7
Conclusions
Weishar, Stauble, and Gingerich (1989) completed an initial reconnaissance
study of the effects of a new breach through Nauset Spit which occurred due to an
extratropical storm on 2 January 1987. The breach quickly formed a new inlet
which has become the main inlet in a complex four-inlet system on the southeast
ocean coast of Cape Cod at Chatham, MA. That study ended in 1989 and the need
is now present to update the evolution of the inlet/barrier-bay system which has
continued to evolve for the past 13 years. The inlet's geomorphic features are
continuing to evolve and have not yet reached an equilibrium condition. Maintain-
ing a navigation channel into Aunt Lydia=s Cove is still a problem for the Town of
Chatham commercial fishing fleet and the U.S. Coast Guard that maintains a
rescue vessel at the Fish Pier at the harbor. This new study has evaluated the
growth and change occurring over the past 13 years and provided guidance on
inlet evolutionary trends, regional sand management, and navigational channel
stability to assist the District in its navigation planning.
Historic Evolution - Areas of Concern
Although 13 years is a short time frame in the average 140-year cycle of
Chatham Inlet, certain patterns have emerged in how the inlet is evolving with the
prevailing coastal processes. The use of historic aerial photography allowed the
mapping of morphology changes in the inlet's channels, shoals, and adjacent
shorelines. By comparing the distinct migration patterns of each feature, trends in
spatial and temporal evolution were shown. A complex interaction of morpho-
dynamics was identified and distinct patterns in evolution were shown. As the
inlet continues toward a dynamic equilibrium of forces and morphologies, several
areas of concern have developed.
Aunt Lydia's Cove entrance channel and anchorage
As the inlet has evolved, the main navigation channel trouble spots have been
the entrance channel into Aunt Lydia's Cove and the achorage at the Fish Pier.
The orientation and depth of this channel has been controlled by the location and
evolution of the north flood shoal, Tern Island, and the Tern Island south shoal.
All three of these features existed in the preinlet state as remnant sand features.
The initial channel orientation even before the 1987 inlet formation was in a
general east-west direction, connecting a dominant west flood channel with the
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Chapter 7 Conclusions
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