The US Bureau of Reclamation has released a draft environmental assessment for its proposed dam safety project at Kachess Dam in Kittitas County, Washington state, with two actions analysed.
It says work is needed at the project as voids have formed along the outlet works due to erosion from seepage following years of operation. In the first option, USBR is proposing to reduce long-term performance risks by constructing an access road; preparing the site to develop staging areas to support construction and long-term maintenance; extend and line the conduit; and install a filter and stabilization berm. There is also a no action alternative proposed in the EA.
The proposed modifications are expected to address issues important to the long-term functionality of the structure, but USBR stresses that there is no immediate safety threat at the dam and confirms that it is rigorously monitored for any changes in performance.
Comments are now invited on the project up to 30 March 2022. The draft EA is available at https://www.usbr.gov/pn/programs/sod/kachess/index.html.