Alberta

Calgary water hardness

Calgary gets its tap water from two treatment plants, and they are not equally hard. The Bearspaw plant, which mostly serves north Calgary, averaged 174 mg/L in 2025. The Glenmore plant, which mostly serves south Calgary, averaged 224 mg/L and reached 274 mg/L between January and March. Both are hard or very hard on any common scale.

Data last reviewed October 17, 2026.

At a glance

Bearspaw plant (mostly north Calgary)

174 mg/L as CaCO₃ Hard
  • Average
  • Range: 141 to 200 mg/L

In other units

US grains per gallon
10.2
Imperial grains per gallon
12.2
German degrees (°dH)
9.7
Millimoles per litre
1.74

Source: City of Calgary, Bearspaw Water Treatment Plant summary, 2025 (PDF). Data for: 2025, annual summary. Checked October 13, 2026.

Glenmore plant (mostly south Calgary)

224 mg/L as CaCO₃ Very hard
  • Average
  • Range: 181 to 274 mg/L
  • Seasonal peak January to March 2025: 208 to 274 mg/L (source)

In other units

US grains per gallon
13.1
Imperial grains per gallon
15.7
German degrees (°dH)
12.5
Millimoles per litre
2.24

Source: City of Calgary, Glenmore Water Treatment Plant summary, 2025 (PDF). Data for: 2025, annual summary. Checked October 13, 2026.

What this means for your appliances

Very hard

Scale builds fast. Descale your coffee maker and ice machine often, and clean the dishwasher and the washer about every two weeks.

Recommended for your water

Coffee Maker Cleaner

4.8(14)

Removes limescale, mineral buildup and coffee oils inside your coffee maker.

Descales for better-tasting coffee

$24.95

Ice Machine Cleaner

4.9(13)

Removes mineral buildup and odours inside your ice machine.

Descales and freshens countertop ice makers

$24.95

Dishwasher Cleaner

5.0(15)

Dissolves grease, detergent residue and limescale buildup, and removes odour-causing buildup.

Clears grease, limescale and odour buildup

$23.95

Washing Machine Cleaner

4.9(14)

Breaks down residue and odour-causing buildup inside your washer.

Removes odour and buildup from the drum and hoses

$24.95

Guides for hard water

What counts as hard water?

We use the U.S. Geological Survey scale, in mg/L as CaCO₃.

  • Soft 0 to 60 mg/L
  • Moderately hard 61 to 120 mg/L
  • Hard 121 to 180 mg/L
  • Very hard Over 180 mg/L

How to read the units

Utilities usually report hardness in mg/L as calcium carbonate (CaCO₃), which is the same as ppm. Dishwasher and softener manuals often use grains per gallon or German degrees instead. Here is how they convert:

  • 1 US grain per gallon = 17.1 mg/L
  • 1 imperial grain per gallon = 14.25 mg/L
  • 1 °dH = 17.85 mg/L
  • 1 mmol/L = 100.09 mg/L

Questions and answers

Is Calgary water hard?

Yes. According to the City of Calgary, the Bearspaw plant in the north averaged 174 mg/L in 2025, which is hard, and the Glenmore plant in the south averaged 224 mg/L, which is very hard.

When is Calgary's water hardest?

In winter. The Glenmore plant ran between 208 and 274 mg/L from January to March 2025. The City says hardness is lowest during spring snowmelt.

What is Calgary's water hardness in grains per gallon?

Bearspaw plant (mostly north Calgary): 10.2 grains per US gallon, or 12.2 grains per imperial gallon. Glenmore plant (mostly south Calgary): 13.1 grains per US gallon, or 15.7 grains per imperial gallon.

Where do these numbers come from?

City of Calgary, Bearspaw Water Treatment Plant summary, 2025 (PDF). Data for 2025, annual summary. City of Calgary, Glenmore Water Treatment Plant summary, 2025 (PDF). Data for 2025, annual summary. We update this page when a new report comes out.

Sources

Check another city