Our View: Make Chatham's Coastline Resilient

Editorial.

Perhaps the most interesting finding of the recently released draft coastal resiliency and management assessment of Chatham's east-facing shoreline is how closely changes since the 1987 break in North Beach are following the historical barrier beach cycle described by Dr. Graham Giese and others back in 1978. “Historical inlets to Pleasant Bay have migrated in a generally cyclical pattern that can be reasonably projected into the future,” according to the report, commissioned by the town and prepared by Applied Coastal Research and Engineering and the Center for Coastal Studies (where Dr. Giese, whose recent work informs the study, is director and scientist emeritus at the Land and Sea Interaction Program). The fallout from that breach was predictable in general. But the short term, year-to-year and month-to-month changes were a lot harder to predict; generally, storm events and period shifts in channels and erosion have a much more immediate, dramatic impact. Responses were not always appropriate, according to the report. A more systemic response is necessary to bolster the town's coastal resiliency, and because, as the report points out, “ongoing piecemeal efforts to maintain the Chatham Harbor system have not considered the ongoing dynamics of the multi-inlet system; therefore, overall have been ineffective.”

The report looks ahead 20 to 30 years, projecting that the barrier beach's evolution will be similar to how it happened in the years following the 1846 break in North Beach: The sand that now makes up North Beach Island will gradually migrate west and provide protection for areas of the inner shoreline. That will allow North Beach to continue to grow south and eventually once again serve as a buffer from storms and ocean waves for much of the eastern shoreline. While this is generally good news for coastal homeowners, mariners can expect to continue to face navigation difficulties for the foreseeable future.

In the interim, however, a range of mitigation measures will be necessary to deal with erosion and flooding “hot spots” as morphological changes occur. Some areas that are quiet now may experience more storm waves, according to the report, and tidal currents could scour deeper channels near the mainland shore (Minister's Point is currently experiencing this). A variety of responses are proposed in the study, which breaks the shoreline into five management areas; they range from using dredge material to build up shoals in the Linnell Lane area to creating an inland dike and raised roadway in the Little Beach neighborhood. These are the “micro” approaches that need to take place, with a more “macro” management plan looking long term toward the outcomes envisioned by the 1978 and this most recent report.

The one thing both reports makes clear is that changes along Chatham's eastern shoreline will continue into the middle of this century, and possibly beyond. An appropriate, and most importantly wholistic management strategy—which includes contingencies for dredging—is critical.