Project to slow erosion at Illinois Beach State Park to cost $74 million

[February 27, 2023]  By Zeta Cross | The Center Square contributor

(The Center Square) – About $74 million in taxpayer dollars aims to slow down the impact of erosion at Illinois Beach State Park. The project is the largest capital project in the Department of Natural Resources history.

The park in Lake County at the state’s northern border is Illinois’ last beach-ridge shoreline along Lake Michigan. Swales sustain marshlands where migrating birds return year after year. The wetlands are home to plants and animals, many of them threatened species.

Some of the older beach ridges at Illinois Beach State Park date back 3,000 years.

“It is a very unique ecosystem, especially in Illinois where so much of our lakefront is fully developed,” coastal geologist Robin Mattheus told The Center Square.

The trouble is that the beach’s shoreline is eroding. In some spots the sand is disappearing at a rate of 100 feet a year. From 2012-2020, the park lost the equivalent of 50,000 dump trucks full of sand, Mattheus said.

State IDNR officials have committed to work at halting the erosion at Illinois State Beach and protecting the wetlands and ecosystem that is threatened.

In that effort, Gov. J.B. Pritzker announced $74 million in funding for two projects that will construct man-made islands and 22 submerged rubble reef breakwaters that will act like speed bumps to slow down the impact of the waves. It is the largest capital project in IDNR history.

The northern part of the Illinois Beach State Park is a promontory that juts out into the water and is particularly vulnerable to winter ice and waves.

“The lake can get quite rough,” Mattheus said.

With more than 400 kilometers of open lake to the north/northeast, “given the right wind conditions, we can have waves that are up to 20 feet in height,” he said.

Fluctuating lake levels are even more damaging to the shoreline than the ice and waves, he said. Depending on wind, storms and runoff, lake levels can rise and fall by as much as 2 meters, Mattheus said. As the waters fluctuate, the sand goes with it.

Two hundred and fifty thousand tons of rock fill will be used to construct the rubble reefs. The core of the reef ridges is made of smaller stones. Larger stones on the outside create an armor layer to protect the core of the reef from wave attack. Not only do the rubble reefs slow down waves, they are also designed as habitat for fish. Three reefs that were installed last year are already home to numerous fish.

The Illinois Capital Development Board is providing the funding as part of the $45 billion Rebuild Illinois Capital Plan, which funds port projects and state transportation.

The Army Corp of Engineers, the Environmental Protection Agency and the National Oceanic and Atmospheric Agency will participate in the effort. Healthy Port Futures, The Great Lake Protections Fund and the Illinois State Geological Survey are also working on the projects.