Sixth in a series of Big River articles on the Army Corps Navigation Study.

Reading Between the Lines -- the Corps’ Cumulative Effects Study

By Reggie McLeod
From Big River August 2000

What isn’t in the recently released “Upper Mississippi River and Illinois Waterway Cumulative Effects Study” may be more revealing than the contents of the three-volume, 572-page report.

This study is part of the Army Corps of Engineers’ $54-million study of the feasibility of expanding the locks and dams to accommodate more shipping on the Mississippi River. The final, environmental part of the study is scheduled to be released when the entire study is released in October.

Volume One of the Cumulative Effects study examines the physical changes in the rivers after the lock-and-dam system was installed, from about 1940 until 1989. Volume Two examines the ecological changes. The studies also list what changes are likely to occur from 1989 to 2050.

They do not paint an encouraging picture: islands are eroding away and backwaters are filling with silt. As beds of rooted submersed plants disappear, fish lose habitat. The study also lists the impacts of power plants cooled by river water, agricultural runoff, urbanization and other modern activities that damage the river ecosystem.

However, the study carefully sidesteps two very important issues: What have the locks and dams done to the river; and is the big river in big trouble?

What Have the Locks and Dams Done to the River?

The period of the study begins after the locks and dams are in place. It does not consider how the river functioned as a natural system. Thus, it avoids asking whether the existing lock-and-dam system makes sense when one considers the true environmental costs.

A lot of detailed information was gathered on the river in the 1920s and 1930s, to prepare for building the locks and dams. But that pre-lock-and-dam data was not directly used in the Cumulative Effects Study.

“In some cases they only had information from 1974 and 1989,” explained Gretchen Benjamin, Mississippi River planner for the Wisconsin Department of Natural Resources and a member of the Navigation Study’s Environmental Coordinating Committee.

“They had no way to know how degraded the system was in 1974.”

The methods used to project future environmental changes “made no sense to us at all,” she added.

Is the Big River in Big Trouble?

The conclusions of the Cumulative Effects Study are very general, explaining why, for instance, groups of wildlife or sections of the river are in decline, but not attempting to measure the decline or estimate the costs of the damage.

The study ignores evidence that the Upper Mississippi River ecosystem may already be stressed to the point that it has begun to collapse. Many river biologists believe that this happened to the Illinois River in the 1950s, when many plant, duck and fish populations declined very quickly. In the late 1980s large beds of underwater plants, such as wild celery, all but disappeared in much of the Upper Mississippi. While some plant beds have partially recovered, they may never return to their previous state, taking with them thousands of acres of habitat for young fish and the small animals that fish and other wildlife eat.

These plants also helped buffer the erosive action of wind and waves and helped clear the water.

The study also ignores other environmental damage, such as the damage caused by stone riprap, which blocks turtles from climbing up the bank to lay eggs.

Ken Barr, environmental leader for the Navigation Study, admits that information about the depth of backwaters and side channels immediately after the locks and dams were built is limited. Information about seasonal conditions is also lacking, because most of the old aerial photographs were taken during “flat pool” conditions, when the flow is low and all of the dam gates are in the water.

He said he is concerned with the environmental limits of the system. “At what point can a couple of more boats cause enough turbulence that the plants will not be able to continue photosynthesis?”

He is also concerned about the rapid disappearance of submersed, rooted plants. “Below Pool 13 [Clinton, Iowa] there are none left.”

One positive change is a dramatic decline in the need for dredging the Main Channel. Farmers practicing better soil conservation have reduced the soil washing into streams and rivers on the Upper Mississippi Watershed. Also, more dams on streams and rivers may be holding back more soil, which may be causing problems in the Mississippi’s tributaries.

Coming in October

The complete Navigation Study will only estimate the costs of repairing damage caused by the expansion it proposes — probably extending locks 20 through 25, extending two locks on the Illinois River and adding guide walls and moorings to other locks. These costs will probably add up to about $10.5 million a year. Most of the money will go to projects managed by the Corps.

“We have not endorsed that, because we didn’t think those dollar figures represent the impacts,” Benjamin said.

The plan favored by the Corps provides an economic benefit of about $21 million, so if the environmental mitigation costs increase much, they will cancel out the benefit, she pointed out.

Despite arguments by economists and biologists, the final study will ignore the environmental costs of the existing lock-and-dam system and will not explore its overall economic and technological feasibility.

Environmental groups are certain to haul the Corps into court when the final study is released. The economic part of the study is already under scrutiny by the National Science Foundation, Congress, the Pentagon and the Office of Special Council, because Corps economists accused their bosses of changing the numbers to make expansion look economically feasible (see “Did the Corps Cook the Books?”, Big River, March 2000).

Benjamin said that many committee members are unhappy with the limited scope and methodologies of the Cumulative Impact Study. “We don’t think we are being listened to all that well.”

“In 90 and 91 we almost had a system-wide collapse of the environmental system. We don’t think the system can handle what is out there today,” she said. “We have outlined those concerns time and time again.”

The Navigation Study will cost about $54 million and take a total of seven years. The most important results will be revealed by the shape of what is missing, by the important questions that were avoided. Those tough questions will have to be asked in the courts and at the hearings that follow in the wake of the study, at enormous expense and adding further delay to addressing problems that threaten the river’s future.

Barr cannot comment on the economic part of the study, but he said his bosses have not pressured him to change any of the environmental part of the study.

Reggie McLeod is editor and publisher of Big River, an independent magazine about the Upper Mississippi River.

Copyright 2000, Big River

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