Recent events involving the operation of spillways for the Oroville Dam in California have brought renewed attention to potential failure modes associated with both concrete chute spillways and unlined spillways at dams. As a result, FERC has required detailed assessments of similar spillways to be completed this year at high and significant hazard dams. FERC identified specific dams within licensees’ inventories that need to receive a focused spillway assessment by December 31, 2017. In addition, FERC required a focused PFMA to be completed on these spillways either during our annual dam safety inspections or separately. A generic copy of the letter sent to these licensees is provided in the link below.
In addition, based on questions we have received from licensees regarding the detailed spillway assessments, FERC has developed a frequently asked questions document to aid in complying with this request. A link to that FAQ is provided below.