 | 09/11/2011 | | Riveted Steel | Crack in the penstock | Penstock rupture | Flow from the leak was about 10 gpm. |
| 04/19/2011 | Landslide | Canal | Canal failure due to a landslide | Canal failure as a result of a landlside. | Damage occurred on private property. |
| 05/02/2011 | Erosion | Riveted Steel | Penstock saddle displacement | Scouring and movement of the penstock saddles | Penstock was submerged and generation was halted. |
| 03/31/2011 | Rockfall | | Canal flume was damaged due to a rock fall. | Canal flume was damaged due to a rock fall. | There was leaking from the flume, but no erosion occurred. |
| 04/08/2011 | Precipitation | Steel | Sections of the penstock separated. | Sections of the penstock separated. | Minor erosion occurred and the penstock saddles moved significantly. |
| 04/01/1933 | | Concrete | Penstock rupture | Concrete monolith penstock and tunnel under dam ruptured. | Powerhouse inoperative. |
| 05/14/1962 | Penstock Dewatering | | Penstock collapse | Penstock collapsed when dewatered | None |
| 08/14/1974 | Penstock Dewatering | Wood | Penstock collapse | Collapse of wood-stave pipeline during dewatering operation. | Flow of silt into river. Rendered plant inoperable. |
| 01/28/1980 | | Steel | Penstock rupture | Riveted joints ruptured on steel pipe penstocks. | Minor erosion of slope. |
| 02/28/1980 | Valve Failure | | Penstock ruptured due to malfunction of a valve | Pressure regulator and bypass valves on penstock malfunctioned causing rupture of penstock. | Significant erosion and debris into powerhouse. |
