Drought crisis in Ille-et-Vilaine since August 14, 2026

The department of Ille-et-Vilaine has been placed under drought crisis status since 14 August 2026, following a rapid deterioration of hydrological conditions. This situation is explained by several heatwave episodes, high temperatures, and a lack of significant precipitation.

Hydrological context:

• 55% of watercourses monitored by the Office français de la biodiversité are already drying up.
• Dams intended for drinking water production are rapidly emptying due to evaporation and overconsumption during periods of high heat.
• Dried-up watercourses can no longer supply drinking water reserves.

Strengthened restrictions:

• Measures apply to the entire department, for aquatic environments and drinking water.
• Drought management levels have been raised to crisis in all affected areas, including:
• Coastal basins
• Couesnon
• Vilaine Nord – Meu
• Vilaine upstream of Rennes
• Vilaine left bank (Seiche – Semnon)
• Aff
• Chère

Prohibitions and measures:

• Prohibition of water abstraction from a watercourse if the flow is below one-tenth of the watercourse’s average flow.
• Prohibition of agricultural irrigation, garden and green space watering, pool filling, vehicle and road cleaning.
• Requirement to display water consumption per cycle in car wash stations.

Inspections and penalties:

• Daily inspections are carried out by State services.
• 33 sites were inspected during the first ten days of August 2026, resulting in 12 infringement reports.
• Any offender is liable to a fifth-class fine (article R.216-9 of the Environmental Code).

Call for sobriety:

• Every user is encouraged to reduce water consumption, even beyond regulatory requirements.
• Recommended simple actions:
• Prefer short showers
• Water gardens during the coolest hours of the day
• Install flow reducers on taps
• Detect and repair leaks promptly
• Use "eco" modes on washing machines and dishwashers
• Install rainwater harvesting systems

Support measures:

• A dedicated cell for farmers was established at the end of July 2026, with a meeting scheduled for 25 August.
• Information on the partial activity scheme is being provided to affected businesses.

Requests for exemption:

• Applications must be submitted via the online platform: https://demarche.numerique.gouv.fr/commencer/demande-de-derogation-temporaire-aux-restriction-d
• Exemptions remain exceptional and conditional upon structural measures to reduce water consumption.

Additional information:

• Check restrictions by municipality at: https://vigieau.gouv.fr
• Request your free Ecodo kit to save water: https://www.eaudubassinrennais-collectivite.fr/votre-eau/comment-economiser-eau/documentation-ecodo/