Control structure is major gap in dam cost estimates
An apple to apples comparison of engineering estimates for the replacement of the Chelsea Lake Dam showed that while some items were missed in the original estimate, the bulk of the cost difference is in the water level control structure.
Members of the Taylor County Forestry committee last month voted to hire Oakridge Engineering to do an independent review of both the preliminary estimate from Flambeau Engineering and the Ayres Associates engineering estimate for the dam project. The Ayres project costs were significantly higher than those in the Flambeau design.
On Friday, committee members received the side-by-side comparison showing that while many of the costs areas were similar, the Flambeau Engineering estimate had not included filter expenses to prevent silt contamination of the lake water. Even taking that out, of both estimates Oakridge prepared its own estimate based on the specifications given to Flambeau and came back with a report that the cost for replacing what is currently there with an identical structure would be about $90,000, about double what Flambeau’s estimate was with major cost differences in mobilization, site access and dewatering.