All fast track projects are inherently difficult, but an emergency flood control contract to protect a nuclear reactor complex became most challenging due to stringent security measures and the physical challenges of building a structure in the bottom of a steep canyon.


In June of 2000, a controlled burn in the Jemez Mountains surrounding the U.S. Department of Energy’s Los Alamos National Laboratory (LANL) in New Mexico went awry, destroying 48,000 acres of forest and the natural flood protection it provided for the highly sensitive LANL facilities at the bottom of Pajarito Canyon on the cusp of the rainy season. The situation was a potential crisis in the making, and averting a nuclear disaster became the highest priority of the U.S. Army Corps of Engineers.


To expedite the process, the Corps entered an emergency design-build agreement with Sundt, and we mobilized within 24 hours. To access the site, Sundt and our subcontractors were required to provide three days’ notice and all personnel had to pass a security clearance. The team built a temporary road leading to the canyon edge; from there workers accessed the construction site by rappelling down a steep trail.


The primary structure required 67,000 cubic yards of roller-compacted concrete to build a 390-foot-wide, 66-foot-high flood control structure that is 93 feet thick at its base and anchored 50 feet deep. The $7.9 million structure is the centerpiece of $13 million in emergency flood control work Sundt performed in the area, all designed and completed within 90 days.


U.S. Army Corps of Engineers


Los Alamos Emergency Flood Control Structure