Green Bay Botanical Garden Dredging and Dam Reconstruction
Robert E. Lee & Associates performed a Dam Inspection on the privately owned dam located on the Northeast Wisconsin Technical College Campus in Green Bay, Wisconsin. The inspection revealed that a number of improvements were required to bring the structure into compliance with current design standards. In addition, the water quality of the impoundment has severely degraded over recent years due to sediment accumulation. The improvement to the dam required the impoundment be completely drawn down creating an opportunity to dredge the impoundment. REL was retained for the design, permitting, and construction services to rehabilitate the dam and dredge the impoundment. To complete the dredging design, a bathymetric survey was performed of the impoundment and a depth-to-refusal survey was performed. Samples were collected during the depth-to-refusal for laboratory analysis. The test revealed the sediment contained high levels of lead, arsenic, as well as DDT and its breakdown component DDE. The depth-to-refusal survey indicated approximately 5,200 cubic yards would require disposal to an approved solid waste facility. The Brown County Bayport Dredge Material Rehandling Facility was approved by the Wisconsin Department of Natural Resources (WDNR) as a suitable disposal location. REL prepared an engineering report of the dam design and dredging, which was submitted to the WDNR and U.S. Army Corps of Engineers for approval.