Demanding Hydroelectric Project Relied on Strong Teamwork, Efficient Design Changes

The project team collaborated with diligence and inventive ideas to plan construction and review design constructability to safely move materials and equipment down the face of the dam. Meticulous preplanning for construction was critical for everything from bringing in heavy equipment and materials and accessing the tunnel, to hauling drinking water and Honeybucket facilities. IMCO’s team collaborated and planned for safety and logistics in innovative ways, submitting concepts for review and approval by the District. They utilized a large crane and pully system as a material and equipment conveyance system to the portal of the tunnel.    

IMCO laser-scanned the completed tunnel to model the fabricated steel pipe for custom “fit-up spools.” This approach allowed us to accelerate the fabrication of the steel pipe so only a few spools were on hold until completion of the tunnel. The laser scan data helped ensure proper off-site fabrication of the custom fit-up spools. This saved the project significant time in the schedule. 

Our approach integrates technology and Virtual Design Construction into the preconstruction and throughout construction to the extent that best serves the needs of our projects.

The construction team identified that there was an unknown site condition that could have had major impacts to the project schedule. Significant redesign was required in the middle of the project. The team quickly and drastically change course while keeping the project on schedule. IMCO, Redpath, and Snohomish PUD worked together to manage the changes in a manner that did not disrupt the client’s schedule or budget. The angle of the outfall piping was changed, and structures were added in support of the change. The team worked through the changes and associated cost-increases. The client was very satisfied with the process and the outcome.

Safety risks were greatly heightened because of the tight access and remote location. The remote site and limited amount of communication resources increased the potential for safety risks. Personnel access was limited to the use of a steep-pitch stairway 14 flights down the face of the dam. Adverse weather conditions with substantial snow in the winter further increased the challenge and risk. The project experienced all seasons to the extreme. Beginning in the summer 2017, crews were faced with very dry conditions and concerns related to forest fires. During the fall and winter months, several feet of snow fell, causing shut downs and delays associated with snow removal, safety, and access to equipment and materials. 

The IMCO team never missed a critical deadline and planned and executed with great attention to detail to ensure the client’s operations were maintained. The client has a high level of trust in the project leaders, who listened and showed great patience with the entire process.  

“IMCO showed diligence and strong commitment to high performance throughout the project. The team was committed to working through challenges. Kirt and Taggart (IMCO’s Superintendent and Project Manager) were driven to address the many concerns that we were faced with throughout the course of the is project, I appreciate their dedication,” said Eric Schneider, PE, Snohomish County PUD #1 Principal Engineer.