Useful next steps
If you can safely reach and identify your internal stop valve, close it gently to limit a leak. Do not force a stuck valve or enter water near electrical equipment.
Take a photograph from a safe position. Note whether the leak appears to come from a visible pipe, a fixture or an unknown source behind a surface.
For water escaping in a road or pavement, use your water supplier's reporting service. Check the supplier by postcode rather than guessing from the town name.
To identify the appropriate water or wastewater provider, use Water UK's postcode lookup. A town name alone is not a reliable way to choose a provider.