Well-adapted water and wastewater system

• Water efficient products and new development design: includes measures such as installing low-flow fixtures (like taps and toilets), and water-efficient landscaping with smart irrigation. Water efficiency measures are among the most cost-effective adaptation actions across systems.
• Behavioural changes: can reduce demand, and water and energy bills. Many people want to save water but lack clear guidance. Water efficiency labelling and smart metering, where the effects of different user choices are clear, are key to support this. Temporary use bans also reduce demand during drought.
• Efficiency in private water use for agriculture, industry, and power generation: implementing a package of adaptation actions could reduce anticipated economic losses in these systems by £2.9 billion (2025 prices) in the 2030s. Examples of adaptation actions include irrigating at night, switching to drought-resistant and drought-tolerant crops, and grey water reuse.

These adaptation actions are connected with adaptation in the land system, the energy system, the economy and finance system, the built environment and communities sytem, and in the digital and telecoms system.

• Leakage reduction: prioritising repair of the largest and most damaging leaks, and using sensors and leak detection alarms to alert water utilities and customers, allows leaks to be addressed more quickly and avoids more costly damage and waste of water. Smart meters can similarly highlight unexpected usage likely related to a leak. Reducing water pressure can cut leaks caused by burst pipes and can lower overall demand. However, this is more challenging and expensive in hilly areas where extra pressure is needed to pump water over these landforms. Water utilities also have to engage with customers regarding their water pressure needs and expectations.
• Flooding and erosion protection: includes raising assets like control kiosks and using fitted submersible pumps. Where rising flood and erosion risk makes a site unsuitable and protection is not feasible, relocating assets may be required. This prevents water supply interruptions due to key asset failure.
• Redundancy for single sources of failure: users reliant on a single water source are more vulnerable to shortages or asset failures.

These adaptation actions are connected with adaptation in the built environment and communities system, and in the digital and telecoms system.

• Reservoirs: increase water supply by storing winter rainfall for use in drier, hotter summers. Their size and location must reflect expected future demand and scarcity. In addition to large-scale water utility reservoirs, water can also be stored in smaller on-site reservoirs to increase resilience at a site level. This adaptation action is cost-effective at many sites for agriculture, industry, and power under a range of future climate scenarios.
• Interconnectors and water transfers: allow water to be moved from surplus areas to those facing scarcity via tanker trucks or infrastructure like pipes and aqueducts. The canal network can provide these links while offering amenity and recreation value.
• Pollution management to protect raw water quality: through measures like riverbank buffer zones and sustainable drainage systems (SuDS). These slow down surface water runoff before it reaches natural water bodies. This helps limit the movement of sediment and other pollutants, reducing the amount of pollution entering our water sources.
• Increasing water treatment capacity and efficiency: through appropriately sized assets and improved monitoring and innovation in water treatment processes. This ensures enough drinking‑quality water can be produced from available supplies.

These adaptation actions are connected with adaptation in the land system, the energy system, and in the built environment and communities system.

• Surface water separation: keeps rainwater out of combined sewers, preserving capacity for wastewater. This also increases the predictability of the volume of water that needs to be treated, as surface water volumes vary with weather conditions, but wastewater volumes do not. However, while this is cost-effective for new builds and high priority sites, retrofitting across the existing combined sewer network is more costly and disruptive.
• Reducing impermeable surface area: decreases the volume and rate of surface water runoff.

• Behavioural actions: that prevent blockages, help avoid sewer flooding, and keep systems functioning under more variable climate-driven flows. Clear public campaigns promoting simple steps (like putting bins in bathrooms) have led to sustained reductions in blockages of up to 60% by reducing flushing of wipes.
• Asset modifications: such as non-return valves and screens on Combined Sewer Overflows (CSOs) can reduce sewer flooding and associated pollution. Sensors can identify blockages, allowing them to be prioritised and fixed rapidly.
• Increasing asset capacity: increases the volume that the wastewater system can treat, helping it cope with peak flows during increasingly heavy rainfall. For example, the Thames Tideway Tunnel diverts substantial volumes of wastewater, cutting sewer flooding and reducing combined sewer overflows by up to 95% in a typical year.
• Improve treatment processes: through measures such as final effluent disinfection to protect water quality in high priority receiving water bodies, such as bathing waters. Decentralised treatment and reducing pollution at source may also be considered where cost-effective or needed to enable growth.