Posted on November 17, 2020
In an article of the November 6 Falmouth Enterprise, Harbormaster Fraser rightly points out that annual dredging of the Eel Pond channel would be expensive and wasteful. Perhaps it’s time to consider a longer-term solution that could also help address a few additional issues like nitrogen loading and climate change.
Consider a flood gate installed across the channel that, during the winter months, is opened on falling tides and closed on rising ones. The net outflow current would tend to carry sand from the shallower Eel Pond into the deeper open sound. And during storms from the southwest, the gate could be closed to retard the deposition of sand in the channel from wave action. During summer months the gate could remain open during daylight hours for the convenience of boaters.
A secondary effect of this use of a flood gate would be to create a net slow current around Washburn Island. Instead of tidal water flowing in and back out, Waquoit Bay and Eel Pond would be flushed with fresh replacement water from the sound to reduce the nitrogen load—admittedly with somewhat less effect on the inland rivers connected to them.
As part of a long-term solution, installing a second flood gate across the channel at the mouth of Waquoit Bay should be considered. Operating in complementary fashion, opened on rising tides and closed on falling ones, a second gate would greatly increase the net current flow around Washburn Island with corresponding increase in flushing of nitrogen and dredging of the Eel Pond channel. Again, during summer daylight hours, both gates could remain open for boaters during which time the current flow rate would return to normal—as caused by the tides now.
With both gates installed, a third useful feature is achieved. On an anticipated storm surge, both gates could be closed at the lowest prior tide and could remain closed through the storm. Even if the storm surge were to overtop the dunes, the filling of Waquoit Bay might take considerable time, hopefully outlasting the surge. The resulting protection of properties along the whole inland water connected to Waquoit Bay could go a long way in justifying the high cost of floodgate installation—possibly including a reduction in the cost of flood insurance.
For those who think such use of floodgates to be overkill, I’d recommend examining the Fairhaven Hurricane Barrier that protects New Bedford Harbor. We have for centuries been adversely affecting our waterways through innumerable uncoordinated acts that cannot be simply reversed. Carefully considered action on a larger scale may now be warranted.
Wendell E. Bishop
Antlers Shore Drive