River Crossing Cover Investigation

Calgary, AB

ISL was engaged by the City of Calgary's Water Resources department to provide planning, design, construction administration and inspection services for a number of condition assessments of the City's water and sanitary infrastructure crossings located underneath the Bow River and the Elbow River

Phased Approach

To help the City prioritize the work, ISL developed a flexible methodology, divided the overall project into three phases and utilized risk assessment criteria.


To ensure maximum effectiveness during in-stream construction windows, constructability issues were considered during the preliminary design stage and details regarding constructibility and staging will be provided to the various regulatory agencies to help expedite the approval process when the time comes.

Disaster Recovery

The results of this investigation will be used to obtain funding from the Province of Alberta for mitigation work under the Disaster Recovery Program.

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Airdrie Northeast Servicing Study

Airdrie, AB

ISL was retained by the City of Airdrie to conduct a servicing study in the northeast quadrant to accommodate future development.

Land Uses

This study encompassed the City's water, wastewater and stormwater infrastructure in 12 quarter sections of land that are currently undeveloped and are slated for a combination of residential, commercial and industrial land uses. System capacities were evaluated, as well as the suitability of each quarter section of land for the anticipated land uses.

Models and Software

Hydraulic models were developed for both the water and wastewater networks using the City's existing GIS data and additional as-built specifications. The models for the water network were built using WaterCAD, and the wastewater network was modelled using MIKE URBAN. Both models utilized flow monitoring and hydrant testing results in their calibration.


Inadequate capacity in existing pipes adjacent to the study area was identified, and custom alignments and profiles were created using Civil 3D to accurately depict existing sewer conditions, including inadequacies. A custom GIS import protocol was developed in order to use the existing GIS data.

Final Report

A comprehensive report showing all findings was prepared for the City. Future development scenarios involving multiple potential infrastructure alignments were established, showing projected service demands for both residential and non-residential developments. Upgrade recommendations for the existing system as well as cost estimates for future development scenarios were also included.

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Redcliff Sanitary I-I Investigation

Redcliff, AB

ISL was engaged by the Town of Redcliff (population: 5600) to provide an inflow-infiltration (I-I) investigation to combat issues in the Town's wastewater collection system, which included residential sewer backups.


ISL reviewed previous wastewater system evaluations before constructing and calibrating a varied dry and wet weather MIKE URBAN model. After reviewing the wet weather I-I rates using the model, we performed flow correction routines on the existing flow monitoring data.

Open House

An open house was held to gather historical sewer backup information, and surveys were sent out requesting information about I-I contributors, such as roof leaders, sump pumps and weeping tiles.

Smoke Testing

Smoke testing, in which sections of the sewer system are filled with non-toxic smoke to locate entry/exit points, was implemented to identify other sources of inflow and infiltration.

Complex System

Complex hydraulics and structures, such as split chambers, siphons and lift stations, were present in the system. To model these complicated systems, all sewers, manholes, gravity trunks and forcemains were imported into the MIKE URBAN model individually.

Final Report

A targeted CCTV inspection was completed to assess pipe conditions in critical locations. A comprehensive report detailing all findings and upgrading cost comparisons was completed for the Town.

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Saunders Lake Stormwater Impact Evaluation

Leduc County, AB

Altalink is interested in constructing a new substation in close proximity to Saunders Lake near the City of Leduc. Before proceeding with construction, they selected three possible sites and engaged ISL to complete a Phase 1 Stormwater Impact Evaluation to determine what stormwater impacts might result from each of the three sites.

Document Review

To produce the high level document needed to evaluate each site, ISL reviewed all the regional and local stormwater management guidelines and plans, including the delineation of catchment areas and the site grading standards. We also conducted a detailed assessment of pre- and post-development release rates, downstream impacts and surface flow data.


Using this information, our team created a detailed surface model, and each scenario for each site was evaluated using XP-SWMM (2D Add-on) software. Peak site discharge rates were applied downstream of each potential site for multiple flowpaths.

Regulatory Approvals

Many high-level conversations were conducted with Alberta Environment in order to be proactive in terms of the stormwater management process and the level of regulatory risk outside of local municipalities.

Final Report

A Stormwater Management Report was compiled for Altalink's use. The report offered an unbiased presentation of potential stormwater impacts for each site, as well as recommendations and suggestions for discussion when selecting the final construction site. The report will act as a baseline for mitigation recommendations once the site has been chosen.

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Ivor Dent Sports Park Stormwater and Sanitary Servicing

Edmonton, AB

ISL was retained by the City of Edmonton to develop sanitary and stormwater servicing concepts for Ivor Dent Sports Park, a 56 ha multi-use regional sports facility in southeast Edmonton.

Expanding the Scope

The site did not have an onsite sanitary servicing concept and the stormwater management servicing and stormwater reuse concepts were not fully established. The project scope was subsequently expanded to include a stormwater management strategy, an ecological review of the existing wetland and detailed designs of upgrades to the east drainage feature and a new Pond 1 outlet structure.

Sanitary Servicing

The sanitary servicing concept included an onsite gravity sewer system that discharged into a regional sanitary trunk sewer.

Stormwater Servicing

The stormwater servicing concept involved the collection of all onsite stormwater runoff within four stormwater management facilities (SWMF). The collected runoff is then used to irrigate local sports fields.

A Water Balance Approach

A water balance approach was taken to develop a strategy for preserving the natural wetland, to develop and size live storage and irrigation storage zones within each SWMF and to develop a water management strategy to maximize the use of stormwater for irrigation while ensuring flood protection capacity is available when needed.

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