Somerset has been placed under a Prolonged Dry Weather status by the Environment Agency, the first official stage of drought. The alert follows months of below-average rainfall and comes amid warnings of ongoing pressure on water supplies.

Despite unsettled weather in July, England recorded its fifth warmest July on record, with only 89% of average rainfall. River flows and reservoir levels have continued to fall. August has brought drier weather and a fourth heatwave, with temperatures expected to reach the mid-30s Celsius in parts of the south.

Reservoir levels across England have dropped by 2% in the last week alone and are now at 67.7% capacity on average, compared to the usual 80.5% for early August. In Somerset, Chew Valley Lake and Blagdon Lake are among the lowest in the country, each now less than half full.

Wessex Water, which supplies Somerset, Wiltshire, Bristol, Bath and parts of Gloucestershire, has confirmed there are currently no plans for a hosepipe ban. However, Thames Water – which introduced restrictions in July – said "persistent and prolonged wet weather" would be required to ease the strain on supplies. It also highlighted the need to reduce the amount of water taken from the River Thames during low flows.

The Environment Agency said nearly half of England's rivers had below normal or exceptionally low flows in July, with the Wye and Ely Ouse reaching their lowest levels on record. Central England is now experiencing its driest February to July since 1921.

Helen Wakeham, the EA's director of water and chair of the National Drought Group, said: "The current situation is nationally significant and we are calling on everyone to play their part and help reduce the pressure on our water environment. Water companies must continue to quickly fix leaks and lead the way in saving water."

Residents are being urged to reduce non-essential use, including watering lawns, filling paddling pools, and washing cars or patios. The public is also encouraged to report environmental concerns such as dry rivers, algal blooms, pollution or illegal water abstraction by calling the Environment Agency hotline on 0800 80 70 60.

Met Office chief meteorologist Dr Will Lang said: "This week is starting off warmer than of late across England and Wales, with temperatures getting towards the mid-30s Celsius for some in the south. As we move into the second half of August there are indications of high pressure building and therefore largely settled conditions overall."

Meanwhile, the National Farmers' Union has warned that ongoing dry conditions are hitting agriculture hard. NFU vice-president Rachel Hallos said some farms were seeing significant yield drops, with livestock producers already using winter feed reserves.

Authorities are stressing the importance of everyday choices, such as turning off taps or even deleting old emails – which reduces demand on data centres – as part of a national effort to protect water resources, wildlife and communities.