Blue, green or grey water? 

Before applying the circular economy concept (figure 6) it is important to understand the source of water – is it blue, green or grey?

Figure 5 shows the competition there is for blue water, which is a finite resource. It must be shared equitably, as the more we give to one sector, the less we have for another. 

At the Water Matters Conference 2024, it was stated that in the commercial UK market, 1% of organisations use 50% of the water. Water Resources East reports that as much as 75% of the total water demand for commercial and non-household buildings could be met with recycled rainwater or grey water, thus reducing their reliance on blue water. Other countries are using grey water for landscaping – are we culturally ready in the UK to use grey water in this way?

As a user of blue water, the rural sector has a responsibility to look at ways to reduce its reliance and increase the use of green and grey water. One option would be the reuse of grey water in toilet flushing systems, which seems an obvious circular network that could be explored. Adopting either the use of grey water or rainwater harvesting for toilet flushing alone could save 40% of mains water uptake.

Additionally, final treated wastewater (for other uses, such as industrial processes and irrigation systems) can help support resilience. While this was an option available to the agriculture sector during the drought of 2022, the practicalities of moving water, requirements for regulatory permitting through the EA and the infrastructure required, meant it was not feasible for all. It is hoped Defra and water companies will explore this opportunity and remove barriers to its use in the coming years. 

Rural estates are in a fortunate position to be able to build a toolbox of solutions to reduce reliance on blue water. Savills research has assessed these (figure 7) in terms of cost, difficulty in executing and relative effectiveness. A number of these solutions can be seen in our case studies on the following pages.

Water for food production

Blue water for agriculture is mainly taken for irrigation, which helps to produce over 50% of potatoes and 25% of all vegetables and fruit grown nationally.

Tim Hess of Cranfield University suggests water demand for agriculture in an average year around 2050 will be 71–150% higher than current demand, depending on different scenarios such as climate change impact.

Scotland has seen an increase in demand for land with a sustainable water supply. Evelyn Channing of Savills Rural in Scotland says, “During the last serious drought in England and Wales, we saw an upturn in interest north of the border from livestock farmers looking for units that could produce consistently good crops of grass.

“We know that water security is a driver for many international buyers contemplating food security through agricultural investment in the UK.”

In addition to the domestic water use of 145 litres per person per day, Tim suggests we 'eat' 2,400 litres of water per person per day (water used to produce food and drinks) in a typical UK diet. This is equivalent to taking 39 showers per day. With the government saying “food security is national security”, water security should also be a priority – it must be remembered that when reviewing imports in a food security context, we are often importing water scarcity challenges.

Figure 7 highlights the effectiveness of on-farm reservoirs in building water resilience. The ability to capture water, store it and use it in the future will become essential and is emphasised by our case study from James Brown at Pollybell.

Figure 8 shows the number of planning applications for new reservoirs across the UK since 2013 and highlights the impact of grant funding. The 2018 Water Environment Grant prompted a 203% increase in applications during 2018/19 compared to the previous two years, and the Water Management Grant has seen applications rise by 224% during 2022/23 compared to the two years prior. The data indicates a 54% increase between these two grants in project applications to protect water supply on-farm.

England has the vast majority of existing reservoirs in the UK compared with Wales and Scotland, which have much less need due to their natural resources. However, we are starting to see more applications in Wales and Scotland for the first time as a result of their increasing need to build resilience.

The Water Management Grant was open in England to horticultural and arable businesses growing irrigated food crops, ornamentals, or forestry nurseries. Grants (of up to 40%) were awarded on capital items to improve farm productivity through more efficient use of water for irrigation, the use of best practice irrigation equipment, and to secure water supplies through construction of on-farm reservoirs.

The grant received 440 applications across two rounds. Figure 9 shows that for round one (2021), 20% of the applications for reservoirs were funded, along with 22% for irrigation and 11% for technology. Round two is progressing but shows a decrease in overall applications of 23%.

In addition, in 2024, the government invited applications from the agricultural sector to apply for a Local Resource Option (LRO) screening study – a study into a scheme that improves the resilience or supply of water in a local area. The EA is currently working through the applications and hopes to award funding soon.

Barriers to a circular water economy 

The question remains, do we have enough water to meet the demands of a growing population? The biggest challenge is driving behavioural change – we can still access food products imported from so-called water shortage countries, and when we turn on the tap, water appears. We all need to change our relationship with water, to implement the reduce, reuse and recycle approach in every way possible. A lesson learnt from Cape Town, following its countdown to 'day zero'⁴ in 2018, was that highlighting the severity of the situation to the wider population, while risky, did prompt consumption reduction.

^{4 When Cape Town would become the first major city in the world to run out of municipal water.} 

_{Read the articles within Water: building resilience below.}