Wetland Habitat Development with Dredged Material: Engineering and Plant Propagation

Marsh habitat development using dredged material as a substrate was shown by the Dredged Material Research Program (DMRP) to often be a feasible alternative to traditional dredged material disposal operations. This report synthesizes pertinent literature and research of the DMRP including six major marsh development field sites: Windmill Point in the James River, Virginia, Buttermilk Sound on the coast of Georgia: Bolivar Peninsula in Galveston Bay, Texas; Miller Sands, Columbia River, Oregon; Drake Wilson Island in Apalachicola Bay, Florida; and Salt Pond No.3, South San Francisco Bay, California. Guidelines for developing marsh habitat are presented: (a) planning the project in relation to the proposed site and project goals; (b) engineering construction of the site including dredging operations; (c) propagation, maintenance, and monitoring of the site as habitat, including potential problems that may be encountered; and (d) costs. Emphasis is placed on two major areas: engineering and plant propagation. Engineering aspects and design of potential sites are discussed and include protective and retention structures, substrate and foundation characteristics, dredging operations, and elevation and drainage requirements. Phases of plant propagation are detailed in the text tables: selecting plant species for the site, collecting and storing plant materials, selecting a propagule type, planting the site, maintaining and monitoring the site, pilot studies, costing the work, and allowing natural colonization