This is a box culvert that allows for kayaks and small boats to go through at certain tides. From the Woods Hole Group Alternatives study, alternative 2 was the preferred recommendation before open breaches were discussed. Paraphrasing from their report; While a 10 foot wide culvert fully restores tides to Mill Pond... this large opening may be more prone to shoaling due to reduced flow velocities through the culvert... Additionally, culverts that are 10 feet in width or greater have additional permitting requirements with MASSDOT...
The model determined that the 8-ft wide culvert restores tidal datums in Mill Pond to within a few tenths of a foot of the 10-ft wide culvert which is still an acceptable level of restoration. The narrower culvert width likely increase flow velocity to reduce shoaling while not require additional permitting. The 8-foot wide three-sided open bottom culvert was chosen as the second alternative, which was also set to a height of 8.5 ft.
In fact, an earlier study found there would be no additional hydrodynamic benefits to a culvert wider than 10 feet. To learn more about this alternative (alternative 2) read the June, 2022 Woods Hole Group report under Abandonment plan on this website.
The Select Board meeting to vote on the Mill Pond Breach will begin virtually at 5 pm. The Board is affected by large numbers of attendees. Please download goto meeting and use the link below to show your opposition to closing Mill Pond Road