Prince Rupert Woodworth Dam wins prestigious engineering awards

The City of Prince Rupert’s Woodworth Dam Project won big with the Lieutenant Governor’s Award and the Award of Excellence at the Association of Consulting Engineering Companies BC (ACEC-BC) Awards ceremony on April 13.

The Lieutenant Governor of British Columbia, Janet Austin presented BBA (formerly Austin Engineering), who was the lead engineering consultant on the monumental dam construction project, with the award, which is given to only one recipient each year.

The Woodworth Dam Project was tendered to BBA by the City of Prince Rupert after years under boil water notices to help optimize the redesign and secure the project. The dam was aging, supply lines needed to be replaced and the city was seeking funding for the multiyear project in order to secure a primary water source, BBA stated.

“By undertaking a comprehensive value engineering review, our team members optimized the initial Woodworth Dam design and significantly decreased the project budget by 17 per cent using an innovative 3D printing approach,” BBA stated in its project information.

The 3D printing approach allowed the team to compare several models with various dams being printed, riverbeds were CNC routed and they were all tested in hydraulic flumes to confirm flow characteristics, BBA stated.

“The dam site is located seven kilometres from a tidal barge landing, which could only be accessed to load and unload equipment no more than three hours per day during high tide. All equipment, concrete, rock, aggregate and other items from the project needed to be delivered by barge to this landing and then trucked seven kilometres up a single-lane forestry service road,” the submission reads.

The 3D engineering plans reduced rock anchor quality by 40 per cent, concrete volume by 25 per cent and rock excavation volume by 18 per cent. It also assisted with environmental solutions such as re-using foundation rock which saved 500 trips up and down the service road and reduced rock excavation, limiting the amount of debris entering the stream.

Since Prince Rupert is known for its significantly heavy rainfalls, care was taken to predict and allow for future changes in flow regimes within the river system as a result of climate change, BBA explained. The spillway capacity was oversized to allow for future flood flows and demands.

For a number of years, the City of Prince Rupert had been subject to boil water notices due to turbidity levels of its secondary water source Shawatlan Lake and the completion of the project has ended those occurrences while balancing economic and environmental goals.

“Now water can be taken directly from the Woodworth Reservoir and piped via HDPE pipeline down and across the harbours, entering the city’s water system. This is a major improvement in quality of life for the community,” BBA said.

The project also received the Award of Excellence in the Municipal and Civil Infrastructure category, which recognizes technical excellence and innovation in consulting engineering.

The ACEC-BC has been recognizing the “outstanding accomplishments” of consulting engineering companies across the province for more than 32 years, their webpage states.

“The award recipients – individuals and organizations – are a testament to the consulting engineering profession, to the ACEC-BC membership’s shared belief we are better together, and the association’s deep-rooted commitment to the professional community and the communities where we work.”