BW9 Non-domestic water usage

Although Scotland is a relatively water rich country, there are not unlimited resources available for treatment and supply. The combined effect of climate change and the growing population may increase the pressure on available water resources (Scottish Water, 2012). Possible climate impacts include changes in the quality and availability of water resources and increased variability in rainfall patterns. Climate change may also increase the need for adaptive measures such as placing restrictions on discharging waste water back to the environment (Scottish Water, 2013).

Ensuring that resources are used in a sustainable way is critical to Scotland’s future prosperity (Scottish Water, 2012). Reducing water demand can help reduce the risk of loss of supply to customers and enable future demand requirements to be met. By monitoring both non-household and household (see related indicator BW8) water usage it is possible to assess changes in water demand. This indicator provides a measure of the effectiveness of the strategies employed to increase efficiency in water usage by non-household customers.  

Related indicators:

BW6 Water leakage and losses

BW7 Customers and zones vulnerable to supply deficit

BW8 Domestic water usage

NB27 Summer low flow events in Scottish rivers

Scottish Water is working with licensed water retailers to understand efficient behaviour and practices in the non-household sector. They aim to encourage the whole sector to adopt such practices so that by 2030, non-household customers will have improved water efficiency and will be considering their longer term needs for potable water. There are five licensed water retailers operating in Scotland, and the largest of these, Business Stream, provides water efficiency services to its customers including water audits, leakage detection, and water efficiency tips (Scottish Water, 2012).   

During the 2016-2017 reporting period, non-household water consumption averaged 394.49 megalitres (Ml) of water per day.

The water consumption statistics are calculated for a single year between 1st April and 31st March. Table 1 and Figure 1 show figures for non-household water consumption between 2008/09 and 2016/17. Earlier data are available, however prior to 2008 data were sourced via a different method, so for consistency, only data from 2008 onwards are compared (Scottish Water, 2009). The consumption in the column labelled ‘Unmeasured Non-household volume of water delivered’ relates to Supply Points which are unmetered and reflects assessed consumption derived from the Rateable Value, while the consumption in the column labelled ‘Measured Non-household volume of water delivered’ reflects the actual consumption recorded at metered Supply Points plus an element for meter under registration. The figures show a yearly decrease in the total non-household volume of water delivered over the six-year period.

Table 1  Non-household water consumption (Ml/d) between 2008/09 and 2016/17

^{Source: Scottish Water’s Annual Returns (Water Industry Commission for Scotland, 2018)}

Figure 1 Trend in total non-household water delivered 2008/09 to 2016/17.

^{Source: Scottish Water’s Annual Returns (Water Industry Commission for Scotland, 2018)}

Climate change may alter the availability or quality of water sources (Scottish Water, 2013), which could impact on future water supplies. It is difficult to make reliable predictions about future demand for water and wastewater in the business sector. As climate change may reduce the water supplies available elsewhere, Scotland’s plentiful water supplies may attract relocating businesses, which could increase water demand. However, it is predicted that businesses will continue to improve their water efficiency, thus reducing consumption per unit output (Scottish Water, 2013).  

At present, business demand for water is decreasing, and it is predicted that this will continue due to improved water efficiency. Scottish Water expects that in the longer term there will be little growth in demand for water and wastewater services (Scottish Water, 2013).

The figures show a yearly reduction in non-household water consumption. This reduction in demand for water is linked to businesses striving to reduce their costs and become more efficient in their use of water (Scottish Water, 2013). The financial motivation for businesses to reduce water usage in order to reduce their costs is a key difference between non-household and household water usage, as non-household customer usage is reflected directly in the charges they pay.

A number of factors including changes in supply pipe losses and changes in occupancy status (e.g. the reclassification of properties from vacant to occupied status) influence the non-household water consumption figures.