Sandwich-02

Sandwich, Sagamore Marsh

41.774607, -70.520671

Comprehensive field assessment conducted in 2024

Upstream Invasive Species: Yes
Downstream Invasive Species: No
Invasive Species Notes: Phragmites limited to patches along top of channel bank. Further up in actual marsh, phragmites is limited to upland border
Additional Comments (2024): Creek has been channelized, straightened and had its banks reinforced with boulders all the way to the next constriction, a culvert about 250 ft upstream. Reinforcement has eliminated possibility of salt marsh along bank, debris buildup indicate slight constriction of flow. Area upstream of second culvert also had an armored bank for about 700 ft upstream. Scour hole in front of culvert again indicates slight constriction. Upstream marsh has large sections of low marsh with phragmites limited to upland fringe. Increasing tidal exchange may improve marsh community? Confirm with BH.

Legacy data from previous surveys and documentation

Invasive Species: Yes
Restoration Comments: The Sagamore Marsh restoration project is one of the largest wetland restoration projects ever undertaken in New England. Tidal flushing of the Sagamore Marsh was restricted in the mid 1930s when the Cape Cod Canal was widened and deepened, creating a fresh and brackish water system. A 48-inch diameter culvert was constructed as part of the Canal reconstruction to drain runoff from the marsh into the Canal. This culvert proved inadequate to provide sufficient tidal flushing to maintain the salt marsh. Various alternatives were examined to restore the salt marsh. The one that provides the maximum project benefit called for replacing the 48-inch culvert with two 6-foot high by 6-foot wide reinforced concrete box culverts under each road, installing electric sluice gates, deepening the man-made channel and widening the channel from 4-feet to 12-feet.

Operation Comments: Gates have never been fully opened. Concessions to listed four-toed salamander prevented full gate opening and complete restoration. Salamanders are now delisted, however US ACOE is working with DCR on a MOU before gate adjustments can be made.
Gate Comments: Culverts and automated tide gate were installed in 2001.

Other Comments: The Sagamore Marsh Project was under the direction of the U.S. Army Corps of Engineers and the Massachusetts Executive Office of Environmental Affairs. The National Marine Fisheries Service, U.S. Fish and Wildlife Service, and the EPA provided expert scientific analyses in support of this ecological restoration project. Project : Sagamore Marsh Tide gates that run under the Canal North Access Road, these were constructed through a Corps partnership agreement to restore Sagamore marsh. Constructed finished in April 2001 Waterbody : Sagamore Marsh/Cape Cod Canal Owner: This project was constructed by The Corps and is located on Corps Property. Permittee: There is no federal permit for the project. Maintenance and Operation Plan: It is attached Responsible Party for maintenance and operation: MA DCR Gate type: 2x electric sluice gates
External Data Comments: US ACOE Sagamore Marsh Operation and Management Plan September 2012 US ACOE Sagamore Marsh Project Cooperation Agreement 9.22.1999 (Other)