A 65 foot crack was found on Wanapum Dam, upstream from the Hanford Nuclear Site. KAPP reports:
The Grant County Utility District has gone to work since the crack was discovered, dropping the reservoir about 25 feet.
Alleviating the pressure helped stabilize the spillways and allowed the crack to close by nearly an inch as of this morning.
However, the drop in water level can be seen all along the riverside.
People living in the area will have to get used to the sight for some time, crews will need to keep water levels this low in order to begin their assessment of the crack.
"Now we're moving into the next phase, which is to investigate it further, identify a cause, and begin looking into some of those short term and long term potential fixes," said Grant PUD representative Thomas Stredwick.
As the article notes, this disaster will likely do serious economic damage to the region, since this is a prime boating area for people and outsiders. The area is closed for boating and could be through the summer. People will likely take their dollars elsewhere.
The problem is that no contingency plans for fixing a crack of this nature were ever put in place for this dam even though it was reasonable to assume that a crack of this nature was a possibility. Emergency planners have an obligation to prepare for contingency plans of all kinds; there was no excuse to be caught flat-footed in this manner. Northwest Public Radio:
Dam operators are struggling to find a solution for a major underwater crack in the Wanapum Dam. It spans the Columbia River in central Washington near Vantage.And Fiber One News:
It remains unknown how the crack can be fixed. Allen said. He doesn’t know when the work on a solution will be completed.According to the Associated Press, the utility does not believe that there is a threat for people downstream.
"Say this section were to fail completely," spokesman Tom Stredwick said Monday. "The remainder of the spillway would remain intact and with the current amount of water in the river, the water through that section of the dam would still be normal for this time of year."The article notes that a big difficulty will be in managing the river flow. While the electric utility says that they will still be able to sell electricity, if the problem gets worse, then they might have to buy electricity elsewhere, possibly forcing them to raise rates.
Boise Public Radio quotes Stredwick in more detail:
"A spillway is the portion of the dam that allows water to "spill" past the dam as opposed to running through the turbines. The spillway consists of multiple, independent structural sections that support the spillway gates. Each of Wanapum Dam's 12 spillway gates are capable of passing roughly 80,000 cubic feet of water per second based on current river conditions. In a worst case scenario, if one of the spillway sections failed, the remainder of the spillways and the main dam structure would remain intact. Under current conditions, the amount of water that would flow through this section of the dam would be within the range of normal river conditions."The question is, what if another spillway gate were to fail?
The Seattle Times says that even in the best case scenario, this could affect the entire Columbia River system.
Even if the dam doesn’t fail, the significance of the damage is likely to require extensive repairs and that, too, could impact the entire Columbia River system.
“All these dams coordinate to generate energy on a regional scope,” Stedwick said. “If Wanapum is impacted, that has impacts on dams up stream as well as below.”
But Kevin Wingert, a BPA spokesman, said the immediate impact would be an increase in flow from Priest Rapids Dam downstream, which would temporarily exceed the low flows needed to protect chinook salmon redds (nesting holes) through the Hanford Reach area.While none of us hope that the worst case scenario happens, we must always determine what the worst case scenario could be and how peoples' lives might be effected. The first question is, if the entire dam fails, would there be a threat to Hanford? And the second question is, would there be a threat to people living downstream?
He expected flows to return to normal once the drawdown was completed.