The National Drought Group, which comprises representatives from organisations including the Environment Agency, Met Office, water firms and regulators, made the declaration of a nationally significant water shortfall, external after meeting on Monday.
Five regions in England, mainly in the North, have drought status.
The National Drought Group’s chairwoman, Helen Wakeham, said it was calling on “everyone to play their part and help reduce the pressure on our water environment” following six months of below-average rainfall.
Bristol Water said it did not have plans for a hosepipe ban but was monitoring the situation closely.
“Small actions – like taking shorter showers or using a watering can instead of a hose – can all add up,” a spokesman said.
The company said it had been investing in major leakage reductions, which was “already having an impact”, and had given thousands of customers free water-saving devices.