In Your Own Back Yard
In Your Own Back Yard
By Anthony J. Gerst.
I am fortunate to live within ten minutes of what the Army Corps of Engineers and the Environmental Management Program (EMP) describe as the crown jewel of their wetland projects, Lake Odessa and the Port Louisa National Wildlife Refuge. Across this great country of ours, there are thousands of acres set aside for the enjoyment of the public. All too often, we as citizens overlook what is in our own back yard.
The Odessa Field Day had ten separate tour sessions and lectures going on. I will focus on the Environmental Management Program. Mike Griffin is the DNR Upper Mississippi River Wildlife biologist who gave this excellent presentation. Pictured above is the latest grand project undertaken by the EMP at the refuge. The rock wall is actually one of two low-flow overflow damns. These overflows were created to act as an aqua-equalization processor upon the levee system surrounding Port Louisa National Wildlife Refuge. Set at two different overflow levels they allow the refuge to partially flood from the down riverside before allowing the upriver waters to flow in.
The main objective here is to create a balance in the sediment flow and destruction of rushing waters. This will assist in maintaining a more natural setting within the wetland environs. The system will allow more flooding on the refuge as well, helping to bring natural restorative powers to this ecosystem. The process was designed to use natural elements with the assistance of concrete blocks, which have been wired together for the top section to cement the structure in place.
This aspect of the damn is then overlain with topsoil and seeded, the result can be clearly seen above. The finishing touch is an outlying rock wall that helps to defuse the overflow current and prevent erosion at points of ingress. So by creating this system the EMP has accomplished two goals.
1). They have implemented a system that will help to replenish the natural effects of the river upon the wetland.
2). This overflow system will prevent the costly and highly destructive occurrences of levee breaches in the preserve.
In 1956, congress approved and created the EMP. This year marks their 20th anniversary working on the Upper Mississippi River. They are the oldest, and considered the model in large river restorations. There are two departments contained within this organization. The long term resource monitoring department, which collects data on the 485 fish and wildlife species in the upper river, and maintains statistics on the river environ itself; such as flow, sedimentation levels, etc. This information is then applied by the second division, the Habitat Rehabilitation Enhancement Program.
In 1866 the Corps of Engineers, the parent administration of the EMP, created the first system of flow regulation on the Upper Mississippi, establishing a four-foot channel. In the 1930’s the current system was constructed that enlarged the channel depth to 9 feet. The EMP was created to offset the environmental damage that was being observed by the taming of the great river into a system of lakes and pools.
Since 1987, the EMP has undertaken 40 projects impacting 75,000 acres. Just above the Iowa-Illinois state border they have created new islands. Their new island designs replicate natural systems, and from past endeavors it is known that these will help create an abundance of wildlife and aquatic benefit to the area. For further information on the great efforts of the Habitat Rehabilitation Enhancement Program, please check out www.usgs.gov.
