Considering the 2017 Oroville Dam Spillway incident, it’s clear that dam owners are tackling many complex challenges. The past year was replete with lessons learned, and along the way SAGE has been dedicated to the exploration and implementation of long-term solutions that advance the state of dam and levee safety practices. Northern California’s premier dam safety experts Dr. Faiz Makdisi, PE, D.GE, and Marc Ryan, PE, GE, along with Drew Kennedy, PG, CEG, and Darren Mack, PE, GE, are headed to the 2018 USSD Annual Conference in Miami, Florida, and look forward to advancing the conversation on dam safety.
During the fourth quarter of 2017, the team took part in 19 spillway inspections (including 8 Part 12D safety inspections), prepared 6 comprehensive focused spillway assessment reports, and 13 spillway inspection reports. They facilitated 18 spillway-focused PFMA workshops, including preparing summary reports for each workshop, and were advisors for 3 additional spillway-focused PFMA workshops. In the words of one Deputy Chief Dam Safety Engineer, “With much appreciation and gratitude, we thank you for this incredible team effort and collaboration on the Spillway Assessment Reports.”
With more than 39 years of specialized experience in geotechnical and earthquake engineering, Dr. Makdisi (together with the late Professor H.B. Seed) is widely known for the groundbreaking study “Makdisi and Seed,” and for the exploration, and evaluation of the seismic performance of earth and rockfill dams subjected to strong earthquake shaking. Makdisi serves on the Oroville Dam Spillway Board of Consultants tasked with reviewing and commenting on repairs to the damaged spillways.
Mr. Ryan has been working to advance the state of geotechnical dam safety for the past 20 years by studying dam safety and seismic retrofits in California, throughout the United States, and internationally. Most recently he was invited to give a talk to state and federal dam safety officials at a national Federal Energy Regulatory Commission dam safety training seminar. His topic was, “Development of Interim Reservoir Restrictions for Earth dams Subject to Large Seismic Deformations.”
Looking ahead, Mr. Ryan is focused on seizing opportunities to perform post-earthquake reconnaissance of earth dams. He states that observations of a dam’s performance under extreme loads is critical to understating the risks associated with building dams in earthquake country.
Mr. Mack, whose experience includes a broad mix of geotechnical engineering and civil/structural design, was heavily involved in several of the spillway inspections performed in 2017. In his opinion, “The Oroville Spillway incident was a game changer. The short-term flurry of activity to inspect and evaluate concrete spillways for high-hazard dams in California was just the beginning.”
Among his current projects, the design of seepage mitigation measures for a large, 145-year-old rockfill dam, places Mr. Mack at the table with state and federal regulators who are sifting through volumes of data for spillway inspections throughout California.
Mr. Kennedy, who is collaborating on a paper for the ASDSO 2018 conference discussing the performance of unlined spillways in granitic rock in the Sierra Nevada, was an integral part of the spillway inspections and PFMA sessions providing the engineering geologist’s perspective. According to Mr. Kennedy, “The impact of geology on dams became apparent following the St. Francis Dam failure in 1928, and the recent events at Oroville are a reminder of the need to properly characterize the foundation conditions during design and construction, and to have engineering geologists involved in dam safety inspections and PFMA sessions.” Mr. Kennedy provides engineering geology services to numerous dam owners, and he recently led the spillway inspection team for New Don Pedro Dam, which is the ninth tallest dam in the United States.
From current practices to examples from case histories, the team has collaborated on numerous projects together. They agree that the most interesting projects are those that include a combination of detective work to understand the construction of aging facilities, and modern engineering to understand how a structure, well into its design life, might perform during “the big one” – whether it be a storm or earthquake
If you plan to attend the 2018 USSD conference in Miami, stop by booth #209 and join the discussion.