In 1973, the State of Wisconsin initiated a lawsuit against the Corps of Engineers related to the effects of their operation and maintenance program on the Upper Mississippi River and revealed that sediment from uplands and stream banks, as well as current methods of channel maintenance (especially dredging and placement of dredged material), were damaging the fragile backwaters, marshes, and sloughs for which the river is famous.

The lawsuit and subsequent river planning revealed that little information was available on many other components of the river, and the lack of information would make it almost impossible for government agencies or Congress to evaluate alternative means to manage the river in a more balanced way without considerable additional study. Since that time, numerous partnerships have been formed to gather more information about the river, beginning with what those in the industry call “The Great One.”

The Great I: A Study of the Upper Mississippi River just passed its 43rd birthday in September and is significant in its depth and range of river planning. It set the stage for ongoing interagency collaboration and long-term data collection and stressed the urgency in our decision making.

“Although previous actions have enhanced fish and wildlife habitat, we are realizing we may be on the threshold of irreversible deterioration. The greatest need appears to be for intelligent and rational management of this recourse that is so important to our lives.” (Great I: A Study of the Upper Mississippi River, Volume One, Chapter II, II-1, September 1980)

Perhaps The Great One could have predicted that in just four years, a ¼ mile island would emerge at the head of Lake Pepin where it had been accumulating beneath the water all along. Much of what builds up at the head of the lake ( ~ 80% ) comes from erosion in the Minnesota River watershed, the second largest tributary to the Upper Mississippi River. Some of the material settling at the head of the lake comes from a much closer source just upstream, where other islands are washing away.

In 1994, the Long-Term Resource Monitoring Program (established in response to the Great I), produced a special report on recreational boating impacts on the Upper Mississippi River System in Pool 4, near Red Wing, Minnesota.*

Beginning in 1992, a series of field investigations examined potential physical and water quality changes associated with recreational boating on the Upper Mississippi River. Investigations were designed to measure and compare erosion rates along bank shorelines and document water quality changes associated with boating activities between river miles 790.7 and 787.5 on the main channel and river miles 792.5 to 786.5 on the Wisconsin channel.

The report found that boat waves, alone or in combination with other contributing factors (like water levels, boat traffic density, presence of shoreline stabilization features, etc.), may be responsible for river shoreline erosion. The report was not able to quantify the amount of erosion that could be attributed to one specific variable. The study strongly suggested that the passage of many large, deep draft boats are the major contributing influences for shoreline erosion prevalent along the Main Channel.

Nearly 30 years has passed since the study was published, and members of the Red Wing Wildlife League are frustrated that no clear process exists to protect their land from washing into the river. The island their members use for seasonal hunting and recreation is 75 feet narrower than it was 50 years ago.

The League has tried a few innovative techniques to break up the wave impact, which have been successful on small streams. Along the main channel of the Mississippi River, however, they are ineffective. In 2003, the Minnesota Department of Natural Resources looked more closely at shoreline and water quality impacts from recreational boating on the Mississippi River.

In that study they surmised that shorelines along the main channel of the Mississippi River, when exposed to significant recreational boat traffic, erode at an average rate of 2-3 feet per year. An estimate of sediment released to the river from Lock and Dam 3 to the head of Lake Pepin indicates that streambank erosion contributes 82,600 cubic yards of sediment annually.**

The Minnesota Department of Natural Resources stated a clear need for additional water surface use management of the Upper Mississippi River to maintain a careful balance of the complex river environment. Among those include “its value as a wildlife sanctuary and rich mosaic of ecological communities; an important fishery resource; a corridor for commercial commerce; and as a provider of an extensive variety of recreational opportunities… certain aspects of current water surface use practices are in direct conflict and must be addressed through a collaborative and adaptive management process.” 

In places along the river where management practices have been established to provide stability and mimic natural processes, you can see the habitat and wildlife return. 

*Johnson, S. 1994. Recreational boating impact investigations - Upper Mississippi River System, Pool 4, Red Wing, Minnesota. Report by the Minnesota Department of Natural Resources, Lake City, Minnesota, for the National Biological Survey, Environmental Management Technical Center, Onalaska, Wisconsin, February 1994. EMTC 94-S004. 48 pp. + appendixes (2 pp.)

**Shoreline and Water Quality impacts from Recreational Boating on the Mississippi River, Minnesota Department of Natural Resources, Mississippi River Landscape Team, 2003