Shoreline Woody Structures

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To nurture ecological health, our shorelines need submerged trunks, limbs, branches, roots, and wood fragments within shallow waters. With the exception of state forest and preserved lands, relatively few natural, partially submerged woody structures exist on Lake Leelanau. Learn how to plan a shoreline woody structure for your property and why now is the time to do it.

Woody Structures Wanted

Participants at LLLA’s recent Shoreline Restoration Field Day were able to observe ‘close up’ two erosion-control projects (using grading, coir log placements, and stone) and one buffer zone creation (planted extensively with native shoreline plants).  These examples on South Lake Leelanau demonstrated various approaches for shoreline protection and enhancement of near-water terrestrial habitats.

When terrestrial and aquatic elements are managed in tandem, shoreline erosion and suspension of sediments are reduced. In particular, the aquatic habitat is improved where there is more shade cover and substrates for insects and algae. Moreover, the woody structures can lead to increased fish colonization (shelter, feeding, nesting, and spawning habitat), and probable usage by turtles, birds, and other wildlife.

LLLA encourages the intentional placement of woody structures in and on the shoreline to restore aquatic habitats. However, this requires the homeowner riparian (or contractor) to obtain an EGLE permit. The following is our guide to getting started.

Figure 1. A natural shoreline “turtle log” on the South Lake today where a fallen tree has resulted in a favorable geometry for shallow water shade and aquatic habitat
Figure 1. A natural shoreline “turtle log” on the South Lake today where a fallen tree has resulted in a favorable geometry for shallow water shade and aquatic habitat

Plan Your Project

To get started, read more from EGLE about woody structures here and here. Consider how such a project might work on your shoreline, taking into account the steepness of the bank, water depth (it should be approximately 2-ft to 5-ft over much of the structure’s length), distance to seasonal docks/hoists and swimming areas, and local navigation routes. Establish a conceptual placement that works with adjacent neighbors and avoids nearby property lines.

While these projects can be accomplished by a homeowner, landscape and shoreline restoration firms have the experience and the machinery that may be necessary for the work.

Determine the Source of Trees

Will trees come from your own land or elsewhere? What tree species are available? Tree diameters of 6-in to 10-in are common, singly or grouped together. Recently live trees are preferred, with recommended lengths around 20-ft to 40-ft long. How will the selected trees be moved and readied for placement at the shoreline? Trunks and branches can be left “as is” or trimmed to improve placement objectives.

Placement

Figure 2 illustrates a few pointers for installation of woody structures. Note the placement of the tree’s larger end on shoreline stone above the Ordinary High Water Mark.  Determination of this shoreline mark is made on a parcel-by-parcel basis.

Figure 2. Placement of shoreline woody structures
Figure 2. Placement of shoreline woody structures

Secure Your Project

EGLE requires the permitted woody structures to be secured. Project site variations in wind and wave energy, as well as ice heaves, may call for a robust design so the structure will remain in place for the long term. Design suggestions include the use of wire cable (1/4-in to 3/8-in diameter) looped around the butt end of the tree(s) and secured with cable clamps. The shoreline end can be secured to a live tree trunk or sturdy metal or wood anchors on shore. Some projects secure the cable to deep-set steel or wooden fence posts. Where lateral movement of grouped trees is a concern, a ¼-in cable can be connected at selected intersections of the logs.

Depending on the density of the trees used, temporary weights may be necessary for the first year to keep them submerged.

Figure 3. This is the first shoreline woody structure to be permitted for Lake Leelanau. South Lake, May 2024.
Figure 3. This is the first shoreline woody structure to be permitted for Lake Leelanau. South Lake, May 2024.

Draft a Permit Application

The EGLE permit process is all online and easy to use. It allows one to readily fill in blanks, pause, and later continue along the section-by-section steps toward full completion and submittal.

Some of the steps towards beginning a draft application are:

  • create an MiEnviro Portal account (the entryway for developing a permit application);
  • review how to begin a digital EGLE/USACE Joint Permit Application (JPA) for Inland Lakes and Streams;
  • examine the entire blank application, noting definitions of terms, check box options, required reference materials and drawings to be attached, and a nominal fee payment necessary for the actual submittal.

EGLE offers an optional ‘pre-application meeting’ (by telephone or in-person) to explore options, get explanations, and do a ‘dry run’ of the draft application.

Learn more

Shoreline woody structures are desirable and healthy for Lake Leelanau. Think about using your winter months to plan a shoreline improvement project. Contact our Shoreline Ambassadors at [email protected] for further guidance. We're here to help!

For more background information, click here to read one of our past articles on woody structures.

If you enjoyed this publication, view more of our articles on lakeleelanau.org.
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