Officials with the Army Corps of Engineers' St. Paul office will analyze the safety of the Ford dam on the Mississippi River, after it was classified in the second-highest category as a safety risk.
The 92-year-old dam between Minneapolis and St. Paul was among the more than 600 dams nationwide that the Corps has inspected during the last year.
Engineers in the St. Paul office have not found any evidence that the dam has a seepage problem, according to Safety Program Manager Dave Rydeen.
But he said inspectors flagged it as a potential problem because they didn't find a seepage analysis in any of the office's documents.
"If they couldn't find something in the stack of drawings and analysis that would show something to be OK, they would flag it as a potential problem, and that's what this was," said Rydeen, adding that the last analysis was probably done in the 1980s during the dam's last rehabilitation.
The new analysis will look at whether water is seeping under the concrete dam. Rydeen said some seepage is normal, but too much could be a potential risk.
"If you started eroding material out from under the structure, then the structure could become unstable," Rydeen said.
A three-person team in the district office will conduct the analysis, which should be completed by the end of summer. It's expected to cost about $20,000.