Page - 67 - in Book of Full Papers - Symposium Hydro Engineering

 Engineering consulting firms: GEI Consultants, HDR Engineering, Stantec, AECOM, David Ford Consulting Engineers, Northwest Hydraulic Consultants, Lettis Consultants International, Vali Cooper & Associates, and RMA Group.  United States Army Corps of Engineers and United States Bureau of Reclamation. In addition to the engineering professionals directly integrated into the OER team, several specialty consultants were added to the OER team to provide specific engineering services:  Brierley Associates to provide expert peer review evaluations of rock slope stability and planned stabilization of eroded and over-steepened rock slopes along the FCO Spillway chute channel,  BGC Engineering USA to provide scour evaluations of the rock materials on the Emergency Spillway,  REVEY Associates, Inc. and EROCK Associates to provide engineering designs and oversight for explosive blasting excavation and demolition, and Utah State University to provide physical hydraulic modeling for the redesign of the FCO chute. Over 100 individuals were eventually integrated into the OER team, with most initially assigned to work together in spaces provided in the California Natural Resources Building in Sacramento, California. Many members of the team were later relocated, as needed, to Oroville Dam during field investigations and during construction later in 2017. Team members commonly worked 12+ hours each day, 6 to 7 days a week. Key points in the timeline were as follows: o Oroville Incident and Emergency: initiated February 7, 2017 o OER Design Phase: March – July 2017 o OER Mobilization Phase: April – May 2017 o OER Construction Phase 1: May – November 2017 2.3. PROJECT OBJECTIVES The original design intent of the FCO Spillway chute was to safely pass flood flows ranging up to about 7390 m3/s (261,000 ft3/s) without using the Emergency Spillway. During larger floods, the Emergency Spillway would also be used to pass flood flows for events up to the Probable Maximum Flood (PMF), a very rare event that had an average recurrence interval commonly on the order of 10,000 years. The total discharge from the FCO Spillway chute and the Emergency Spillway during the PMF event would be about 19000 m3/s (671,000 ft3/s), with the FCO Spillway chute being used to pass flows up to 8500 m3/s (300,000 ft3/s) and the Emergency Spillway being used to pass about 10500 m3/s (371,000 ft3). The purpose of being able to pass the PMF event is to prevent the embankment dam from being overtopped and failing during this extreme design 67