Shoreline Stabilization

The Park District will be conducting shoreline stabilization measures at Lloyd Beach that include a new breakwater system and new steel seawall along the south and north end of the beach. Other improvements to be completed in conjunction with these measures include new queuing space at the boat launch, reviewing the stormwater discharge system, and adding new ADA beach access ramps.

For detailed information, click the measure below.

Timeline

June/July 2019: Engineering and coastal design drawings (in process)

August 2019*: Submit permit (adding any structures to the shoreline requires an extensive permitting process by several governing authorities; the permitting process is very rigorous and can take six to 18 months)

Winter 2021*: Permit approval

Spring through Winter 2021*: Construction

*Dates are estimated and may change depending on the length of the permitting process.



Shoreline Loss

Throughout history, Lake Michigan’s water levels follow a pattern of rising and falling. These fluctuations combined with increased wave action cause the shoreline to slowly erode. At Lloyd, this process has been especially detrimental due to lakebed downcutting — the erosion of the cohesive clay material that makes up the lakebed.Unlike sand, this material can’t be replenished and loss is permanent. As it erodes, the lakebed profile becomes steeper and the water near the shoreline becomes deeper. Deeper water near the shoreline causes waves to be larger and the shoreline to erode at a faster rate.

High waves that continuously impact Lloyd due to lakebed downcutting

This has caused irreversible damage to Lloyd’s shoreline. The south end of Lloyd has been impacted the most because it has no protection from the waves. In the past 15 years, more than 20 feet of bluff has been lost. In the past three years, severe bluff erosion has caused more than ten trees to fall. The north end of Lloyd has been less impacted due to the protection it receives from the boat launch structure and steel seawall.

South end of bluff summer 2005 (no visible erosion)

South end of bluff summer 2019 (visible erosion approximately 8 feet high)



Breakwater System

If no action is taken, the beach and bluff at Lloyd will continue to disappear. To slow this process, breakwaters need to installed. Breakwaters work in several ways:

  • Breaking or intercepting the waves to dissipate wave energy before reaching the shoreline, which decreases erosion and makes the beach safer
  • Creating a basin that keeps sand in so a usable beach is maintained during high and low water levels

The proposed breakwaters at Lloyd will be made of piles of stone in the lake. During average lake levels, approximately five feet of stone will be visible above the lake’s surface. At today’s lake levels about two feet of stone would be visible. This is high enough to protect the beach during periods of high waves but low enough that the view of the horizon from the beach will not be impeded.

587′ foot high breakwater at Sunrise Beach, 2.5′ higher than proposed

587′ foot high breakwater at Sunrise Beach, 2.5′ higher than proposed

The breakwater system includes a structure at the south end, in the middle and at the north end. A portion of the south end breakwater will start on the beach. It will include built-in stairs allowing patrons to easily traverse it while walking along the beach.

Rendering of new breakwater system approved by the Park Board in 2019

A 140 foot to 150 foot gap will exist between the breakwaters, ample space for motorized and non-motorized boaters to safely pass through.

Together the breakwater structures will effectively reduce the wave action near the shoreline to protect the beach and bluff from erosion, protect the boathouse, and make the water safer for patrons. Over time, the beach will begin to build up sand allowing us to maintain a usable sandy beach during periods of low and high lake levels.



Steel Seawall

Currently, Lloyd has a steel seawall that runs along the foundation of the boat house and extends north.

Existing steel seawall along and north of boathouse (summer 2019)

Without this structure, the boathouse would have been destroyed during the record high lake levels and wave action that has impacted Lloyd since 2013.

Existing steel seawall breaking high waves to protect boathouse and north end of beach (summer 2019)

This seawall will be expanded to the south end and further on the north end to provide additional protection for the bluff and shoreline, and serve as a foundation for the ADA ramps and future phased improvements as outlined in the Winnetka Waterfront 2030 Plan.


 
 
 
 


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