The Ramsar Convention's resources on Wetland Restoration

The STRP Expert Working Group on Wetland Restoration

Restoration Approach: Dredged Material

Wetland type: Marshes and swamps

Background: Dredging is often required to construct or maintain navigable waterways or flood control channels. In many cases, dredged material is treated as a waste product and either dumped in deep water or stored in landfills (sometimes called "confined disposal facilities" or CDFs). However, dredged material can also be used to create or restore wetlands on shallow, unvegetated bay bottoms. In the United States, dredged material is frequently used to create salt marshes on the Gulf and Atlantic Coasts, but it has also been used to create mangrove habitat in Florida and both marshes and swamps along the shores of the North American Great Lakes.

Advantages: Dredged material provides an alternative method of disposing of dredged material that can provide environmental benefits. In many cases, wetlands can be created in locations that protect navigation channels from wind and wave action. Often, creation of dredged material wetlands can be completed at costs below those of traditional dredged material disposal methods.

Disadvantages: Creating dredged material marshes displaces natural shallow-water habitat. If fine sediment is used to create dredged material marshes, it must be confined within earthen berms or other structures until it consolidates. If dredged material marshes are created on exposed shorelines, physical protection (riprap barriers, geotextile tubes, etc.) may be required to prevent rapid erosion.

Further Information:

Shafer, D.J. and W.J. Streever. (In press). A comparison of 28 natural and dredged material salt marshes in Texas. Wetlands Ecology and Management.

Streever, W.J. (In press). Spartina alterniflora marshes on dredged material: A critical review of the ongoing debate over success. Wetlands Ecology and Management.

A hydraulic dredge pumps sediment to form a wetland.

A salt marsh created from dredged material near Houston, Texas, USA.

Return to STRP Wetland Restoration index page

For further information about the Ramsar Convention on Wetlands, please contact the Ramsar Convention Bureau, Rue Mauverney 28, CH-1196 Gland, Switzerland (tel +41 22 999 0170, fax +41 22 999 0169, e-mail ). Posted 8 January 2001, updated 15 February 2002, Bill Streever and Dwight Peck.