Corps of Engineers, DNR request comments on oyster restoration in shallower waters in Tred Avon River

Published July 19, 2016

EASTON, Maryland - The U.S. Army Corps of Engineers, Baltimore District (Corps), and non-federal sponsor Maryland Department of Natural Resources (MD DNR) have initiated a public review, July 19, 2016, on oyster restoration into shallower water depths than are currently allowed in the Tred Avon River Oyster Sanctuary in Talbot County. This work supports large-scale oyster restoration efforts in the Chesapeake Bay, as part of the Native Oyster Restoration Master Plan (2012) that was developed in coordination with several federal and state agencies.

The primary purpose of this environmental assessment (EA) is to evaluate extending oyster restoration from water depths between 9 to 20 feet mean low lower water (MLLW) to now also include water depths between 6.5 to 9 feet MLLW.  In addition to having an approved supplemental EA, construction of this project is contingent upon MD DNR concurrence with the restoration plans.  

A public meeting will be held August 9, 2016, from 6:00 p.m.-8:00 the Talbot County Community Center: 10028 Ocean Gateway Drive, Easton MD 21601. Written comments will also be accepted until the comment period closes August 19, 2016. 

Written comments can be sent via email to or via mail to:

U.S. Army Corps of Engineers, Baltimore District

Attn: Angie Sowers

10 South Howard Street, Ste. 11600

Baltimore, MD 21201

“It is necessary to restore oyster habitat across a variety of water depths that historically served as habitat in order to maximize coverage and diversity to achieve system-wide impacts,” said Angie Sowers, Baltimore District integrated water resources management specialist. “Oysters provide a wealth of positive benefits to the environment, including improved water quality.”

As part of the EA, the Corps is also evaluating reef restoration using alternate substrates such as rock and mixed shell as well as MD DNR’s work to plant spat-on-shell (baby oysters) on substrate and existing oyster reefs to meet a restoration target of 142 – 150 acres (including reef restoration and plantings) in the Tred Avon River, as outlined in the tributary plan The plantings on existing oyster reefs can occur between 4 and 20 MLLW based on the natural location of the reef. 

There is a total of 79 acres of reef restoration work identified in the Tred Avon River Oyster Restoration Tributary Plan. Of this total, 53 acres are planned at water depths between 6.5 and 9 feet MLLW, which would result in at least 6 feet of navigational clearance. The reefs are built from 6 inches to 1-foot in height.

No direct navigational impacts are anticipated from the proposed project. Proposed restoration sites that appeared to pose a navigational conflict based on some initial user feedback were removed from the plan. No substrate placement is proposed within federally-maintained channels. 

“We take any impediments to navigation seriously,” said Sowers. “We will work closely with the construction contractor to confirm the water depths above the restoration sites to ensure the proper navigational clearance. We also have a good working relationship with the Coast Guard.” 

The Corps plans to construct reefs at various water depths in the Tred Avon River sometime between December 2016 and March 2017. The reefs will be made from: rock only; combination of rock and mixed shell; or mixed shell only. The shell comes from processing plants in the mid-Atlantic region and is permitted to be imported and placed in the river. The rock is quarried in Havre de Grace, Maryland. Native oyster shell is the preferred substrate and will be used for reef restoration if it becomes available at a future time.

So far, the team has constructed 16 acres in deep water in the Tred Avon River. Previous National Environmental Policy Act (NEPA) documentation is approved for work that maintains an 8-foot navigational clearance.  

Oyster restoration in Maryland is a partnership between several agencies. The Corps restores reef structure to re-establish oyster habitat where it previously existed. MD DNR produces the spat-on-shell at the state-owned Horn Point Hatchery and provides for the planting of the spat-on-shell at restoration sites by the Oyster Recovery Partnership. The National Oceanic and Atmospheric Administration maps available restorable water bottom using sonar in conjunction with various groundtruthing methods and also funds the production and planting of seed oysters.

For more information, visit:
Sarah Gross

Release no. 16-020