NewburyportNews.com, Newburyport, MA

May 3, 2013

Sand dunes a big answer to PI problems

Bill Plante's North Shore
Newburyport Daily News

---- — A few weeks back, I came by a copy of a 1971 “How To Build and Save Beaches and Dunes” bulletin of the University of Rhode Island.

It consists of only 12 pages, the last of which, entitled “Useful Reading,” lists 18 publications.

I then did a computer search that responded with 1,560,000 related hits.

The result? Plum Island is but one of thousands studied by NASA in recent years, and apparently is better off by way of its location on the northeast Atlantic seaboard than those in other areas of the world.

While other regions show an average annual loss rate of about an eighth of an inch a year, our northeast Atlantic coastal loss appears to be lower.

Key word? “Appears,” and the study goes on.

Taking such matters personally, and generally making the worst of what I make of them, Plum Island hasn’t lost all that much during my considerably long lifetime.

It just seems so. Sporadically over time, because it’s fortunate to be on the down side of what sand comes down the Merrimack River, the movement is generally southerly.

Think not? Call up Google Earth on a computer, enlarge the near offshore view and marvel at the amount of sand making is way from the river’s mouth to the southerly end of the island.

How to capture it?

That’s what the handbook “How To Build and Save Beaches and Dunes” is all about, and, happily enough, some of that is working at Plum Island.

It is rich with sand dunes. Not all islands are. Like football linemen on defense, however, they’re vulnerable. That’s why there are wooden walkways at the protected area.

What is in process at Plum Island is historic. It has been there a very long time. Over time homes have been grievously assaulted. There have been total losses and extraordinary costly preservation.

That section has long been vulnerable because construction has been on the foremost dunes at the center. Structures built on dunes in that area do not leave much room for nourishment.

Beach and dune buildings on primary dunes is what the handbook is about.

It’s not a proclamation against building on them. It does support rebuilding of them with heavy equipment as has been done by way of the desperate, expensive response south of the center.

Its major emphasis, however, relates to using nature to breast the sea from invasion. There has been some loss believed to have been caused by the breaks in the south jetty, but not nearly as much as was lost more than a half century ago.

The rebuilding north of Plum Island center has been successful if somewhat diminished. Dune-holding grass has taken root, and while some of the planting has been lost, a substantial area appears to be establishing itself.

I was surprised to learn from the booklet that such plants go dormant in summer heat, but do well in springtime and early fall.

There is hope, as well, for new sand particles, and there is apparent hope for stability if the following recommendation takes root.

“Dunes should be constructed in front of property to be protected and across areas where sand has been blown or washed away. They should be built above the high tide line.”

The major point is this.

“Natural dunes along the shore are formed and protected from erosion by vegetation. Foliage holds sand in place and traps wind-borne sand. As sand accumulates, the vegetation grows up through it. With sustained deposits and vegetative growth, dunes grow larger and remain stable.”

The proof of that is to be found northerly of 50th Street, where once, 50 years or so ago, the sea had made itself felt much as it has these past few years at the center.

What we are witnessing will pass because it always has. Unfortunately, what will go with the passing depends on whether the lessons at hand take everlasting root.

Unfortunately, farming beach fronts is not really why we occupy them.

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Bill Plante is a Newbury resident and staff columnist. His e-mail address is plantejr@comcast.net.