A dam in Grandwood Park that had become increasingly unstable and failed in July 2017, sending water and fish into the yards of homes on the south side of Lake Park, has been replaced and reopened.
The Grandwood Park Park District, the Lake County Stormwater Management Commission and community residents celebrated the grand reopening of the Grandwood Park Lake Dam at a ribbon-cutting ceremony on Friday.
“In 2012, we started having a lot of problems with the dam. We had one flooding event after another, more damage and increasing issues,” Park District President Nancy Carlson said in a release announcing the dam’s reopening.
According to stormwater management officials, the dam was experiencing constant flooding and was in danger of collapse. It was declared a significant safety hazard, and steps were immediately taken to rehabilitate it.
Construction began in November. Officials said it “passed its first test with flying colors” last week as it handled recent rains and resulting floodwaters.
“When the project first began, the dam was ready to give way,” Lake County Board member Steve Carlson of Grandwood Park said Monday. “I would like to commend all of our partners who took immediate action to ensure this rehabilitation would take place.
“We are happy to say that this dam will help prevent flood damage in this community and will maintain the precious wildlife that live in this area.”
Coincidentally, the grand reopening ceremony for the dam occurred at the tail end of the recent flooding, and Carslon said that caused some water to flow onto the sidewalk leading to the dam.
But Carlson added that is the way it was designed, and the grading and rocks next to the sidewalk approaching the dam quickly absorbed the water back into the lake.
“It’s working just the way it was supposed to,” Carslon said.
The lake in Lake Park is fed by, and drains into, Mill Creek.
The dam was designed to increase control over high-water events, which will help minimize shoreline erosion caused by fluctuating water lines, officials said, adding that it also works as a flood hazard reduction by creating greater control of outflow.
“The Grandwood Park Dam rehabilitation project aligns with (the stormwater management commission’s) mission to improve water quality, reduce flood damages, and restore and enhance the natural drainage system,” Stormwater Management Commission Executive Director Mike Warner said in the release. “We were proud to be a part of it.”
The commission included the replacement of the dam in the Mill Creek watershed plan based on analysis of the dam structure and embankment, impact of the dam to surrounding residents and the region, Warner said.
The new dam configuration includes a concrete-enhanced primary spillway and an 80-foot stone armored secondary spillway, which directs overflow to a controlled area and a new, high-quality wetland area, he said.
During the Lake County flooding event in July 2017, the lake in Lake Park, which — to the chagrin of residents — had drained earlier that year due to a failed dam, took a huge step in the other direction when Mill Creek rose steadily until it overwhelmed the banks.
As a result, water began pouring over the lake’s southeastern banks, and for days ran over sidewalks, park lands and into the backyards and basements of area residents, as well as nearby streets.
