In 2012 AECOM was hired to help the City of West Kelowna develop a plan to integrate the water systems within their boundaries. Five legacy water systems developed prior to the City’s formation had an initial focus on conveying irrigation water then later potable water. After significant effort, a Master Water Plan (MWP) was finalized for the long-term implementation of compliant potable water to all the customers within the boundary.

The largest project within the MWP was the construction of the Rose Valley Water Treatment Plant (WTP) and the associated reconfiguration of the legacy water systems to create a single potable distribution system that meets a municipal standard. This is a critical step as the City moves to upgrading their infrastructure to meet current regulations and standards.

With a construction cost of $75 M, the Rose Valley WTP is the largest project in the City’s history. AECOM was engaged in 2017 as the prime consultant for the conceptual design, detailed design and construction services. This new plant provides coagulation, dissolved air flotation (DAF) clarification, filtration and disinfection consisting of UV radiation and chlorination. The initial treatment facility design flow is 70 ML/d with the ability to expand to 115 ML/d in the future.

Prior to the completion of the Rose Valley WTP, 60% of residents of the City didn’t have access to potable drinking water. Raw water was only treated with chlorine and distributed. Toxic algal blooms in the water supply led to seasonal water advisories.

This project met client goals including addressing solutions for the future community growth, changing climates, preserving the environment, minimizing the disturbance of natural land for the new infrastructure and optimizing the use of energy during construction and the future facility operation. The project was completed on-budget during construction challenges such as Covid, a wildfire and numerous supply chain interruptions.

AECOM developed several preliminary design options with the process selection being coagulation, DAF clarification, and filtration, followed with UV radiation and chlorination for disinfection. Filter column pilot testing to confirm loading rates and different media designs in additional to benchtop testing was completed. This work verified the process selection assumptions for the completion of the design. With the treatment process needs confirmed, the design advanced with a focus on operational ease, energy efficiency and adaptability for changing future conditions.

Algae toxicity was a concern raised repeatedly by Interior Health during the development of the design. AECOM work closely with the approving agency to ensure the needs of Interior Health and the other approving agency were achieved. Collaboration with all the local and senior government approving agencies was completed throughout the project.

The civil early works contract was completed during 2020 and consisted of earthworks and buried utilities. Main contract construction began in April 2021 and is complete. Despite construction setbacks due to Covid, supply chain issues, and a wildfire, distribution of potable water began in November 2023. Once the new treatment facility was put on-line the existing legacy pump sources could be abandoned allowing all the residents in the legacy Lakeview Irrigation District to benefit from gravity, treated water from the Rose Valley Water Treatment Plant.

By taking a holistic approach to the new water treatment plant, with a focus on the long-term sustainability, the residents of the City of West Kelowna realized the following benefits:

• A site selection and design that preserved the area’s high environmental value.
• Enhancement of Faulkner Creek.
• Energy optimization and long-term sustainability
• By late December 2023, all area residents were receiving potable water.
• Project was completed within the overall $75 M budget.