain their water into the Atlantic Ocean.
The network of rivers is known as the Passaic River Watershed – an area touching nine counties in northern New Jersey and New York. All the rivers in the Passaic River Watershed drain to one point: the mouth of the Passaic River at Newark, where the water enters the Atlantic Ocean.
The problem is that the majority of the entire river network in the watershed converges at one point – where the Passaic and Pompton rivers merge -- near Wayne. It produces a choke point, or bottleneck, in the river. After a heavy rain event, when three, four or more inches of rain have to drain through this one section of river, you can guess what happens. Traffic gets backed up like rush hour traffic on the George Washington Bridge. In this case, it’s not cars that jam, but water. And that leads to flooding.
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The reason flooding on the Passaic River near Singac and Little Falls happens a day or more after the rain stops is simple. It takes time for the runoff to travel from the far reaches of the watershed down miles and miles of river before arriving at the choke point.
And, depending on how much rain has to drain to the Atlantic, it could take several days for flooding to subside after the Passaic first floods.
