Hard water by region
Hard water in Nouvelle-Aquitaine
In Nouvelle-Aquitaine, water hardness ranges from 15 to 30 °fH. This level drives how quickly limescale builds up in pipes, water heaters and appliances. Find the LIMPEO solution that fits your situation.
Local geology
calcaires du bassin aquitain
Departments covered
12 departments
Limescale risk level
Moderately hard — monitor
Understanding hard water in Nouvelle-Aquitaine
Nouvelle-Aquitaine is the French region where hardness varies most. In the north and along the coast, the Aquitaine basin limestone yields distinctly hard water: Poitiers and La Rochelle reach a median of 31 °f, Charente and Dordogne 27 °f. In the south-west, the Landes sands and the Pyrenean foothills soften things markedly: Pau falls to 13 °f, the Landes to 12 °f. In the east, the crystalline basement of the Limousin gives the softest water in the region — 9 °f in Limoges, 4 to 5 °f in the Creuse and Corrèze. Bordeaux sits in between at 18 °f. In short, the same appliance does not have remotely the same life expectancy in Poitiers and in Limoges.
Departments of Nouvelle-Aquitaine
Hardness can vary by several °fH depending on the department and municipality. Verify exact hardness on your water bill or via the interactive map below.
- 16
- 17
- 19
- 23
- 24
- 33
- 40
- 47
- 64
- 79
- 86
- 87
Water hardness by city in Nouvelle-Aquitaine
Departmental figures from the official drinking-water monitoring programme. Your commune's actual hardness may differ from the departmental average.
| City | Department | Average hardness | Range | Classification |
|---|---|---|---|---|
| Bordeaux | 33 | 18°f | 13–22 °f | Moderately hard |
| Limoges | 87 | 9°f | 6–11 °f | Soft |
| Poitiers | 86 | 31°f | 27–34 °f | Hard |
| La Rochelle | 17 | 31°f | 25–34 °f | Hard |
| Pau | 64 | 13°f | 9–17 °f | Soft |
Departmental medians of water-hardness analyses. For your commune's exact figure, check your water bill or the French Ministry of Health portal. Source: Hub'Eau / SISE-Eaux (Ministère de la Santé, ARS) (updated 2026-06)
Our recommendation
The right LIMPEO protection for Nouvelle-Aquitaine
With moderate hardness, limescale slowly accumulates in water heaters and appliances. A LIMPEO J-250 effectively protects residential setups.
LIMPEO solution at a glance
- No salt, no chemicals, no maintenance
- Non-invasive install in under 30 min
- Compatible with all pipe materials (copper, PEX, PVC, multilayer)
- 20+ year lifespan, zero consumables
Frequently asked questions — Nouvelle-Aquitaine
Local questions
Is the water hard in Bordeaux?
Moderately. Gironde shows a median of 18 °f, within a 13–22 °f range: moderately hard water, well below the figures for Poitiers or La Rochelle. Deposits do occur, but slowly.
What is the water hardness in Poitiers and La Rochelle?
Both cities sit at a median of 31 °f — Vienne between 27 and 34 °f, Charente-Maritime between 25 and 34 °f. That is hard to very hard water, comparable to Île-de-France, and by far the most demanding in the region.
Where is the water softest in Nouvelle-Aquitaine?
In the Limousin and the Pyrenean foothills. Limoges sits at a median of 9 °f (6–11 °f), the Creuse at 4 °f and the Corrèze at 5 °f, on granite basement. Pau, in the Pyrénées-Atlantiques, is at 13 °f.
Do you need limescale treatment in Nouvelle-Aquitaine?
The regional spread is such that you have to reason at department level. Above 25 °f — Vienne, Charente-Maritime, Charente, Dordogne — yes. In the Limousin, no. Where it is useful, LIMPEO acts on the crystallisation of limescale (aragonite, less encrusting), with no salt and no maintenance.
What is the water hardness in Nouvelle-Aquitaine?
In Nouvelle-Aquitaine, water hardness ranges from 15 to 30 °fH depending on the water source. The value varies locally — your water bill shows the exact hardness for your municipality.
Why is the water harder in Nouvelle-Aquitaine?
Hardness comes directly from local geology in Nouvelle-Aquitaine. Water flowing through limestone, sedimentary or chalk rocks dissolves calcium and magnesium ions, which form limescale.
How do I know if limescale is affecting my system?
Early signs: visible scale on faucets, white marks on dishes, lower shower pressure, rising water-heater electricity bills. Above 25 °fH, scaling becomes unavoidable without protection.
Do I need a salt softener for very hard water?
No. Salt softeners add sodium to your water (not recommended above 200 mg/L per ANSES) and consume 100–300 kg of salt per year. LIMPEO treats limescale with an electromagnetic field — no salt, no resin — and preserves drinking water quality.
Does LIMPEO really work on very hard water?
Yes. Independent peer-reviewed studies (Trinity College Dublin 2000, Jozef Stefan Institute 2001, MDPI 2024) confirm electromagnetic treatment alters calcium carbonate crystallization, converting calcite (scaling) into aragonite (non-adherent).
Go further
Full guide: Nouvelle-Aquitaine
The detailed article: geology, impacts and solutions in your region.
All regions
Compare water hardness across the 13 regions of metropolitan France.
LIMPEO vs water softener
Side-by-side: salt, maintenance, health impact, annual cost.
The science behind
Peer-reviewed studies, calcite/aragonite mechanism, scientific validation.