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file 01topic · water7 figuresengagement →claims register →
last updated · 2026.04

Calgary water,
measured against its own ceilings.

Public data on Calgary’s water system, drawn directly from the City of Calgary and its open-data portal. Each figure on this page cites its publisher and any transformation we applied; the JSON behind every chart is committed to the public repository. For the specific public claims being made about these figures — and our responses to them — see the claims register.

water · case filepeak demand · observed
698
ML/day
2025-06-09 — about 73% of plant capacity. Even at peak the plants have headroom; the 2024 Bearspaw rupture showed the feeder main, not capacity, is the system's actual fragility.(/water/daily)
Bow summer flow vs 1912–1941
-28%
30-year means at WSC gauge 05BH004 — early (30 yrs) vs recent (30 yrs). Annual mean has shifted -7%; the summer (Jul–Sep) season — when demand peaks — has dropped further.(/water/bow-flow)
plant capacity · daily
950ML/day
Bearspaw 550 + Glenmore 400 post-upgrade. Binding daily ceiling — annual headroom doesn't help on the worst day.(/water/daily)
residential · 2024
47%
Of total system water — including non-revenue water. Residential is the single largest end use; ICI, regional, and municipal split the remainder of the revenue 78%.(/water/demand#sector-shares)
water loss program · 2027–2030
51%
$179.4M of the $353.9M Plan budget goes to the Accelerated Water Loss Program (pipe replacement, leak detection, cathodic protection).(/water/budget)
[02.A]

System per-capita demand, 1997–2023

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.

Per-resident demand fell 37% across 26 years — a city-wide outcome, not a slogan. System total ÷ population × 365 — raw river-withdrawal litres per Calgary resident per day. Differs from the City’s published per-capita demand figure, which excludes water resold to regional customers and uses a billed-account denominator.
[02.B]

Seasonal per-capita use, 2010–2017 mean

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.

Summer use runs ~20% above winter — almost entirely outdoor watering, which is what the stage restrictions actually target. Seasonal means of monthly single-family per-capita values across 2010–2017 · Winter = Dec/Jan/Feb · Summer = Jun/Jul/Aug · Spring/Fall = Mar–May + Sep–Nov.
[02.C]

Indoor baseline vs summer outdoor add-on

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.

Indoor use is roughly flat year-round; the seasonal swing is almost entirely outdoor watering — the lever the Plan and the stage restrictions both target. Indoor baseline = winter (Dec/Jan/Feb) mean — Calgary outdoor watering is functionally zero in winter; outdoor add-on = summer (Jun/Jul/Aug) mean − winter mean · single-family residential, 2010–2017 dataset · assumes indoor use is constant year-round (in practice it varies modestly).
[02.D]

Sector shares & non-revenue water, 2024

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.

Almost a quarter of system water — 22% in 2024 — never reaches a billed customer; the remaining 78% breaks down by end-use sector. Each end-use share is multiplied by 0.78 so all five rows sum to 1.0.