| Dam Name | Wanapum |
| Incident Date | 7/3/2007 |
| Country | United States |
| State/Province | Washington |
| Dam Height (m) | 28.3 |
| Uncontrolled Release of the Reservoir | No |
| Dam Type | Concrete; Rockfill; Gravity |
| Detailed Dam Type | |
| Incident Type | |
| Incident Description | In late July 2007, Grant County PUD (GCPUD) maintenance crews installed the floating bulkhead in tainter gate 1 at Wanapum dam. The gate was opened approximately one foot to discharge the leakage water and keep the space between the bulkhead and the gate from filling with water. On August 3, 2007, during routine maintenance the crew discovered the bent side plate on the left bank gate hoist chain on gate 1. Photo 1 is a picture of this bent side plate. It is the outside plate between roller pin number 41 and 42. See Drawing No. 2750534 for the location of pin 41 and the side plate. Maintenance crews removed the gate drain plugs and lowered the gate down onto its sealing surface on Monday August 6, 2007. It should be noted that after the gate was lowered and the load was removed from the chain, the bent side plate returned to its original position to such a degree that it became difficult to determine which plate was bent using visual methods. Maintenance crews removed the entire left bank hoist chain and replaced it with a spare chain on August 17, 2007. Crews also replaced the right bank hoist chain. |
| High Level Failure Mode | |
| Lessons Learned | |
| Initiating Event | Equipment Failure |
| Initiating Event Description | |
| Structures/Components | |
| Failure Mode Description | |
| Emergency Action Plan Implemented | No |
| Consequences | Consequence Data Unavailable |
| Geographic Coordinates - Decimal Degrees | 46.8731, -119.9703 |
| Normal Reservoir Storage (m3): | |
| Crest Elevation (m) |