Clarke Bellinger Stormwater Management Pond retrofit
The City is undertaking the retrofit of the Clarke Bellinger Stormwater Management Pond. The construction will involve the decommissioning of active monitoring and level/flow control systems and conversion of the facility into a passive stormwater pond.
The Clarke Bellinger Stormwater Management Facility originally constructed in 1982 and upgraded in 1993 will be undergoing a retrofit to decommission aging infrastructure and convert the facility to a passive stormwater facility.
The existing pond is configured to provide active level / flow control through the use of an overshot gate which allows the water level to be actively controlled to promote settlement of particulate and contaminant removal in the pond. Ultraviolet (UV) treatment of effluent water from the pond is performed to reduce levels of E.coli, and other similar bacteria in the water and is highly correlated with bird and animal waste flushed into storm sewers during rain events.
The pond has been actively sampled for decades for both the stormwater inflows and outflows from the facility with treatment levels being calculated. Stormwater ponds are typically installed prior to widescale development within the catchment area, to provide treatment of runoff from building sites before it can enter creeks, streams and rivers and have harmful impacts to fish, wildlife and the environment. As developed areas mature, and developable land decreases, the requirement for stormwater treatment can also change.
In early 2021, the City completed a performance assessment of the Clarke Bellinger Stormwater Management Facility to evaluate the impact of the pond operating in passive mode. When the pond was operated in passive mode without UV treatment, water quality monitoring showed consistently “Good” results per the Canadian Council of Ministers of the Environment water quality index. Monitoring during this period also demonstrated that water quality objectives continued to be met for TSS and E. coli, the target parameters identified in the ponds’ Certificate of Approval. These results from the performance assessment support the proposed decommissioning of the automated overshot gate and UV treatment system. The proposed conversion of the Clarke Bellinger Facility to a passive stormwater management facility was raised with the Ministry of the Environment, Conservation and Parks (MECP), with no concerns being generated with the proposed approach.
The proposed changes will result in the City’s stormwater management group being able to reduce operating and maintenance costs at the Clarke Bellinger Facility and to redirect limited resources to targeted initiatives within the City that have a higher impact on protecting the environment.
Construction scope:
Decommission UV (ultraviolet) Treatment Building, conversion to a storage building
Removal of all inlet buildings and associated hydro poles west of Leikin Drive
Removal of active overshot gate structure at outlet, and creation of a maintenance pad for debris removal
Modification of existing passive outlet structure, and upgrade of railings, deck and access
Paving near UV (ultraviolet) Treatment Building, down the slope
Minor pathway granular repairs at various locations
Project timing:
Design: January 2025 to early fall 2026
Construction Start: Late fall 2026
Construction Completion: Early fall 2027
Visit the project website↗ for more information and project updates.