Innovation Spring 2026

“

Treating these types of projects should be a long-term adaptation investment rather than just capital upgrades. Sit down and ask yourself, ‘OK, in 10 years from now, what

could happen?’ Dr. Ali Malekian, P.Eng., Senior Project Manager, CIMA+

”

the system over time. The same water level sensors that trigger gate movement and trash removal also provide long-term performance data. “Year after year after year, they’ll be able to get more data and calibrate the system,” Malekian said. This data feeds into the city’s Supervisory Control and Data Acquisition (SCADA) system, enabling operators to compare real-world performance against design assumptions. Importantly, the system was not designed to be static. “The system setting can be adjusted as conditions change,” Malekian explained. “Things might change in five, 10, 20 years from now – and [city workers] have the capability to open, close, and play with [the gates] at any time during any sort of water flow event to reduce the risk of overtopping upstream and downstream of the diversion structure.” Advanced data modelling also played a large role in the structure’s design. The CIMA+ project team relied on advanced hydraulic modelling to understand how the system would behave under increasingly extreme flow conditions. CIMA+ used HECRAS, a hydraulic modelling program developed by the U.S. Army Corps of Engineers, to simulate one-dimensional and two-dimensional flow through the creek and diversion structure. Given the unique geometry and operational complexity of the site, the modelling work was crosschecked using additional software. Malekian noted that the team used FLOW-3D, a computational fluid dynamics (CFD) platform, to analyze the diversion structure itself.

Clearing debris was a constant concern before the trash rake was installed in the new system. P hoto : C ourtesy of CIMA+.

“I’ve seen pictures of city staff going in, bending over the guard rails and taking the debris out,” Malekian said. “This is something completely unsafe for the workers.” The solution was a redesigned diversion system featuring an inclined trash rack and an automated trash rake. The new inclined rack allows water to pass underneath while debris accumulates in a controlled way. Sensors monitor water levels, triggering the trash rake to clear debris automatically. “Whenever the water level hits a threshold, the trash rake starts,” Malekian explained, describing the rake system as a boom. “The trash rake starts taking the trash off of the trash rack…which makes sure that the trash rack is always clean.” By clearing debris in real time and eliminating the need for emergency overnight manual intervention, the system greatly reduces the risk of overtopping and downstream flooding while improving worker safety. With this system, “excess water is diverted into Mission Creek even under high-flow conditions,” Malekian said. Monitoring and adaptive control Beyond improving day-to-day operations, automation also allows the city to actively manage and recalibrate

32

Spring 2026

Innovation