Measures to deliver deep cuts in household water demand require greater leadership and collaboration   Water Briefing: ‘Rob Lawson, Water Resources Director at Artesia Consulting explores the issues around Ofwat’s recent report on the long-term potential for deep reductions in household demand in the context of current AMP7 business planning.

Rob Lawson: Ofwat published their report on the long-term potential for deep reductions in household water use in early May. This identified four future scenarios that illustrated how personal water use could be reduced to between 49 and 83 litres per day by 2065, compared to the current national average of 141 litres per person per day.

But first some background.

Consumption of water in the 1960s was around 85 l/head/day. Back then we used less water for personal washing (typically a bath once a week), and usually washed clothes and dishes by hand. The gradual increase in water use over this time reflects increased living standards and an increase in volumes used for personal washing – especially showering. Seventy percent of the population have a full body wash at least daily, mostly by showering. So whilst it’s right to claim that a quick four-minute shower is more efficient than a bath, a shower every day will use more water than a bath once a week! This fundamental change in personal washing habits has driven a significant part of the increase in household demand we have seen since the 1960s.

Average water use peaked at around 155 litres per head per day (l/h/d) in the mid-1990s. Figure 1 shows that water use has fallen since around 2005 to a rate of 141 l/h/d in 2015/16.

This reduction is due to a range of factors including:

• Annual water efficiency targets by Ofwat for companies.
• The introduction of the water stressed area classification to extend metering.
• More focus on water efficiency in new homes.
• Establishment of Waterwise.
• Regulations for smaller toilet cistern sizes.

The current water resources management plans indicate a broadly similar rate of reduction in consumption over the next 25 years and the Ofwat report estimated that if the average demand reduction forecast for the next 10 years is maintained to 2065, the PCC in 2065 would be about 105 litres/head/day.’ Click here to read more.