A marsh is constructed in several stages. First, the levees are placed and shaped, and weir boxes are built into the levees to allow for drainage and circulation. Once this is done, shoreline protection is put around the levees to prevent them from eroding. When all levee material has settled, the interior, which will eventually become marsh, is filled. Detailed calculations must be made as to exactly how much material to place in the marsh cells so that, when it settles, it will reach inter-tidal level precisely between 0.6 and 1.4 feet above mean low tide. The settling and water drainage process takes approximately two years. As the material settles, the BUG looks for the adequate formation of creeks and ponds. Once the material has reached inter-tidal level, vegetation is planted. If creeks and ponds are not forming to the BUG Group’s satisfaction, they will use machinery to create them. Creating the levees Atkinson Marsh Once the levees have been properly placed and secured into marsh "cells," the inside of the marsh cell is filled with the dredged material Planting Vegetation Smooth cordgrass (Spartina alerniflora) is the plant species used to populate the project marsh sites. This plant is best suited for sites inundated daily by tides because of its tolerance for a wide range of salinities (salt levels), soil types and water levels. In the past, the majority of marsh creation projects relied on transplanting smooth cordgrass from native stands. However, this process is limited by the availability of healthy marsh that is vigorous enough to sustain some loss and near enough to the transplant site so the vegetation will survive during transport. To overcome these limiting factors and protect natural marsh, the U.S. Department of Agriculture’s Natural Resources Conservation Service is cultivating new sources of smooth cordgrass. Cultivation begins with harvesting seeds from plants in the natural marshes. Harvested seeds are potted in soil trays in a greenhouse, where they germinate within 10 to 20 days. Then seedlings are transplanted into small, individual pots that are placed in gravity flow ponds, where they grow large enough to transplant. In Galveston Bay, a smooth cordgrass (Spartina alernflora), a hearty all-weather plant, is germinated in greenhouses before being planted on the wetland sites Middle school students from Houston-Galveston Metroplex at the August 2008 planting event sponsored by Artist Boat, Gateway to the Gulf Program View of Fred Hartman Bridge from New Work Cell of Atkinson Marsh The BUG first transplanted vegetation at the Gorini Marsh. The marsh was divided into one-acre plots for comparison of various planted methods. The plant spacing within plots varied from 3-foot to 48-foot centers, including plots without planting for measurement of natural colonization and establishment. From studying the marsh and vegetation growth, the Group determined that 24-foot centers are the best way to plant man-made inter-tidal marshes in Galveston Bay.