The safety of our visitors, employees and our neighbors is our top priority at Crab Orchard National Wildlife Refuge. As a result of massive flooding, erosion and decay

Learn more about climate change. We have re-evaluated our existing infrastructure management planning and will be fully draining Little Grassy Lake starting this month.

Out of an abundance of caution, the U.S. Fish and Wildlife Service has determined that a proactive approach and utilization of this public resource is necessary to protect communities downstream. The goal of this decision is to minimize future impacts to Little Grassy Lake Dam and Crab Orchard Lake Dam. The Crab Orchard Lake Dam gates are also damaged, which could be further impacted by a failure of the spillway at Little Grassy Lake. Given that Little Grassy Lake was built upstream of Crab Orchard Lake, if the dam at Little Grassy Lake fails, this series of dams could trigger a cascade of infrastructure failures, resulting in the loss of life and property in downstream Carbondale, Illinois would lead communities in the surrounding area.

“These proactive measures are aimed at keeping everyone as safe as possible as we are concerned about the current state of the refuge’s aging infrastructure,” said Deb Beck, Midwest Infrastructure Management Division of the National Wildlife Refuge System.

Additionally, the refuge is in the early stages of what is expected to be a two-year process to assess and remediate the Little Grassy Lake Dam and Spillway. This is in coordination with the U.S. Army Corps of Engineers St. Louis District as part of the formal Little Grassy Lake Dam Modification Study, which began September 10, 2024. This project will continue under this new drainage management strategy given the increased risk and public safety concerns.

Draining the lake during dam rehabilitation will help address concerns about the current status of a compromised spillway should it be activated by extreme weather events. Proactively reducing water levels reduces the likelihood of a dam failure until repairs can be planned and completed

Learn more about structure.

The Little Grassy Lake Dam and spillway structure on the refuge are aging beyond their designed lifespan. The dam, built in 1942, is currently operating under an emergency plan because a recent inspection discovered problems in the spillway. Little Grassy Lake spans 1,000 acres and is one of three reservoirs with critically endangered dams within the refuge that require repair. All three reservoirs are critical to fish and wildlife, outdoor recreation, and the region’s socioeconomic vitality.

In addition to completely draining the reservoir, the plan is to leave the outlet gate open in the meantime. This allows all incoming water to pass through more safely without causing water to build up again.

We will continue to keep visitors, concessionaires and the local community updated as mining progresses through the winter months. Please visit our refuge website for the latest information.

For more information, please feel free to contact the refuge’s headquarters at 618-997-3344 or email the team at [email protected]. If you have any questions, you can also write to the following address: Refuge Manager, 8588 Route 148, Marion, Il 62959.