FORT WAYNE – Construction on a multimillion-dollar project to physically separate the Great Lakes and Mississippi watersheds in Eagle Marsh could begin next summer.
The Great Lakes and Mississippi River Interbasin Study Newsletter says federal officials have been doing extensive computer modeling of the complicated water flows in the area and found that their proposed solution should not cause further flooding.
Fort Wayne sits along a continental divide, which led to its nickname as the Summit City: The eastern half of Eagle Marsh, on the citys southwest side, drains into the Great Lakes by way of Junk Ditch, the St. Marys River and the Maumee River. The western half of the marsh drains into the Mississippi River by way of the Graham-McCulloch Ditch, the Little River, the Wabash River and the Ohio River.
When there are floods in Fort Wayne, Junk Ditch can flow backward, flooding overland through Eagle Marsh and into the Graham-McCulloch Ditch, allowing species to move from one basin to the other, including Asian carp, a huge, voracious fish that has invaded the Mississippi River system. Also called the Snakehead, officials fear that if it gets into the Great Lakes, it could devastate the sport fishing industry there. To prevent this, the Indiana Department of Natural Resources built a temporary fence across the marsh in 2010.
Federal officials announced in August they had narrowed the options they were studying to two: Reconstructing an existing berm along the Graham-McCulloch Ditch at a cost of $5.5 million, and a similar, but more ambitious plan that would reconstruct the berm, remove another berm and construct wetlands. That plan would cost $7.7 million.
Technically, both plans are still on the table, said Betsy Yankowiak, director of preserves and programs for the Little River Wetlands Project, which owns and oversees Eagle Marsh nature preserve.
There is not a final design yet, the permitting process hasnt even started yet, Yankowiak said. Theres still a lot of work to do.
Officials now are looking at a blend of the two plans: Rebuilding the Graham-McCulloch Ditch left-bank berm to an elevation that will prevent flood waters from crossing basins, and deconstructing part of the right-bank berm to allow floodwater storage.
Federal officials said the updated modeling shows that only minor wetland mitigation efforts would be required to prevent further flooding on Junk Ditch caused by the higher berm.
Yankowiak said the focus on the Asian carp has been good because it has raised the awareness of invasive species, but it also shows the problems created by a world that seems to get smaller every day.
Its just a snapshot of what were dealing with right now, she said. Who knows whats going to be brought into the country in the next 10 or 20 years?
Among the biggest threats is viral hemorrhagic septicemia virus, known as VHS. Fences and screens may prevent fish getting through, but not a virus.
Officials at Eagle Marsh say theyre happy to work with federal officials on the project, but note that once construction is complete, it could take up to five years to restore the areas where the work was done.