Greenbrier Creek Dam is an earthen embankment impounding a reservoir that supplies water to Mt. Sterling, Kentucky. The embankment was constructed in the early 1960s and has been raised twice since original construction. Recurring downstream slope instability has been documented since 2015.
In August 2022, slope failure areas encompassed approximately half of the crest width at two locations along the dam. The progressing failure mechanism prompted rapid incident response measures, daily visual observations by the City, coordination with state regulatory officials, and review of a large volume of historical information to identify possible root causes and potential failure modes (PFMs).
Since then, multiple exploratory methods have been used, and an instrumentation monitoring program has been installed to provide near-real-time data and alerts related to the behavior of the dam. The incident response efforts are ongoing, and design of interim risk reduction measures is in progress.