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.

Timeline

Summer 2019: Engineering and coastal design drawings

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

Fall/Winter 2020*: Anticipated permit approval; begin construction of breakwater system and seawall

Summer 2021*: Complete construction of breakwater system and seawall

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



Current Problems

Lakebed Erosion and High Water Levels

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 its 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 erosion and record high water levels

Shoreline Erosion

High waves near shore and record high water levels have caused irreversible damage to Lloyd’s shoreline. In the past 15 years, more than 20 feet of bluff has been lost along the south shoreline. In the past three years, severe bluff erosion has caused more than ten trees to fall.

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

Extensive bluff erosion has caused tree loss along south end

Along Lloyd’s north shoreline, high waves and high water levels have caused beach erosion.

Beach erosion on north end summer 2019

Beach erosion on north end summer 2019

Loss of Useable Beach

Since 2005, rising water levels have caused loss of a useable beach and non-motorized boat storage on the south end. In the summer of 2019, record high water levels were reached.

Lloyd Beach summer 2005

Lloyd Beach summer 2019



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.

Conceptual rendering of proposed breakwater system at low lake levels

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.

Conceptual 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.

Conceptual rendering of proposed breakwater system showing gap

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.

Conceptual rendering of proposed breakwater system at low 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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