BATH — The Department of the Navy in Bath is seeking a 10-year permit from the U.S. Army Corps of Engineers to dredge portions of the Kennebec River from Bath to Phippsburg to allow the passage of Bath-built destroyers.

The Navy expects maintenance dredging will be needed every three years, according to a news release.

The first dredging would happen during the winter of 2019-2020 and would move 80,000 cubic yards — roughly the volume of 20 Olympic swimming pools — of sand and sediment from the bottom of the Kennebec River between Bath and Phippsburg, particularly in shoal-prone areas. Shoals are large wave-like formations of sand that accumulate on the bottom of the river.

Up to 50,000 cubic yards will be removed from Doubling Point and dumped in the river near Bluff Head to make the area around Doubling Point 31 feet deep. At the river mouth, up to 20,000 cubic yards will be taken until the river is 29 feet deep and disposed of near Jackknife Ledge. Both disposal sites have been used repeatedly in previous dredging projects.

The dredging process takes approximately a month to complete, using a hopper dredge and/or a mechanical dredge. The U.S. Army Corps of Engineers did not disclose how much the process costs.

These maintenance dredges ensure the Kennebec is deep enough so the military vessels made by Bath Iron Works can move downriver to open ocean. BIW’s most recently christened Arleigh Burke-class destroyer, the future USS Daniel Inouye, will leave the Bath shipyard in 2020 for Pearl Harbor, Hawaii.

Tim Dugan, a spokesperson for the U.S. Army Corps of Engineers, said that portion of the Kennebec River federal navigation channel is “authorized by Congress to be so wide and so clear. … (BIW) needs to release those ships in a timely fashion. They need those areas of the river free and clear of debris.”

Eleven Arleigh Burke-class destroyers and one Zumwalt-class are under contract for delivery in the next 10 years.

A BIW-built Arleigh Burke class-destroyer has a draft (depth of the hull that sits underwater) of about 30 feet, and a Zumwalt has a draft of 27.6 feet.

BIW spokesman David Hench referred questions about the dredging to the Navy but stated in an email: “Maintaining a navigable channel in the Kennebec River is necessary for safe passage of ships and is essential to our business and our Navy customer’s goal of delivering the quality ships it needs for the nation’s fleet.”

The last dredging of the Kennebec River in April 2017 drew criticism from environmentalists. Federally protected Atlantic salmon, short-nosed sturgeon and Atlantic sturgeon live and spawn in the river, and the dumping of the dredged materials could harm seeding shellfish in Phippsburg, critics argued.

The 2017 dredging was an “emergency” dredging as it was needed to allow the USS Rafael Peralta, an Arleigh Burke-class destroyer, to depart from Bath, according to previous reports. Shortly before the ship’s departure, it was discovered the ship couldn’t navigate the river, even at high tide, thus an emergency dredging was needed to clear the way.

The Department of the Navy acknowledged the impact dredging the Kennebec River and depositing the material poses on the river’s ecosystem. In a news release, the U.S. Army Corps of Engineers said the Navy is consulting with the National Marine Fisheries Service.

“Both the Navy and Army Corps of Engineers are very concerned about the environmental impacts of the dredging,” said Colleen O’Rourke, a spokesperson for the Department of the Navy in Bath. “As required in the permitting process, we extensively coordinate with both federal and state environmental agencies to ensure that all requirements are met.”

The U.S. Army Corps of Engineers outlined turbidity, or the amount of sediment suspended in the water, as one potential problem for species living in the river because it decreases both visibility in the water and the amount of light able to pass through the water.

Dugan said dredging in the winter reduces the impact on the river’s ecosystem because endangered species aren’t spawning then.

“The impacts will be minimal and of short duration,” he said.

David Grey, chairman of the Phippsburg Shellfish Commission, said, “We’re totally fine with them dredging; we support BIW, as long as they don’t do it in the summer when the shellfish are seeding.”

Grey said when the river is dredged during the spring and summer, “the shellfish are more or less suffocated” when the dredged material is deposited in shellfish harvest areas in Phippsburg.

The U.S. Army Corps of Engineers issued a public request for comment, as required by the Clean Water Act of 1977. They encourage comments from members of the public. Comments should be submitted in writing to Nick Livesay, Director, Bureau of Land Resources, Department of Environmental Protection, 17 State House Station, Augusta, ME, 04333-0017 or [email protected].

 

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