Steep Slope Validator

Planning calculator

A tool for checking whether a slope may trigger local government steep slope review requirements.

How it works

The tool calculates slope using vertical rise and horizontal run. It can be used for a single transect, such as a driveway or building footprint, or for a multi-point area average where topography is more complex. The result is compared against the bylaw threshold entered by the user. It also flags results within 5 per cent of the threshold as a cautionary zone, recognizing that GIS contours, LiDAR-derived slope data, and desktop mapping can include vertical and horizontal tolerances.

When to use it

  • Best used for quick checks during development review, pre-application discussions, field visits, counter enquiries, or staff report preparation.
  • Not used for replacing a geotechnical assessment, geodetic survey, professional site plan, or Qualified Professional review where required.
  • Audience: Planners, development review staff, applicants, consultants, and property owners who need a clear preliminary slope check.

Notes and limits

  • Assumption: The tool assumes the rise, run, and threshold values entered by the user are accurate.
  • Known constraint: The tool does not verify source data, legal boundaries, mapped hazard areas, or bylaw interpretation.
  • Edge case: Where the result falls within the cautionary zone, the site may warrant field verification or review by a Qualified Professional before relying on the result.

Disclaimer

This tool is for general information only. It may contain errors or omissions. Use at your own discretion. No liability is accepted for decisions made based on this tool.

Related Tools