A Connecticut company will begin dredging Cape Porpoise Harbor in November for the U.S. Army Corps of Engineers and hopes to remove 30,000 cubic yards of sand which will to be hauled to the Cape Arundel Disposal Site. FILE PHOTO

KENNEBUNKPORT — A $1.68 million contract has been awarded to a Connecticut company to perform dredging of portions of the Cape Porpoise Harbor in Kennebunkport.

According to the U.S. Army Corps of Engineers, New England District, Coastline Consulting and Development LLC of Branford, Connecticut will  use a mechanical dredge and scows to remove material from the Mean Lower Low Water channel and anchorage, and the 6-foot-deep Mean Lower Low Water channel and then haul it to the Cape Arundel Disposal Site. The sediment to be removed will allow boaters to maintain safe navigation in these portions of the waterway and returns the 6-foot channel to authorized and maintained dimensions.

U.S. Army Corps of Engineers Project Manager Coral Siligato said that the dredging operation is scheduled to take place between Nov. 1 and Feb. 28, 2020 in order to minimize impact to natural resources in the harbor.

“Natural shoaling processes have reduced available depths to as little as 1 foot in the 15-foot Mean Lower Low Water channel and anchorage, and 2 feet in the 6-foot MLLW channel, making navigation hazardous or impossible at lower stages of the tide,” Siligato said earlier this year.

She said the project will dredge about 30,000 cubic yards of primarily fine- and medium-grain sand, and silt from about 12 acres of the authorized project area.

“It will maintain the required authorized dimensions of the 6-foot MLLW channel and will maintain safe navigation to 10 feet in the 15-foot MLLW channel and anchorage,” Siligato said.

An official request for dredging was submitted by the town of Kennebunkport as deteriorating conditions have made navigation of a dredged channel difficult leading to the sea below the highway bridge at Kennebunkport. In recent years, boaters have been advised to exercise extra caution when entering the harbor at ebb tide and in southerly weather with heavy seas running as a result of sediment buildup.

In 2013, the harbor entrance dropped to about 4 feet at low water with the approach to the port marked by two buoys and two spindle day beacons which mark the principal dangers and of late the best approach for boaters entering the harbor is east of the marker buoys.

According to Siligato, the U.S. Army Corps of Engineers last dredged the harbor in 1976 when a mechanical dredge removed more than 123,000 cubic yards of sediment from the 15-foot channel, 15-foot anchorage, and 6-foot channel, and then deposited the material at the Cape Arundel Disposal Site.

She said that the contractor will be authorized to dredge the harbor 24 hours per day, seven days per week.

In recent years, ports along the southern Maine coastline have experienced long delays getting approval for federal navigation dredging projects, which has prompted the Southern Maine Planning and Development Commission to conduct a feasibility study of purchasing and operating hydraulic dredging equipment to perform the work on a more timely basis.

If all of dredging is not completed in one season, the project will occur the following season within the allowable dredge window. This window between November and March was specifically chosen to limit adverse impacts to federally-listed endangered and threatened species in the harbor area as well as avoid the eelgrass growing season, and the spawning of winter flounder and shellfish.

Cape Porpoise Harbor consists of three coves and the U.S. Army Corps of Engineers first began to work in the area around 1900. In 1950, about 200 feet of the harbor was deepened, straightened and widened through removal of existing ledge rock between Goat and Folly islands. The rock was removed to a depth of 18 feet, and the channel was widened at that time to an expanse of 200 feet.

Through the years, crews from the U.S. Army Corps have constructed a 930-foot-long entrance channel, 16-feet deep, extending through the bar west of Goat Island to a point between Milk and Bass islands. That particular channel is 450 feet long and 200 feet wide through the bar, and then 480 feet long and between 200 and 500 feet wide between Milk and Bass islands.

Crews have also created a combined channel and anchorage extending 2,150 feet from a point between Milk and Bass islands to the Kennebunkport town wharf on Bickford Island which is 15 feet deep and has a maximum width of 600 feet. A 2,000-foot-long channel, some 6 feet deep and 100 feet wide, extends from the town wharf to the head of Porpoise Cove.

— Executive Editor Ed Pierce can be reached at 282-1535 or by email at editor@journaltribune.com