National Wildlife Refuge
|10728 County Rd X61
Wapello, IA 52653
Phone Number: 319-523-6982
|Visit the Refuge's Web Site:
|Port Louisa Refuge provides resting and feeding habitat for migratory waterfowl, such as wood ducks.|
Continued . . . In the 1800s, as European settlers built towns and prepared land for agriculture, the Mississippi River became an increasingly important travel and trade route. However, inconsistent water levels limited the navigation seasons, and rocks, sandbars, and submerged logs presented a danger to boat traffic.
Congress began authorizing a series of navigation channel improvements to be implemented by the Corps of Engineers. Eventually, thousands of wing dams and closing dams were built to constrict the main channel and increase its depth.
In 1930, construction began on a series of locks and dams to provide a 9-foot-deep navigation channel for heavy barge traffic. These dams created a series of 26 navigation pools extending from St. Paul to St Louis. The Corps was also given flood control responsibilities and began building levees along the river. This system of locks, dams, and levees is still in use today.
These navigation and flood control projects dramatically altered natural water level cycles in the river. Sediment from soil erosion filled wetlands, reduced water clarity, destroyed fish spawning grounds, and prevented the growth of aquatic vegetation. Hundreds of thousands of acres of floodplain forest and prairie were lost to agriculture and other development. Although some lands, such as Port Louisa Refuge, are designated for protection of fish and wildlife, the overall amount and quality of wildlife habitat continues to decline.
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