‘No difference’ in water usage following launch of Affinity’s rising block tariff

There has so far been no difference in water usage among customers participating in the sector’s first rising block tariff trial, Affinity Water has admitted.

Launched last year, the WaterSave Tariff trial is designed to be a fairer, more affordable way for customers to pay for their clean water supply that’s also better for the environment.

Speaking at Utility Week’s recent Customer Summit Martin Hall, the company’s head of economic regulation, gave an insight into the first three months of the trial, during which consumers in 1,500 households in Stevenage, Hertfordshire, were allocated 30,000 litres of water for free, with progressively higher rates per 1,000 litres applied to subsequent blocks (see breakdown in graph). Affinity decided to keep a fixed charge for trialists to avoid the perception of water being completely free but this was halved to £12. Consumption is being tracked by AMR meter reads and compared against those of a control group.

Hall said: “We’ve got three months of reads so it’s really early days for this. But looking at the trial group and the control group in total, we are not seeing different water use at that aggregate level across those two groups.”

He caveated these were very early results and only covered the winter months, meaning there was little outdoor water use, including hosepipes.

He said that while overall there was little difference between water usage across the trial and control group there were “tentative” signs of more customers keeping within the free 30,000l allocation.

“Among customers who are already low users, perhaps they are trying to make that 30,000l of free allocation of water last as long as it could reasonably be made to last,” Hall mused.

He added: “We’ll need to wait until summer, that’s when people will be refilling their pools and the hosepipe will come out. It will be really good to see a demand response in the customers that we’ll be charging £4 a go.”

The trial started on 1 October last year and will last until September 2025.

Hall admitted that his “biggest fear” is that the “wrong customers”, such as those who are well off financially, end up saving water through the trial.

He added: “The people who can afford swimming pools can afford to fill them. If you’ve spent £30,000 putting a swimming pool in your garden, you are going to fill it aren’t you, whatever the mains water costs. Is it then the customers who are already modest, efficient users who are then going to use even less? So somewhere in my mind I’m scared that the wrong customers will be saving.”

The rising block tariff comes after Ofwat called on the sector to introduce innovation to charging structures and updated its best practice policy to support companies to trial alternative approaches to billing.

Ofwat suggested companies could: explore seasonal charging to lower bills in the winter; lowering bills for homes with water butts or permeable driveways as sustainable drainage; or, time of usage charges to reflect when more or less supplies are available.