Iowa's Mississippi River Islands Are Vanishing. A $40M Project Is Rebuilding Them

Islands and backwaters along the Mississippi River near Guttenberg, Iowa, have been quietly disappearing for years. Erosion, flooding, wind, and waves have worn away their shorelines. Now, a major federal restoration effort is fighting back, using dredged river sand to rebuild lost habitat and protect what remains.

The Lower Pool 10 Habitat Rehabilitation and Enhancement Project, part of the U.S. Army Corps of Engineers' Upper Mississippi River Restoration Program, is designed to protect and restore about 630 acres of riverine, backwater, and floodplain habitat. The work is happening on the Iowa side of the navigation channel, about a mile upstream from Lock and Dam 10 in Guttenberg, within the Upper Mississippi River National Wildlife and Fish Refuge.

Why the islands are disappearing

Natural islands in this stretch of the river have been worn down over time by wave action, main-channel currents, and repeated flood events. The erosion has reduced wetlands, stripped away aquatic vegetation, and eliminated the shallow, sheltered areas that fish and wildlife depend on.

River currents, boat traffic, and floods have all contributed to the damage. As islands vanish, backwater areas become more exposed to wind and waves. Sediment builds up in places that once provided valuable habitat. The loss is not just about missing land. Islands shape how water moves through the river system. They shelter backwaters from strong currents, creating calm, shallow zones where aquatic plants and wildlife can thrive.

Turning dredged sand into new islands

One of the most striking features of this project is how it reuses material from the river itself. The Corps is using nearly 300,000 cubic yards of sand dredged from the Mississippi River to maintain navigation channels for barges. Instead of dumping that material elsewhere, crews are using it to build island foundations.

Construction equipment, including skid loaders and bulldozers, is working on the islands. The sand comes from the bottom of the river, where it was removed to keep the channel deep enough for commercial traffic. The project's technical documents show the islands are built with a granular sand base, topped with finer material. Rock protection is being installed around existing islands to prevent further erosion. Rock sills and mounds are planned in selected spots to reduce wave and wind forces and direct water flow into backwater areas.

What the project includes

The selected plan is not just about building new islands. It combines several types of work:

• Constructing new islands
• Protecting existing shorelines
• Building rock mounds and sills
• Dredging habitat areas

Together, these measures are meant to improve the quality and stability of the river environment. The project targets about 630 acres of habitat within a roughly 1,000-acre side-channel and island complex. The acreage figure refers to the habitat expected to benefit from the restoration, not the entire physical site.

Construction is underway in stages

The restoration is being delivered in phases across different island and backwater complexes. Stage 1 focuses on the southern islands in South Ferry Slough. The Corps awarded a $7.5 million construction contract for that stage in 2024, and work began in 2025.

Stage 3 targets the McMillan Island complex between river miles 618 and 619. In May 2026, the Corps awarded a $5.5 million contract for this stage. It includes island creation, shoreline protection, main-channel dredging, and dredging of overwintering backwater areas. Construction was expected to begin in summer 2026 and continue into late 2027.

The Corps lists the project's anticipated construction cost at $39.5 million. Completion is expected in 2030, though work on remaining stages depends on future appropriations from Congress.

Why this matters for Iowa's river ecosystem

The goal goes beyond rebuilding visible islands. Restoring them helps recreate the sheltered conditions that support wetlands, shallow water, and backwaters. These environments provide space for aquatic vegetation and offer habitat for fish and other wildlife. The Corps says the project is intended to improve ecosystem health and create better-quality habitat for native and desirable species.

This work is part of the broader Upper Mississippi River Restoration Program, a federal initiative authorized in 1986. The program combines habitat restoration with long-term monitoring of the river system. According to the Corps, more than 62 habitat projects benefiting approximately 120,000 acres have been completed throughout the program's history.

A restorative and preventative approach

For Lower Pool 10, the strategy is both restorative and preventative. The project rebuilds islands that have already been lost or severely eroded, while strengthening existing features so they can better withstand the forces that caused the damage in the first place.

The use of dredged sand also ties river navigation to habitat restoration. Material removed to keep the channel open for barges gets a second life within the river ecosystem, turning a maintenance necessity into a conservation asset.

For Iowans who live along the river, the project represents a long-term investment in a landscape that has shaped the region's economy and identity. The Mississippi River is not just a transportation corridor. It is also a living system, and this project is an attempt to keep it that way.

Frequently asked questions

Where is the Lower Pool 10 habitat project located?

The project is on the Iowa side of the Mississippi River navigation channel, about one mile upstream from Lock and Dam 10 in Guttenberg, Iowa. The site is part of the Upper Mississippi River National Wildlife and Fish Refuge.

How much is the project costing?

The Corps lists the anticipated construction cost at $39.5 million. Contracts awarded so far include $7.5 million for Stage 1 and $5.5 million for Stage 3.

When will the project be completed?

The project is expected to be completed in 2030, though construction of remaining stages depends on available federal appropriations.

How is dredged sand being used in the restoration?

Nearly 300,000 cubic yards of sand dredged from the Mississippi River for navigation is being used to build island foundations. This gives the dredged material a productive purpose within the river ecosystem.