Notes from an Environmentalist. The Army Corps is Right. Forget the Gyre Build the Plum Island weir.

Dave Vine stands near where nature has built a new weir in the Merrimack River’s South Jetty.

                The Corps is Right;

      Forget the Gyre, Build the Weir!

Readers of these articles know I have been known to twit the Army Corps of Engineers on occasion, but this time they have it right.

The problem is, a private organization hired by the state introduced a new shiny term into the South Jetty lexicon. The term is gyre; a circular system of currents that they say is causing the erosion on Reservation Terrace.

Their solution would be to reconfigure the spur of the jetty.

 But the Army Corps of Engineers has done its own study that shows that simply cutting a weir into South Jetty would reverse the reservation Terrace erosion by restoring the natural flow of sand. No need to touch the spur which never worked in the first place.

But at the June 21^st meeting of the Merrimack River Beach Users Alliance several members glommed onto the new term and spent an inordinate amount of time proving that the Corps owns the spur and insisting that they reconfigure it to interrupt the hypothetical gyre.

Bad idea!

I’ve spent months collecting plankton samples in mid-ocean gyres and on the leaky gyre over Georges bank and I can tell you this is no gyre. In fact Chris Hein the coastal geologist who has spent years studying Plum Island on a long term National Science Foundation grant calls this a dispersion zone.

So, now is not the time to overcomplicate what is actually a simple straightforward solution, cut a weir into the jetty to restore the natural flow of sand to Reservation Terrace.

The only real issue to resolve is exactly where to place the weir and that is pretty easy to figure out as well.

Just walk out onto the jetty and see where our past winter’s southeast storms disheveled the jetty creating a natural weir that has already led to the impressive growth of North Point Beach, and the burial of old Coast Guard broadcast facility under 5 feet of new sand. Now we just have to make the natural weir a little deeper.

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Bill Sargent will be leading a beach tour of North Plum Island starting at the Lighthouse Parking lot at 10am on Sunday. Cost $10.