Client Projects
Client Projects
Client Projects
Client Projects
Print this page

Electron Flume Mortality Study
Puget Sound Energy

Bellevue, Washington


The Electron hydroelectric project includes a 10-mile wooden flume, supplying water to two, 22-MW turbines. The flume was last rebuilt in 1985, with laminated wood floor and sidewalls and wooden supports. This study included an evaluation of the condition of the flume, and a projection of its remaining economic life.

The condition assessment was based on a health index of sampled sections. It included the distribution of health index for the wooden support structures and for the flume box, estimated remaining life from a technical perspective, and recommend maintenance and life extension measures.

The second task was to perform a probabilistic and economic analysis of the remaining life of the flume, including the expected cost from the risk of future failures. Failure rates of the flume and supports were projected using the historical rates for the current flume as well as the previous flume. This analysis quantified the incremental costs and benefits of various strategies of replacement, rehabilitation, and run-to-failure. Sensitivity analyses were performed in order to test the results against changes in failure probability, current condition, and discount rate. The economic analysis provided optimized schedules for interventions, such as rehabilitation or upgrade; optimum rate of replacement for the support structures; and projected future streams of capital costs, O&M, and risk-cost.

Date Completed: 2005

Relevant Highlights
Integrated condition and risk to develop optimized plan. Used statistical sampling to limit data collection effort. Developed custom failure projections.
© 2014 BIS Consulting LLC · Site by HELIX