Consumers in Cornwall and Devon will be offered cheaper bills in return for cutting their water use as the region struggles to cope with a rise in the number of new residents who work from home. From next year, South West Water (SWW) – which was fined in April for dumping sewage illegally into rivers and the sea – will offer residents new tariffs designed to encourage reducing water use amid concerns about the strain caused by increased numbers of tourists and home workers. The company, owned by Pennon Group, will trial several new offers, including an “environmental tariff” that will “reflect the higher cost of peak summer demand” but offer discounts over the winter when water is less scarce. Residents in the south-west were subject to a hosepipe ban that lasted for more than a year and was lifted only in September as reservoirs were replenished. SWW data shows its customers’ household consumption has risen nearly 13%, from 312.4m litres a day in 2019-20 to 352m litres a day in 2022-23. SWW said the population had swelled by 300,000 over the past 10 years and was expected to grow by a further 530,000 by 2050. “The assumption is this has been driven by retirees or, following the pandemic, those able to work from home all or some of the time,” it said. The boom in working from home kickstarted by Covid lockdowns brought fresh impetus to a trend for Britons leaving cities in favour of working remotely in the countryside or coastal locations, notably in Devon and Cornwall. The counties were also popular holiday destinations when UK-based trips dominated the travel industry during the pandemic. However, both trends exacerbated tensions between second homeowners and day trippers, and permanent residents of the south-west. SWW estimates that the number of second homes is as high as 40% in tourist hotspots, and typically 10% in other coastal areas. It says the population increases from 3.5 million to an estimated 10 million in the region in the summer. In a recent submission to the regulator Ofwat, Pennon said: “Customers have told us they feel they are paying a premium for the high peak summer demand we experience when visitors come into the area. Most SWW customers use water meters, rather than paying on fixed tariffs. SWW’s planned “eco tariffs” would reward low consumption levels with discounted tariffs. Those on social tariffs, which offer lower rates for vulnerable customers, will not be included in the trials. The company said 10% of households in the region have a hot tub, which was another post-pandemic trend. But a spokesperson said it was not currently planning to trial specific tariffs for hot tub owners, although “customers who use more water because they have a hot tub will see higher bills as a result”. SWW has been one of a number of water companies criticised over its record in polluting England’s waterways and the accurate reporting of leaks. Susan Davy, the chief executive of Pennon Group, gave up her bonus in May in the face of public opprobrium. Pennon – which also owns Bournemouth Water and Bristol Water – has proposed raising bills from £504 a year in 2025 to £620 in 2030 for SWW customers. The group plans to invest £2.8bn on improvements, including cleaning beaches for swimming and resurrecting plans for the Cheddar Two reservoir.