Engineering review finds Shawnee Twin Lake dam in fair-to-satisfactory condition; staff debate costs to make kayak launch ADA-compliant

Freese & Nichols engineers summarized a final report on the Shawnee Twin Lake dam and recommended a limited set of repairs and additional studies while saying they found no immediate dam-safety issues.

Colin Young, civil engineer with Freese & Nichols, told the City Commission that the firm conducted independent site inspections, topographic and geotechnical reviews and a spillway-capacity analysis; the report accounted for prior consultant work and peer review by the U.S. Army Corps of Engineers Tulsa District and the Oklahoma Water Resources Board (OWRB). "We didn't see any immediate dam safety concerns," Young said, adding that the team recommended targeted repairs and future studies rather than large-scale reconstruction.

Why it matters: Twin Lake is a municipal water-resource asset and the lake's dam is categorized under state dam safety rules. The report's recommendations affect both public safety planning (update of breach inundation mapping and the city's emergency action plan) and near-term maintenance budgets.

Key findings and recommendations:

- Condition ratings: The report used FEMA-adopted descriptors (satisfactory, fair, poor, unsatisfactory). The dam's crest and core components were generally rated satisfactory, while the upstream and downstream slopes received fair ratings because of localized sloughing, mismatched…