St. Louis River Restoration Initiative

Progress Update - February 2012

On Wednesday, February 15, crews from Marine Tech were finally able to begin the process of extracting over 200 derelict wooden pilings that cross the bay.Tops of pilings visible through ice

These pilings consist of spruce and tamarac logs from trees that took root in the late 1700's to early 1800's.  They were driven into the bay in the late 1800's where they supported a railroad trestle.  The rail line was abandoned a mere five years later. The pilings have remained in place for over 100 years.

The removal process requires heavy equipment, in this case a relatively large excavator which has been driven over the frozen bay.  The ice is cleared from around the pilings using the excavator's bucket.  Then, a vibratory, hydraulic gripper is attached to the excavator and the pulling process begins.

Using vibration and upward pull, the 35-40 foot long pilings are extracted one at a time.

Re-using the pilings

The pilings are remarkably intact, having been buried in mud for over 100 years.  While the quality of the timber used in these pilings is not furnitue-grade, we are evaluating their use for the observation platform and related boardwalk which will be constructed at a later date.Marine Tech crews removing pilings

About the Estuary

The St. Louis River Estuary — an unprecedented 12,000-acre wetland complex between Duluth, Minnesota and Superior Wisconsin — is critical to the life-cycle of millions of fish, waterfowl, raptors and song birds in the Lake Superior region.  The Estuary is also home to the nation’s busiest fresh water harbor and mid-America’s gateway to global trade.  It is a treasure to more than a quarter million residents and 3.5 million tourists who live, work and play along its shores.

Aerial view of St. Louis River estuary, Duluth harbor upper right

However, in 1987, after years of closed beaches and fish consumption advisories due to untreated wastewater, industrial pollution and habitat loss, the Estuary was listed as one of 43 Areas of Concern (AOC) in the Great Lakes.  It is the largest of all the AOCs, and also is the most biologically productive. Along with this designation came a mandate to once again make the beaches swimmable, the fish edible and the water drinkable.

Restoring the estuary at Radio Tower Bay

After more than 20 years of research and preparation it's time to recover the Estuary’s rich legacy by restoring critical near-shore habitat in this wetland complex. One of the real-world projects where the Land Trust is working is Radio Tower Bay.

From the late 1800's through the early 1900's, Radio Tower Bay was the site of an historic sawmilling operation constructed on pilings over the water.  The sawmill was constructed on pilings driven into the bottom of the estuary.  Much of the sawdust and slabwood from the millThe bay floor is covered with 4 - 8 feet of sawmill debris.Sawmill debris (4 - 8 feet thick) visible during low water levelsin 2011.ing operation ended up on the bottom of the bay, greatly reducing the quality of underwater habitat for fish and rendering the bay nearly useless for recreational value.

The Land Trust is working to restore this 40-acre bay by removing the concrete pylons, the derelict pilings and four to eight feet of sawmill debris from the bottom. We'll be re-vegetating the benthic (bottom layer) for better aquatic productivity and establishing a fishing pier so kids and adults have better recreational access to the water. This project provides jobs, improves the fishing industry, provides recreational access, and ultimately, cleans the water. And all this is done in concert with a working, productive harbor.