Quick Answer: Des Moines water is Hard, averaging 12–14 gpg (205–239 ppm). That places it well above the US national average of ~10 gpg. Des Moines draws from Raccoon River + Des Moines River. Yes, worth considering. At 12–14 gpg, scale is noticeable. A 32,000-grain softener handles most households. If you have a tankless water heater, softening is especially recommended.
Des Moines Water Hardness at a Glance
Des Moines, IA — Water Hardness Data
Hardness Range12–14 gpg (205–239 ppm)
ClassificationHard
US National Average~10 gpg (171 ppm)
Primary Water SourceRaccoon River + Des Moines River
Water ProviderDes Moines Water Works
Softener Recommended?Yes — consider it
Hardness Scale Position
Soft (0–3.5)Moderate (3.5–7)Hard (7–10.5)Very Hard (10.5+)
This city's hardness sits above the national average.
Why Is Des Moines Water So Hard?
Des Moines draws from the Raccoon and Des Moines Rivers — both of which flow through Iowa's limestone and glacial till plains. Iowa sits on thick sequences of Mississippian and Devonian limestone covered by calcium-rich glacial deposits. Surface water picks up dissolved minerals from both the rock and the till, producing consistently hard water across the state.
The USGS classifies Des Moines's 12–14 gpg as Hard.
How Des Moines Compares to Other Major Cities
| City | Hardness (gpg) | Classification |
|---|---|---|
| Des Moines, IA (this city) | 12–14 gpg | Hard |
| Las Vegas, NV | 16–17 gpg | Very Hard |
| Phoenix, AZ | 16–18 gpg | Very Hard |
| Indianapolis, IN | 14–16 gpg | Very Hard |
| Chicago, IL | 8–11 gpg | Hard |
| Atlanta, GA | 7–9 gpg | Moderately Hard |
| Denver, CO | 4–6 gpg | Moderately Hard |
| Seattle, WA | 1–3 gpg | Soft |
| Vancouver, BC | 0.3–0.6 gpg | Soft |
| US National Average | ~10 gpg | Hard |
What Hard Water Does to a Des Moines Home
At 12–14 gpg, scale damage in Des Moines is noticeable. Here's what that looks like in practice:
- Water heaters: The US Department of Energy estimates scale reduces water heater efficiency by up to 30% for every 5 gpg of hardness. Tank and tankless units accumulate scale on heating elements and heat exchangers, forcing them to work harder.
- Dishwashers: White film on glasses and dishes is common. Spray arm ports clog with scale, reducing cleaning performance — see our guide to hard water and dishwashers for solutions short of a full softener.
- Showerheads and faucets: Visible white mineral deposits accumulate on fixtures. Flow rates drop as scale narrows openings. See our guide on hard water and hair for tips on protecting hair and skin.
- Pipes (older homes): Calcium carbonate deposits gradually narrow pipes over years, reducing pressure in homes over 15+ years old.
- Skin and hair: Mineral film on skin after showering and dull, brittle hair are common complaints. Those with eczema may see flare-ups — see our hard water and eczema guide.
- Coffee and tea: High mineral content affects extraction and flavor. Hard water and coffee — what the science says.
💡 Check Your Exact Hardness: Hardness can vary by neighbourhood and distribution zone. Des Moines Water Works publishes annual Consumer Confidence Reports with exact hardness data. Well water users should test annually — groundwater hardness varies significantly from municipal supply.
Best Water Treatment for Des Moines Homes
At 12–14 gpg, a whole-home water softener is worth considering to protect appliances and plumbing. The EPA's Consumer Confidence Report program requires Des Moines Water Works to publish annual contaminant data — check it for your specific address.
Fleck 5600SXT 32,000 Grain — Right-Sized for Des Moines
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See our full best water softeners guide and RO vs water softener comparison for detailed side-by-side recommendations.
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Des Moines Metro Area — Water Hardness Nearby
Omaha Ne14–16 gpg · Very Hard
Kansas City Mo10–14 gpg · Very Hard
Minneapolis Mn12–15 gpg · Very Hard
Chicago Il8–11 gpg · Hard
St Louis Mo8–12 gpg · Hard
Frequently Asked Questions — Des Moines Water Hardness
Is Des Moines water hard or soft?
Des Moines water is Hard, averaging 12–14 gpg (205–239 ppm). This is above the US national average of ~10 gpg. Des Moines draws from Raccoon River + Des Moines River.
What is the water hardness in Des Moines, IA?
Des Moines water hardness is approximately 12–14 gpg (205–239 ppm), classified as Hard. Des Moines Water Works publishes annual water quality data in its Consumer Confidence Report at www.dmmww.com.
Why is Des Moines water so hard?
Des Moines water is hard because of its source geology: Raccoon River + Des Moines River. The rock formations this water travels through dissolve calcium and magnesium carbonates, producing hard water.
Do I need a water softener in Des Moines?
Yes, it's worth considering. At 12–14 gpg, scale builds up noticeably over time. A softener isn't urgent but will extend appliance lifespans and reduce maintenance.
Does Omaha Ne have similar water hardness to Des Moines?
Omaha Ne has water hardness of approximately 14–16 gpg — classified as Very Hard. The two cities have different hardness levels due to different water sources and geology. See the Omaha Ne water hardness guide for details.
How does Des Moines water hardness compare to Kansas City Mo?
Des Moines averages 12–14 gpg (Hard), while Kansas City Mo is approximately 10–14 gpg (Very Hard). The difference is due to different water sources and underlying geology. See the Kansas City Mo water hardness guide.
Related Guides on HardWaterHQ
Iowa & Regional Water Hardness
- Iowa State Water Hardness Guide — All Cities Ranked
- Omaha Ne Water Hardness — 14–16 gpg · Very Hard
- Kansas City Mo Water Hardness — 10–14 gpg · Very Hard
- Minneapolis Mn Water Hardness — 12–15 gpg · Very Hard
- Chicago Il Water Hardness — 8–11 gpg · Hard
Des Moines Water Quality & Contaminants
- Des Moines Full Water Quality Guide — PFAS, Contaminants & Treatment
- Best PFAS Water Filters 2026
- Does Brita Remove PFAS?
- Berkey vs Clearly Filtered
Hard Water Problems & Solutions
- Hard Water and Dishwashers — Fixes Without a Softener
- Hard Water and Hair Loss — What the Research Says
- Hard Water and Eczema — Is Your Water Making It Worse?
- Hard Water and Coffee — How Minerals Affect Your Brew
- Well Water Iron Problems — Diagnosis & Treatment
Buyer's Guides
- Best Water Softeners for 2026 — Sized for Every Hardness Level
- Best Whole-House Water Filters 2026
- Best Whole-House Water Softeners 2026
- Reverse Osmosis vs Water Softener — Which Do You Need?
- How to Test Water Hardness at Home
- Salt-Free vs Traditional Water Softeners