Studies, Consultations Offer Encouragement For Nauset Dredging Project

By: Ed Maroney

Topics: Dredging

Selectmen Chairman Mark Mathison pointed to a spot on the table to illustrate areas in Nauset Estuary during a discussion with Geoff Sanders, Cape Cod National Seashore’s chief of natural resource management and science. Their chat continued after the Jan. 13 meeting of the Nauset Estuary Dredging Stakeholder Group.  ED MARONEY PHOTO

ORLEANS Recent studies of sediment types and shellfish resources, and preliminary consultations with regulatory agencies, have not dredged up any issues that would stall efforts to improve navigation in Nauset Estuary, a stakeholder group learned Monday.

Woods Hole Group senior coastal geologist Leslie Fields said core samples identified areas that were primarily sandy, which would mean dredged materials could be used directly to renourish beaches and dunes, and those that included percentages of silt, which would have to be separated hydraulically before such use.

Fields told the Nauset Estuary Dredging Stakeholder Group that a shellfish survey sample of the channel proposed to be dredged and the zone surrounding it found four bay scallops, 24 blue mussels, two soft-shell clams, 31 surf clams, and 269 quahogs. Based on the abundance of that creature, she said, regulators are “will likely want us to do mitigation in advance of dredging, maybe some relays outside of the channel.”

Preliminary conversations with regulatory agencies brought up some matters that must be addressed. Fields said MassWildlife’s National Heritage and Endangered Species Program wants information on alternative disposal sites (Eastham and Orleans are considering creating a dewatering basin just north of Nauset Beach), restricting the size of the basin and its frequency of use, and a close look at the overall impact of the project.

The National Marine Fisheries Service recommended that there be no dredging within 100 feet of eelgrass. “Right now, the dredge channel is not shown 100 feet away,” Fields said. “The town of Eastham has asked whether we could change the channel, and that potentially could solve the problem. I don’t know how long that channel will stay open. It’s not really where Mother Nature wants that channel to be.”

Longtime fisherman Steve Smith of Orleans was more sanguine. “I’ve gone along that area for 40 years,” the stakeholder group member said. “It’s never changed. I don’t see that as ever being a problem for navigation… I’d rather use the bigger (channel) size in other areas where we’d have problems maintaining that channel.”

Orleans Selectmen Chairman Mark Mathison, a lifelong sailor, took the opposite tack. He said silting is evident around the Snow Shore landing. To get to the Hole in the Wall, boats have to go through the mooring area, and that’s where the eelgrass is. “The silting is filling the channel,” he said. “I think that bottleneck right in front of Snow Shore and the massive area of silting… (will) choke off the estuary to the south of there. I don’t think we can ignore it.”

“To say that there’s eelgrass where the mooring is not true,” Smith said. “That eelgrass area at low tide is like a foot deep… We wouldn’t really be dredging through there.”

Selectman Kevin Galligan wondered whether the 100-foot dredging setback was absolute. “Maybe part of the channel could be slightly less than 100 feet,” Fields said. “(NMFS) would really object to the design we have (at this point) where the entire channel along the edge of the eelgrass” would be dredged. She added that a Capewide survey of areas from which eelgrass could be taken for transplanting elsewhere identified the estuary as “the prime donor bed with the most beautiful, lush eelgrass.”

NMFS also recommends not dredging in intertidal areas and following time-of-year restrictions to protect fisheries. It said the project must consider impacts on North Atlantic right whales, fin whales, sea turtles, sturgeon, piping plovers, and roseate terns, and advises using silt curtains while dredging.

To secure permission to use the dredged materials elsewhere for beach and dune nourishment, it’s essential to establish whether red tide cysts in certain areas to be dredged would fail to germinate when removed from their marine environment. WHG deployed study samples in dunes north of Nauset Beach on Jan. 7 to test this hypothesis. Weekly testing will continue through April. “This will help us validate whether desiccation, changes in temperature and salinity, result in killing those cysts,” Fields said.

The stakeholder group learned that the Cape Cod National Seashore will not be able to sign a memorandum of understanding with Eastham and Orleans and cannot participate as a voting member. Geoff Sanders, the Seashore’s chief of natural resource management and science, said National Park Service lawyers determined that would violate the federal Advisory Committee Act. “We still intend to be an active participant, simply in an advisory capacity,” he said.

Mathison sought assurance from Sanders that if the towns satisfied all the requirements of the federal and state government and the Cape Cod Commission, the Seashore, “as an entity of the federal government (would) accept other federal agencies’ acquiescence.”

“I don’t see why we would stand in the way of something NOAA agreed is fine,” Sanders said, but added, “We don’t know what the actual action is yet. For us to say the Seashore would not have any problems, I can’t say that.”

“I think we’re putting you on the spot,” Eastham Town Administrator Jacqui Beebe said. “Their job is to help us do this as best we can to not harm the environment and tell us if they have an issue. They have to retain their rights as a regulatory body… They’re here in good faith; they always have been.”

Sanders said the Seashore was not interested in “pulling the rug out from you two years from now.”

Next steps include signing the revised memorandum of understanding between the towns and setting up a formal stakeholders group that will also incorporate participation by representatives of regulatory agencies to keep preparation for permitting on a faster track through a special review process. Orleans Town Administrator John Kelly said a “funding estimate to get through another year of design and planning” would be needed this spring to take to town meetings. “I don’t need the full scope of work, but I need cost estimates to have an article in May,” he said.

Following the stakeholders session, the Orleans Dredge Advisory Committee met with WHG coastal scientist Adam Finkle to review his upcoming feasibility study on the town buying or otherwise securing the services of a dedicated dredge. He’s collecting data on the volume of past and potential dredging work in town and potential disposal sites, both public and private, and is scheduling site visits for the committee with county dredge program staff and with the Edgartown town dredge committee and its operators. Finkle will provide comparative data on hopper, hydraulic, and mechanical dredges. A final report with recommendations by the committee could be completed by summer.