WCW26

A railyard and logistics centre Staged Master Drainage Plan (SMDP) outlines the stormwater management strategy for a 536‑hectare industrial development in southern Alberta. Prepared to meet strict local authority guidelines in a closed basin, the plan aims to manage post‑development runoff, protect retained Crown‑claimed wetlands, and integrate local and regional drainage infrastructure. The SMDP emphasizes adaptive management and long‑term monitoring to address uncertainties in groundwater–wetland interactions and ensure ongoing regulatory and environmental compliance.
The site consists primarily of cultivated land with flat topography and numerous wetlands. Geotechnical and groundwater investigations identified variable till layers and shallow bedrock, with groundwater generally flowing toward wetlands and exhibiting seasonal fluctuations. These conditions informed the drainage design and wetland protection approach.
Stormwater management is centered on nine wet stormwater management facilities (SWMFs) designed to provide sediment control and water quality treatment, exceeding the local authority requirement for 85% total suspended solids removal. Several facilities are positioned to support wetland hydrology and include provisions for direct pumping where required. A regional stormwater trunk system conveys controlled outflows to an open channel and is sized to accommodate both onsite and upstream catchments.
Development is planned in six phases, with each phase extending the trunk system and constructing associated infrastructure. Due to the absence of feasible overland emergency spill routes, the trunk system is designed with increased capacity to manage extreme storm events.
Hydrologic modeling using PCSWMM shows reduced infiltration and groundwater recharge and increased surface runoff following development. To mitigate impacts on wetland hydroperiods, adaptive management measures are recommended, including seasonal or year‑round pumping and potential supplemental groundwater baseflow.

The Lauderdale neighbourhood in Edmonton ranked as one of the higher priority flood risk neighbourhoods in EPCOR’s SIRP basin ranking system. The neighbourhood is partially separated with some dedicated storm sewers, but also portions of combined sewers with lower level of service that tend to exhibit drainage issues during intense rainfall. Stantec Consulting was retained by EPCOR to implement a flood mitigation dry pond and storm sewer upgrades in the neighbourhood to reduce the flood risk and improve the level of service for the drainage system. Starting as a concept design evaluation, the project continued through to a design phase and now implementation with construction starting in late 2025. Some unique challenges arose during the project including the assessment of a complex drainage network using a 2D hydraulic model, special design considerations for implementing a stormwater management facility in Edmonton’s largest fully fenced off-leash dog park, and a portion of dual-micro tunneling for deep sanitary and storm sewer installation. This presentation will showcase the unique challenges, creative solutions and lessons learned of this complex drainage upgrade in a sensitive area.

Urban stormwater management is increasingly required to balance flood mitigation, water quality improvement, and sustainable water use. The Cornerstone Phase 1 Storm Pond P project in northeast Calgary demonstrates how stormwater reuse can be integrated into conventional wet pond design to support both landscape irrigation and wetland replenishment while meeting stringent regulatory discharge and water quality objectives.
Storm Pond P services a 153.9 ha mixed residential and commercial catchment and was designed as a permanent wet pond with offline sediment chambers to achieve sediment removal targets exceeding 85% for particles ≥50 µm prior to discharge to Nose Creek. In addition to quantity and quality control, the system incorporates active reuse of stored stormwater to offset potable water demand and support downstream aquatic features. 
Stormwater reuse for irrigation is achieved through controlled pumping from the pond’s permanent storage zone between defined lower and upper normal water levels. Reclaimed water is used to irrigate approximately 15.3 ha of parks, sports fields, school sites, and landscaped open spaces, with irrigation demand and withdrawal rates governed by evapotranspiration, soil infiltration capacity, and seasonal operating rules. The reuse system is explicitly modeled within a continuous PCSWMM framework to evaluate long-term water balance performance and ensure compliance with watershed runoff volume targets.
In parallel, stormwater is reused to replenish an adjacent constructed wetland (Wetland Q), providing ecological support and additional volume management benefits. Automated control rules regulate pumping based on pond water levels and seasonal conditions, ensuring wetland replenishment without compromising flood storage capacity.
This case study illustrates how storm ponds can function as multi-purpose water infrastructure, integrating stormwater reuse, irrigation efficiency, and wetland sustainability into urban drainage systems. The approach offers a transferable framework for municipalities seeking resilient, climate-adaptive stormwater solutions that extend beyond traditional conveyance and detention objectives.

EPCOR Water Services owns and operates over 240 stormwater management facilities in the City of Edmonton and has been undertaking various initiatives to improve the safety of these facilities - in particular wet ponds. In 2017, EPCOR completed an initial safety review which included a jurisdictional review of existing SWMF safety practices, an assessment of gaps between EPCOR's SWMF safety standards and those of other jurisdictions, and identification of improvements to EPCOR SWMF standards. In 2019, Stantec conducted field inspections of all of EPCOR's wet ponds and completed risk assessments and identification of safety deficiencies to prioritize which sites required immediate attention. Since this field program, EPCOR has continued to refine their risk assessments of these facilities and has commenced design and construction efforts with Stantec on 10 wet ponds throughout Edmonton.  
A challenging aspect of wet pond safety is balancing the need for access to the pond for maintenance/inspections, visibility around the shoreline, and barriers for public access (which often inhibit maintenance access & visibility). EPCOR and Stantec have been developing a vegetative barrier approach using plant species that complement the existing vegetation, provide deterrents to for public access, and include view-corridors for maintenance and operations purposes. Surveys were used to collect resident feedback on a variety of topics including existing use of the space around the wet ponds, proposed plant species, and reiterating the importance of safety around these stormwater facilities. 
This presentation will share the story of assessment, risk identification, public consultation, and design & construction efforts which were undertaken (and continue to be pursued) to improve safety at EPCOR's wet ponds.