1 Powerdale Damage Assessment November 14, 2006

2 Based on Provisional Data. Gaging equipment suffered some malfunction during this event so hydrograph likely does not resemble rising limb. USGS is in the process of reconstructing this event. 2 - Powerdale Flood Damage 11/9/2006

3 Silt at fish ladder Entrance to fish ladder Sorting facility fish return pipes 3 - Powerdale Flood Damage 11/9/2006

4 Fish ladder 4 - Powerdale Flood Damage 11/9/2006 Auxiliary fish ladder pump out of service

5 Sand traps full of sediment 5 - Powerdale Flood Damage 11/9/2006

6 Collapsed 10’ dia. wood stave flowline – 490’ 6 - Powerdale Flood Damage 11/9/2006

7 Steel flowline – 325’ – 170’ collapsed – 155’ slid north 5 inches failing foundations Walkway section lost downstream – location unknown Foundation washed ¼ mile downriver Flow 7 - Powerdale Flood Damage 11/9/2006

8 Collapsed steel flowline – 325’ requiring replacement 6 failed foundations Cracked supports (6 total) & slid pipe 170’ 155’ High water mark 8 - Powerdale Flood Damage 11/9/2006 Damaged Seawall

9 Cracked flowline foundations – 6 total Crack at cold joint 9 - Powerdale Flood Damage 11/9/2006

10 Sediment deposit at tailrace River Tailrace Sediment deposit 6’ - 10’ above normal 10 - Powerdale Flood Damage 11/9/2006

11 Powerhouse Switchyard Chemical Storage 11 - Powerdale Flood Damage 11/9/2006 Powerhouse Shop

12 Powerhouse Shop 12 - Powerdale Flood Damage 11/9/2006

Powerdale Flood Damage 11/12/2006 Former River Channel