Affinity’s rising block tariff trial helps bills, debt and usage fall

Three-quarters of customers in Affinity Water’s rising block tariff trial are paying less than those on standard tariff.

That was among the promising initial findings of the trial which started in October 2023 among 1,337 properties in Stevenage. The first block of water, which covers a household’s basic needs, is free of charge, with prices then increasing in usage blocks.

Affinity said the median bill saving was 20% but that many single-occupancy households had seen water bills halved. Among typical four-person households, bills were on average 10% lower.

This had a notable impact on affordability. Affinity shared: “Customers in the trial group cleared arrears faster and more consistently than those in the control group, with arrears falling by 25%, compared to just 9% elsewhere. Within a single month, 70% of previously indebted trial customers were back on track, suggesting a meaningful link between the new tariff and financial resilience.”

Meanwhile, water use declined by an average of 12 litres per person per day; households in the trial used nearly 10,000 litres less per property annually compared to a control group. Affinity observed: “These savings, while modest per home, have the potential to scale significantly.”

Affinity is now exploring an expansion of the WaterSave Tariff to up to 120,000 customers. It calculated that if scaled across all of its one million metered households, the tariff could reduce water demand by up to 26m litres per day, equivalent to the daily usage of more than 170,000 people. Financially, the reduction in arrears across the full customer base could total £4.7m annually.