Snake River: Warning to River Users: Pool Fluctuations Predicted in Lower Granite Navigation Pool

Warning to River Users: Pool Fluctuations Predicted in Lower Granite Navigation Pool

Date Sent: 6/9/2022

All:

Predicted storm events will cause fluctuations in the Lower Granite Navigation Pool starting Friday 10 June, and likely lasting through Friday 17 June 2022.  River flows in the area are predicted to exceed 200kcfs at times during this period, starting Saturday 11 June.

The Lower Granite pool is currently holding at approximately 736’ elevation at the Clearwater/Snake Confluence.  Because a pool elevation of more than 738’ will cause flooding in Lewiston, water managers will begin lowering the Lower Granite pool tonight, 9 June, to make room for the predicted river inflow.  Consequently, river users may encounter a pool elevation at the Confluence of less than 736’ at times.  River users are cautioned to monitor the Reservoir Control Center website at:
Northwestern Division > CRWM > Water Control Data > Project Data (army.mil)    Select “Lower Granite – Hourly” for the most up to date data, and observe the column “LWSI Gage Elevation” to get the latest pool elevation at the Confluence.

River users are also cautioned that during this period lock and dam operators may have limited ability to perform gate operations to facilitate safe spill to benefit vessels entering and exiting the navigation locks, due to high river flows.  Vessel operators should exercise appropriate caution in the vicinity of the locks.

I trust this information will help keep all river users safe!

Thank you much

//signed//

 

Kenny Koebberling
Navigation Business Line Manager
Jackson Levee Project Manager
509-527-7364