Release no. 17-012
CONCORD, Mass. (March 14, 2017) – The U.S. Army Corps of Engineers, New England District plans to perform emergency maintenance dredging of portions of the authorized, 27-foot deep, 500-foot wide Federal navigation channel in the lower Kennebec River between Phippsburg and Bath, Maine.
The emergency dredging is needed to provide safe passage of the USS RAFAEL PERALTA, a U.S. Navy Destroyer, scheduled to set sail from Bath Iron Works and transit the channel on or about April 27, 2017. The RAFAEL PERALTA has been deemed critical to USN Fleet Operations and to National Defense.
Hydrographic surveys of the Doubling Point area (near Bath) and Popham Beach area (at River mouth) indicate that the channel has shoaled to -18.4 feet below Mean Lower Low Water (MLLW) across almost the entire 500-foot wide channel at Doubling Point and to -16.7 feet below MLLW across more than half the authorized channel near Popham Beach. Based on this, there is concern that the RAFAEL PERALTA cannot transit the channel safely even during high tide. The emergency dredging would restore the channel to its authorized dimensions and will provide safe operating depths for the RAFAEL PERALTA and subsequent future transits by other vessels of this type.
“A hopper dredge would remove about 70,000 cubic yards of clean sand,” said Project Manager Bill Kavanaugh, of the Corps’ New England District, Programs/Project Management Division in Concord, Mass. “Approximately 50,000 cubic yards of material will be removed from the Doubling Point area and approximately 20,000 cubic yards of material will be removed from the Popham Beach area.” The shoals in the channel near Doubling Point consist of massive sand-waves. As part of this proposal, advance maintenance may be performed to remove the sand-waves in the vicinity of Doubling Point to a maximum elevation of -32’ MLLW in an effort to improve the chance that adequate depths will endure. The 50,000 cy to be removed from the channel at Doubling Point includes approximately 35,000 cy of advance maintenance dredging.
Material dredged from the Doubling Point area will be placed in the previously used in-river placement area north of Bluff Head in about 95-100 feet of water. Material dredged from the Popham Beach area will be placed in the previously used 500-yard diameter nearshore placement area located about 0.4 nautical miles south of Jackknife Ledge and in about 40-50 feet of water. Contingent upon the availability of funds to perform this work, emergency dredging would begin on or about April 19, 2017 in the channel at Doubling Point to clear the most critical shoals, and absent of significant weather-related delays, dredging will take about 3-5 weeks to complete.
The proposed work is being coordinated with: U.S. Fish and Wildlife Service; U.S. Environmental Protection Agency; National Marine Fisheries Service; Maine Department of Environmental Protection; Maine Coastal Program, Department of Agriculture, Conservation and Forestry; Maine Department of Transportation; Maine Historic Preservation Office; and The Passamaquoddy Tribe. An Environmental Assessment for the emergency dredging of the Kennebec River is being prepared.
The public notice, with more detailed information, is available for review on the Corps website at: http://www.nae.usace.army.mil/Missions/Navigation/PublicNotices/.
Public comments on the planned emergency dredging work should be forwarded no later than March 28, 2017 to the U.S. Army Corps of Engineers, New England District, Programs/Project Management Division (ATTN: Mr. Bill Kavanaugh), 696 Virginia Road, Concord, MA 01742-2751 or by email to firstname.lastname@example.org.
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