Forest Preserve District of Cook County
Dam Maintenance Projects
Hey and Associates, Inc. was retained by the FPDCC in to prepare design plans and permitting for maintenance repairs to 13 existing District dams. The dams range from Class III earthen embankments with outlet culverts to Class II impounding structures such as the approximately eight-foot high and 140-foot long Tampier Lake Dam, a dam at a crucial fisheries management facility for the District where stock fish are reared for stocking in other District lakes.
Hey inspected each of the 13 dams, and compared our findings to previous inspections performed by the USACE. Following inspection, Hey developed plans to repair dam components in need of maintenance or replacement for the 13 dams, including cost opinions. Measures included replacement of outlet pipes and works, repair of earthen embankments, recapping of the concrete dam at Tampier Lake, stabilization and restoration of outlet channels, replacement of outlet grates, and repair of concrete structures. Working with the District, Hey assisted in prioritizing the projects to best utilize available funding. Five of the dams were bid in late 2014, with construction taking place in 2015 and 2016.
Hey prepared permit submittals and responses for required permitting for the dams. Permitting included USACE Regional Permits, IDNR-Office of Water Resources Dam (IDNR-OWR) Safety Permits, Soil and Water Conservation District approvals for soil erosion and sediment control, threatened and endangered species coordination, and Illinois Historic Preservation Association consultation. Dam Safety permitting included preparation of Operation and Maintenance Plans, Emergency Action Plans, and in the case of Tampier Lake, a dam breach-wave hydraulic analysis.