Generating electricity since 1967, Wells Dam is an 840-megawatt hydroelectric facility located on the Columbia River, spanning from Douglas County to Chelan County in Washington. The facility is owned and operated by Douglas County Public Utility District (DCPUD). DCPUD selected Schnabel to perform the eleventh FERC Part 12D Dam Safety Inspection and Potential Failure Mode Analysis (PFMA) Update for the project.
An external board of consultants (BOC) was formed in 2018 to aid DCPUD in addressing significant dam safety concerns related to seismic stability and internal erosion of the east embankment. During the course of the Part 12D services, we also performed a Level 2 Periodic Risk Assessment to help inform the BOC and DCPUD of the primary risk drivers for the dam and allow DCPUD to prioritize its efforts.
DCPUD subsequently retained us to develop a subsurface exploration program to characterize the embankment and foundation in order to inform the planned engineering analyses related to these risk drivers. We were also retained by DCPUD for other dam safety services, including a Dam Safety Surveillance and Monitoring Program update, Dam Safety Surveillance and Monitoring Report preparation, 3-D Geologic Model development, filter compatibility analysis, and safety assessment of groundwater pumping wells.