Man versus nature — you know who wins

Mark NaleIt was a beautiful day in June when I stopped at the Bodie Island Light Station – part of the Cape Hatteras National Seashore on North Carolina's Outer Banks.

While there, I got into an interesting discussion with a park ranger about the nearby Bonner Bridge, which spans Oregon Inlet. The Route 12 bridge is the only way for automobiles to continue farther south on the Outer Banks.

The ranger asked if I had driven across Bonner Bridge and if I knew about the controversy surrounding it. Since this was news to me, he shared the story.

In 1846, a storm punched a hole through the barrier island, forming what is now called the Oregon Inlet — a water passageway between Pamlico Sound and the Atlantic Ocean. It is a major thoroughfare for charter boats heading from the mainland out to sea to fish in the Gulf Stream.

Inlets move and are formed and closed by strong natural forces, such as the 1846 hurricane. Since 1846, the Oregon Inlet has migrated south over 2 miles –  at an average rate of 66 feet per year. This is fine, except that in 1963, $4 million was spent (mostly from our federal tax dollars) to build a 2.7-mile bridge spanning the inlet. Now, it is one thing to hit a moving target with a shotgun, and yet another to hit it with a bridge.

The inlet still attempts to move and the state of North Carolina attempts to stop it.  In fact, since 1987, over $60 million has been spent to protect the $4 million Bonner Bridge and NC Route 12 on the Outer Banks. According to the ranger, it is rumored that the center supports of the bridge have been totally undermined by ocean currents. A new $215 million bridge will be built, but where do you construct it?

Controversy surrounds the bridge location, construction and its environmental impacts. Unfortunately, the question stirring the embers is location, not whether it is smart to build the bridge or not – but maybe it should be.

So what does a bridge in North Carolina have to do with Pennsylvania?

We are lucky in that we do not have to deal with the mega-forces produced by an angry ocean, but we do have a similar problem. Pennsylvania's streams and rivers also move, but houses and businesses built near them and the concrete bridges that cross them stay where they were constructed. If you are a streamside landowner, you need to understand stream movement.

As an example – the hollow in which I live is about 250 yards wide, with the stream on my property currently near the extreme northeastern edge. Dig down anywhere in the valley floor and you will find rounded, water-tumbled sandstone. Of course, this means that, during the past 1,000 years or so, the stream has been located at different spots all across the valley. In fact, it is this meandering of the stream that created the flat-bottomed valley floor in the first place.

In 1978, I constructed a small bridge crossing the stream where it was at the time. During the 35 years since I built the bridge, the stream has moved 8 feet to the west.  I cannot move the bridge, so limestone boulders and recycled chunks of concrete persuade the stream back toward the bridge opening.

I am not alone. The same thing happens all over Pennsylvania. Streams and rivers move and people attempt to stop that natural movement.   It is man versus nature.  I know where I would place my bets, Who do you think will win?

Categories: Pennsylvania – Mark Nale

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