“Immortal River” choking on sediment

Flooding impact ... The Army Road boat launch ramp area east of New Albin was still under considerable water in late July. The ramp opened up for the first time this year August 2. Photo courtesy of Captain Ted Peck.

by Captain Ted Peck

The irreversible and profound impact of the Mississippi River flood of 2019 became evident just prior to the Labor Day weekend. The “Immortal River” is a never-ending source of subtle nuances and clues which can translate into amazing fishing results for those who can decipher what the river is whispering as it eases through the Driftless Area towards perpetual mingling with the Gulf of Mexico.

Work as a full-time fishing guide on Pool 9 for the past 18 years and nearly a half-century before that on Pool 13 nearly 190 miles downriver standing on the shoulders of four prior generations of “River Rats” has created an enigmatic relationship only the river’s soul could understand.

Pool 9 of the Mississippi River finally dropped down to what casual observers might consider normal late summer pool levels by the first week in August. Navigation in the backwaters and running sloughs is challenging with low water levels which come this time of year, about six weeks prior to the linear hay field of sand grass which typically chokes the channel come mid-September.

In years past, shallow water back in sloughs and cuts away from the channel meant rocks on wingdams and closing dams to fulfill the U.S. Army Corps of Engineers (USACE) mission of maintaining a nine-foot channel for navigation were exposed.

But this year the rocks are still one to three feet beneath the river’s surface. This situation defied common sense to one who is so familiar with the river.

A call to USACE public affairs coordinator George Stringham brought both clarity and shock to what the river was whispering.

“Flow rate is still above 50 percent of normal levels for late summer,” Stringham said. “The reason for low water levels in backwaters and sloughs beyond the channel  is because sediment drops out of the water column in areas of reduced current. Many thousands of tons of sediment were left behind beyond the channel as the river pushed through the Driftless Area”.

Exceptionally high water conditions since ice-out March 21 of this year prohibited access to the Army Road boat launch east of New Albin until August 2. Slow moving current in Minnesota Slough and the surrounding flood plain coupled with over five months of high water provided ideal conditions to deposit thousands of tons of sediment in once vibrant backwaters in that slough and in similar habitats throughout Pool 9.

This rich sediment has enabled amazing aquatic plant growth to occur in the flood plain and river islands where about 60 percent of the tree canopy in the river bottoms is silver maple trees.

“Silver maples can tolerate ‘wet feet’ for a long time,” USACE forester Randy Urich said. “Water up in the trees for a month or more is not uncommon on the flood plain of the Upper Mississippi.”

But there is a limit on the tolerance of even the most water friendly, non-aquatic plants. Five full months with several feet of trunk under water is proving to be too much for many of these mature trees, some of which sprouted from seed shortly after the 33 lock and dam systems which span the river from St. Paul, MN to St. Louis, MO were placed in the mid 1930s, changing plant ecology in the bottomland forever.

“Some areas on the river, like the islands and flood plain in Minnesota Slough between New Albin and Lock & Dam 8 just east of Reno, MN, are now experiencing mature tree loss in excess of 50 percent,” Urich explained. “The good news is thousands and thousands of seeds have been deposited which will become over canopy growth in the future.”

That future is not likely the future of anybody walking the planet today. With fewer healthy mature trees to hold soil in the floodplain, erosion will be exacerbated in the not so distant future. With sediment decreasing both fish habitat and carrying capacity of flood water, flooding in the Driftless Area is anticipated to be both more frequent and severe in the decades ahead.

While he was a kid coming of age on the “Immortal River” back in the early 1960s, this author’s family had a pontoon boat tied up along the shoreline of a backwater known as Miller’s Lake just north of Savanna, IL on Pool 13. From this mooring it was possible to get out to the channel through at least four different routes. Today there is just one passage - which needs to have a narrow channel dredged to access the channel almost every summer.

In the early 1980s until the mid 1990s this author used to spend a lot of time fishing and guiding on Pool 11 around Guttenberg. By the late ‘90s navigation in the backwaters at “normal” summer pool levels became tough - bordering on impossible - due to siltation.

Just two years ago the rocks of many wingdams and closing dams would poke out a good foot above the water at “normal summer pool” here on Pool 9. Not anymore.   Technically, the flow is still 50 percent above normal for Labor Day weekend - at least on the main channel.

Beyond the channel, the river is changed forever, and for the worse. Essentially, the river is like a 200-mile long septic drain field which failed years ago near this author’s childhood home with the impact of that continued siltation further likened to water now backing up in the basement with every flooding flush in far northeast Iowa - and calling a plumber is not an option.

Captain Ted Peck has been guiding on the Mississippi River for over 30 years,working on Pool 9 since 2001. He is also Pool 9 Editor for Big River magazine.

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