After a year-long investigation, the Bureau of Reclamation attributed the failure to a design flaw: the Corps of Engineers, which designed the dam, did not consider trunnion friction (at the pin-hub interface) in the gate analyses. While this is true, this was one of five identical service gates that operated under the same circumstances for nearly 40 years without problems being observed. This suggests that the failure resulted from a condition that changed over time; specifically, there was a gradual increase in the coefficient of friction at the pin-hub interface. While one would expect maintenance frequency to increase as a gate ages, Reclamation decreased the frequency of regular maintenance and lubrication over time due to budget constraints. In addition, the lubricant used by Reclamation did not conform to the Corps' original design specifications; it was a new, environmentally-friendly lubricant that was not sufficiently waterproof, allowing water to enter the pin-hub interface and cause the corrosion that resulted in increased friction.