AB-2025-05713 - Deformation Survey - Jensen Dam

Deformation Surveys
• No previous deformation surveys have been performed on Jensen Dam.

\Record/Topographical Surveys
• As part of the last Dam Safety Review, a site topographic survey was completed in September 2024 to generate the dam crest profile and cross sections of the Jensen dam.

Area of Concern – Slope Instability and Instrument Locations
• Slope instabilities in the West Coulee area and along the west canal embankment are a concern for Operations.
• Updated location and/or elevation data are required for all instruments.
• The elevations of Fuse Plugs #2A and #2B, measured during the 2024 DSR, are significantly lower than the design elevations.

Existing benchmarks and monuments
• The benchmark(s) that is referenced in past reports and drawings is survey control point(s) CP1, CP2 and ASCM which are used for the topographic survey during the recent DSR. The table below is a summary of data on file for the control points.


There are no existing deformation survey monuments. The existing instruments on site include:
• 6 standpipe piezometers
• 11 pneumatic piezometers
• 2 vibrating piezometers
• 4 slope indicators (needs to be confirmed in the site)

Scope of work The scope of work for this project will include:
• the design of the deformation monitoring network,
• installation of survey monuments,
• a baseline survey of the embankment and appurtenant structures, and
• survey data analysis.
• Review the document titled 'Standards and Specification for Deformation Surveys (1988), Alberta Environment'.
- Identify outdated sections based on current standards, published guidelines, and industry best practices.
- Provide detailed comments and recommendations for updating the document.
- The comments will serve as input for future updates to the document.