Annual river withdrawals divided by Calgary’s population, in litres per resident per day. Calgary went from 616 L/resident/day in 1997 to 389 L/resident/day in 2023— a 37% reduction while population grew from ~790,000 to ~1.42 million. The dashed reference line shows the City’s separately published 2023 per-capita demand figure (356 L/resident/day), which is lower because it excludes water resold to regional customers and uses a different population denominator.

Civic census stops in 2019; 2020–2022 are absent because no comparable City estimate was published. The 2023 point uses the April 1, 2023 estimate from the Spring 2024 Population Outlook.

Average daily single-family per-capita water use by season, 2010–2017. Summer is roughly 20% above winter for this dataset — the seasonal swing is what drives peak-day stress on the system, and it’s mostly outdoor watering rather than indoor fixtures.

A decomposition of the seasonal data: the winter bar represents essentially pure indoor use (outdoor watering doesn’t happen at −20°C), and the summer bar splits that same indoor baseline from the outdoor add-on. The outdoor portion is the variable component — what stage-based restrictions actually target. Indoor use is roughly constant year-round.

Calgary system water broken down into end-use sectors and non-revenue water (NRW) — the standard utility category that covers physical pipe leaks, meter undercounting, and authorised-but-unbilled use like firefighting and mains flushing. The City’s public copy sometimes shortens NRW to “leaks”; the Plan’s engineering target is an Infrastructure Leakage Index of 3.0 by 2030 — a utility benchmark where lower is tighter, isolating the real-loss (true leak) component specifically.