Notes from an Environmentalist; Plum Island Mystery Solved.
The remains of the Coast Guard facility are now buried under 6 feet of new sand.
Nature vs. Models
Plum Island, Massachusetts
On April 5th the Army Corps of Engineers presented their models for fixing Plum Island’s South Jetty.
Gone were the previous suggestions of altering groins and spurs, building seawalls and breakwaters, or modifying the bar at the mouth of the jetty.
What remained was building a weir in the jetty, the only solution that ever really made any sense.
But now the question was where to build the weir; closer to shore, or further out on the jetty.
Their models predicted that if they placed the weir further out most of the sand flowing through the jetty would wash back into the mouth of the Merrimack River.
It was only by building the weir closer to shore that more of the sand would nourish Reservation Terrace.
On April 7th I returned to the jetty to see what nature had to say about manmade models.
It was the day before the “Great American Eclipse.” And, the same conditions that had made the eclipse so spectacular, the fact that the new moon was about 40,000 miles closer to the earth than normal had also raised the highest tides of the year. It would be perfect conditions to observe the workings of nature’s weir.
It was high tide and large waves were breaking on the oceanside of the jetty. But previous storms had built up a ridge of sand that was about twenty feet above mean sea level and five feet higher than the jetty.
The ridge was so high that waves could not wash over it near the center of the jetty the way they had when we first observed this in 2017. But they were able to shear off the sand on the Oceanside of the beach and wash it through the jetty.
But instead of building up a new beach on the opposite side of the jetty, the sand appeared to be flowing back into the mouth of the river.
The Army Corps or Engineers model had predicted the best place to build the weir and nature had corroborated their findings. Now it was just a matter of the Corps to cut through their red tape to get funding and permission to build; nature only needed wind, water and time.