Portland District team wins dam safety excellence award

Portland District’s Spillway Gate Reliability Team has been called upon to address a variety of issues, including buckling of end frames and beams, frozen trunnion pins, failed and frayed wire ropes, and failed electrical relays and limit switches. (Corps of Engineers photo)

Portland District’s Spillway Gate Reliability Team has been called upon to address a variety of issues, including buckling of end frames and beams, frozen trunnion pins, failed and frayed wire ropes, and failed electrical relays and limit switches. (Corps of Engineers photo)

By Scott Clemans, Public Affairs Office

Portland District’s Spillway Gate Reliability Team has been named the 2013 U.S. Army Corps of Engineers’ Dam Safety Team of Excellence.

The award recognizes the team members for their role in executing a $41 million (so far) spillway gate rehabilitation program to improve dam and public safety. It also honors their contribution to advancing dam safety within Northwestern Division and the Corps overall.

Portland District Dam Safety Officer Lance Helwig and Dam Safety Program Manager Matt Craig accepted the award from Corps Special Assistant for Dam and Levee Safety Eric Halpin and Dam Safety Program Manager Barbara Schuelke Aug. 27 at the Corps’ 2014 Dam Safety Officer Workshop in St. Louis, Mo.

Portland District Dam Safety Officer Lance Helwig (left) and Dam Safety Program Manager Matt Craig (second from left) accepted the 2013 U.S. Army Corps of Engineers’ Dam Safety Team of Excellence award from Corps Special Assistant for Dam and Levee Safety Eric Halpin and Dam Safety Program Manager Barbara Schuelke Aug. 27 at the Corps’ 2014 Dam Safety Officer Workshop in St. Louis, Missouri. (Corps of Engineers photo)

Portland District Dam Safety Officer Lance Helwig (left) and Dam Safety Program Manager Matt Craig (second from left) accepted the 2013 U.S. Army Corps of Engineers’ Dam Safety Team of Excellence award from Corps Special Assistant for Dam and Levee Safety Eric Halpin and Dam Safety Program Manager Barbara Schuelke Aug. 27 at the Corps’ 2014 Dam Safety Officer Workshop in St. Louis, Missouri. (Corps of Engineers photo)

Portland District started to find problems with many of its dams’ spillway gates in 2008. While designed and constructed to the standards of the day, time and increased use of the gates to meet downriver fish passage and water temperature requirements have led to degradation of mechanical and electrical systems.

Inspections discovered a variety of issues, including buckling of end frames and beams, frozen trunnion pins, failed and frayed wire ropes, and failed electrical relays and limit switches.

The bottom line is that some of these gates may not operate properly when water levels are high and placing significant pressure on them. This may result in a gate failing to open when desired, or becoming stuck in the open position when attempting to close it. This would limit or perhaps even compromise our ability to control water releases from that dam.

Immediate action was required. The challenge facing the Spillway Gate Reliability Team was enormous. Portland District’s 108 spillway gates range from 34 to 78 years old, with the majority well over 50.

The multi-disciplinary team started by evaluating risks by river systems and specific dams, and absorbing design guidance and knowledge that has evolved from field experiences like the 1995 Folsom Dam gate failure. The team also studied and adopted industry welding and fabrication improvements. This work provided the foundation for developing a “worst first” prioritization of repairs and improvements.

The prioritization effort led to early replacement or repair of critical components at Lookout Point, Dexter, Fall Creek and Hills Creek dams, which reduced but did not completely eliminate the risk of uncontrolled releases from those gates.

With the worst of the risk mitigated, the team began planning and executing more comprehensive rehabilitation projects. Foster Dam’s spillway gates and associated systems were rehabilitated in 2009, followed by Dexter and Big Cliff dams.

On-site work to rehabilitate Fall Creek and Green Peter dams’ spillway gates and associated systems started in September.

The team was recognized for its flexibility and innovation in overcoming a variety of challenges, including meeting downriver flow targets during construction, continuing flood control operations, and accommodating road access for wildland fire fighting and other critical needs.

For example, many of our dams do not have stop logs to dewater the gates for repair. To overcome this deficiency, the team designed a unique bracing method that used the radial portion of the gate as a bulkhead that transferred water pressure to the spillway bay piers instead of the gates’ arms, allowing the arms to be removed and either strengthened or replaced.

The team also developed an operations inspection and testing policy that has become the basis for a Northwestern Division policy, further improving gate reliability across the region.

During design and construction of these rehabilitations, team members have developed significant expertise in welding, fabrication, self-lubricated bushings, machinery design and controls, and other specialties.  This expertise hasn’t gone unnoticed – Portland District has been requested to support similar efforts in Baltimore, Omaha, Sacramento and Los Angeles districts.

In short, Portland District’s Spillway Gate Reliability Team has made substantial contributions to dam and public safety not only in the Willamette Valley, but throughout the nation. They are bringing the U.S. Army Corps of Engineers’ vision to life: “Engineering solutions for our Nation’s toughest challenges.”