Dam C at the Lakes of the Four Seasons in Crown Point, Indiana, had suffered severe cracks in its concrete revetment. A result of the cracks was severe erosion and this led to an Indiana Department of Environmental Management (IDEM) required repair. The Lakes of the Four Seasons hired REAS to assess the situation and come up with the best solution. Several repair options where considered and the best one for this project was to use pre-formed, pore filled, concrete block mats. Using these mats would eliminate the need to remove all the broken concrete (and potentially cause disturbance to the structure of the dam) as well as prevent material from the damaged structure and/or the repair to migrate into the lake. Future maintence costs would be minimal also.
Approval for the repair was obtained from the DNR and the project commenced. Ground penetrating radar was used to examine the ground beneath the existing concrete to check for voids. None were found. Existing broken concrete was leveled, geotextile fabric and PVC geomembrane installed over it and then the concrete mats were placed.
Trenched areas were backfilled, erosion control matting installed in disturbed areas and the repair of the dam's revetment was complete.
On a future note... REAS has recently been asked to proceed with more engineering work for the Lakes of the Four Seasons. These projects include repair of the intake tower as well as repair of the pipe leading from the dam to the intake.