The Alabama State Port Authority released details of its Upper Mobile Bay Wetland Creation project this week, a proposal for the beneficial use of dredged material from the port of Mobile to create 1,200 acres of wetlands about a mile south of the Causeway.
The $2.5 million planning phase of the project, funded through Bucket 2 of the Restore Act, seeks to design a use for an estimated 6 million cubic yards of sediment removed annually from Alabama’s Mobile Harbor federal navigation channel and adjacent public berths. According to promotional materials, the upper reaches of Mobile Bay has lost 10,000 acres of wetlands over the last century and this project “will create wetland where it can thrive … and be beneficially used for habitat.”
During a presentation this week, Vice President of Internal/External Affairs Judith Adams said the project will have an unrelated benefit.
“It also benefits the port and the taxpayer because it will lower the costs for disposal,” she said. “There are a number of permitted dredge disposal areas, depending on where you’re dredging in the channel, but those are really costly options.”
Adams emphasized that the project is unrelated to the $360 million effort to deepen and widen the shipping channel, and the material used in the wetland creation will originate from a relatively small area near the mouth of the Mobile River during routine dredging operations over the next 20 years.
Meg Goecker, senior coastal scientist at Moffatt & Nichol, said this project has been in the works for 10 to 12 years and is similar to the Lightning Point wetland restoration project the firm recently completed in Bayou La Batre, but on a much larger scale.
“This is an opportunity to try to bring back wetlands in an area where it’s conducive to bring wetlands back,” she said. “By constructing this project, the sediments would remain in the upper Mobile Bay system, and then would be beneficially used to create some of these wetlands that we have lost over the years. We know these wetlands are some of the most productive in the world and you can’t say enough about what these wetlands do for the delta. So we really feel this project is a win-win that addresses the need for dredging and for remedying this historic loss of wetlands.”
The Port Authority is gathering public input on the design concept of the project but intends to begin by designing the first 100-acre plot by the end of the year and applying for permits from the U.S. Army Corps of Engineers. A containment dike rising three feet above the high tide line will encompass the entire project area, but will eventually be strategically breached to allow natural tidal influence and access to humans and aquatic species. Once filled with sediment according to the design standards, planners believe the wetlands will be naturally seeded and inhabited.
“Every year, if the port dredges 350,000 cubic yards from its berth, we can create almost 40 acres of wetland with that,” Goecker said.
The site was chosen after studying the depth of the bay, the wind and wave climate, and the stability of sediments within. Project Manager Mary Beth Sullivan said the site would be divided into 40- to 60-acre cells using internal containment dikes and it’s likely two or three cells could be constructed simultaneously.
“It’s really important to note that the final step in creating this wetland habitat is to open up the cells to Mobile Bay,” Sullivan said. “The resulting cell will be actively managed to create tidal creeks and to allow connectivity and access for the public. When this project is complete, you will see more of the habitat that you see along the Causeway and Bayway further out in Mobile Bay.”
Goecker said although the dredge material is essentially a “soup,” the containment system will prevent it from leaching into the bay before it settles, and the project will be monitored for permit compliance throughout its construction.
“The Restore Act Bucket Two is an environmental bucket and they don’t want us to put just a giant mountain of muck out there,” she said. They want habitat. And we’re trying to make the Gulf Coast whole from what the oil spill did and the ultimate goal of the project is to make that habitat.”
More information is available at https://uppermobaywetlands.com/.
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