Louisville, KY -- The U.S. Army Corps of Engineers Louisville District has nearly completed conducting preliminary subsurface explorations at J.Edward Roush and Salamonie dams. The work began in the fall of Fiscal Year 2007 with an exploratory drilling and testing program.
Because of the geological similarities underlying the Salamonie and Roush Dams to the Mississinewa Dam, the Corps is conducting this drilling inspection. Through its Dam Safety program, the Army Corps of Engineers has observed seepage areas at the Roush and Salamonie dam projects at higher pool events. Although dams typically “seep,” the additional seepage areas at higher pools, and similar geologic formations to the nearby Mississinewa dam, warrant closer evaluation of the current subsurface conditions to verify the nature of this increased seepage.
The exploration programs consist of drilling small diameter holes into the ground and retrieving soil and rock samples for future lab testing. Additional instrumentation to detect water levels within the dam embankment are also being installed. These samples and test results will be used to perform further engineering evaluations and compared to existing and new instrumentation data.
The Louisville District annually inspects all its district reservoir dams. A more intensive team inspection occurs every five years through its Dam Safety program. Through these on-going inspections and evaluations of instrumentation readings within the dams, Salamonie and Roush lakes have received funding for further subsurface exploration and study. Field work has been completed at J.Edward Roush Lake, and the Salamonie Lake dam investigation exploration will continue for another week or two. Visitors to the area may have observed equipment on the dam used to take subsurface borings. Prudent management of these dams includes an increase in field and instrument monitoring during higher pools when additional seepage areas have been observed at these sites.
Samplings from the explorations are expected to be complete during the spring of 2007 with additional engineering evaluations to follow. Periodic updates will be released as study information becomes available.