AYRES - DELTON AMENDMENT FOR UNDERWATER INSPECTION

The Agreement for Professional Services made as of January 26, 2022 between Sauk County (OWNER) and Ayres Associates Inc, 700 Pilgrim Way, Suite 180, Green Bay, WI 54304 (CONSULTANT) is hereby amended as set forth below.

REASON FOR AMENDMENT
While completing the scope of work described in the January 26, 2022 Agreement, CONSULTANT became aware of a potentially significant scour hole at the toe of Delton Dam’s spillway, which likely caused the failure of the fishing platform immediately downstream. Given the unprotected toe at the base of the spillway, which extends all the way across the river channel, additional scour and spillway undermining may also be present. These issues, if present and left unaddressed, could pose a significant threat to the safety of the dam. Therefore, a full underwater inspection of the area immediately downstream of the dam is warranted. With the information obtained from this inspection, CONSULTANT will be able to prepare a conceptual repair plan to address the collapsed fishing platform and potential scour and undermining of the spillway. Currently, not enough information is available to develop a repair plan with a reasonable level of confidence.
To date, the $20,000 not-to-exceed limit of the January 26, 2022 Agreement has been expended. Work completed to date includes two visits to the dam to inspect the site and take GoPro videos, coordination with the OWNER and the Wisconsin Department of Natural Resources (WDNR), assistance with preparing a Municipal Dam Grant application, preparation of conceptual repair options and cost estimates, and research related to the dam’s construction and past flood events.