The Mitchell City Council approved a $98,413 contract with Houston Engineering to complete a 50% probable maximum flood assessment, breach analysis and updates to the city's emergency preparedness plan for Lake Mitchell.

City staff said the study is required by the state Department of Agriculture and Natural Resources as part of the city's plan to open a hole in the spillway and to move forward with the lake project. City staff recommended awarding the scope of work, which includes hydrology, spillway-capacity evaluation, dam routing, breach mapping and an incremental damage analysis if required.

City staff member Schrader told the council the contract covers project management and technical work and that the work is mostly desktop analysis. "The scope of work includes project management, reviewing and developing hydrology for the lake and spillway, spillway capacity evaluation, dam routing, breach analysis and mapping, emergency preparedness plan updates," Schrader said. He also said the incremental damage analysis would be required only if the 50% PMF analysis shows it is necessary.

Schrader and other staff said the study could be completed quickly if there are no unforeseen delays. "As fast as they think it could be completed in two months," Schrader said when describing the consultant's timeline. The city also noted that much of the initial work is desktop analysis and that on-site activity may come later, depending on findings.

Council members asked whether the lead consultant, Mike Sotak, is licensed in South Dakota; Schrader said he believed Sotak is a registered engineer in the state.

The council approved the agreement by voice vote after a second; no roll-call tally was read into the record.

Next steps: staff will begin the study and, when results are available, present options and timelines to the council for any decisions about drawing down the lake or beginning construction work on the spillway.