Innovation Spring 2026

A fish-friendly solution While flood protection was the primary driver, the project also addressed long standing ecological issues. For example, the original diversion structure acted as a barrier to fish movement, preventing upstream passage due to high water velocities through the original gates. The upgraded design incorporates two gates calibrated to allow fish passage at specific flow conditions, along with a dedicated fish pool that provides resting habitat after fish burst through higher velocity sections. The fish-friendly components were developed through close collaboration with biologists, environmental consultants, and Indigenous partners. “That fish pool basically … provides them with a resting area,” Malekian said, adding that biologists consulted for the project explained that fish moving upstream expend a lot of energy and need rest to continue their journeys. One of Malekian’s proudest moments from the project was witnessing a fish burst through the designed gate and reach the fish pool; the previous structure blocked fish from going upstream. “That was so refreshing – to see that your work actually had a great impact on not only fish, but also the habitat upstream,” he said. Beyond the fish pool, the project also incorporated riffles, floodplains, and large woody debris upstream of the diversion structure to improve habitat quality. Lessons learned One of the key takeaways from this work was the importance of timing. “Fish passages must be incorporated early in the design,” Malekian emphasized. “Environmental features are best to be integrated early in the process than be added at a later date.” For Malekian, the Mill Creek project

A dedicated fish pool provides a resting area for fish after they have plunged through the gate. P hoto : C ourtesy of CIMA+.

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Spring 2026

Innovation