A new £10 million reservoir for Affinity Water has almost doubled water storage across Luton, Hemel Hempstead and St Albans, strengthening supplies for thousands of homes and businesses as the region faces growing pressure on its water resources.

The new reservoir at Chaul End provides around 20 million litres of additional water storage, increasing the total capacity available at the site from just over 21 million litres to around 42 million litres, providing greater flexibility to move water across the network when it is needed.

Unlike the large reservoirs used to collect water before it is treated, Chaul End sits within the drinking water network, storing water ready to supply customers when it is needed. The additional storage gives Affinity Water greater flexibility during periods of high demand or disruption.

The project forms part of Affinity Water’s long-term connect 2050 programme to secure future water supplies as the population grows and climate change puts increasing pressure on water resources.

“Chaul End is a major investment in the resilience of the areas water supply. By almost doubling the amount of treated water we can store at the site, we have created a much stronger buffer to help us manage periods of high demand and disruption, particularly when pressure on water resources and the wider network is at its greatest,” said

He continued: “The reservoir was planned as part of our long-term investment in network resilience as we prepare for the challenges of population growth and climate change. This year’s hot and dry summer has absolutely demonstrated its value and having Chaul End in service when water resources were under significant pressure was hugely beneficial. We’re now applying the lessons from this project as we build Hadham Hill and Hill Reservoirs; strengthening our resilience today and preparing for the challenges ahead”.

The investment will also help Affinity Water reduce the amount of water it takes from local groundwater sources. Additional storage at Chaul End means water transferred from Grafham Reservoir in Cambridgeshire can be used more effectively across the network, leaving more water in the environment for the region’s globally rare chalk streams.

Delivered in partnership with OCU Group, the reservoir was built on Green Belt land with measures to protect and improve the surrounding environment. New grassland and wildflower areas, native hedgerow and scrub have been created, alongside replacement and additional planting to increase the biodiversity value of land previously used for agriculture.

The reservoir was constructed using a standardised system of precast concrete components manufactured away from the site, reducing the amount of construction activity required on site. Lessons from Chaul End and the recently completed Preston reservoir are now being used to help deliver future strategic storage projects at Hadham Mill in East Hertfordshire and Hills Reservoir in Kent.

"Chaul End shows what can be achieved through close collaboration and a repeatable approach to delivering strategic water infrastructure," said Denis Leahy, Operations Director at OCU.

"By using a standardised precast concrete system, with key components manufactured off site, we reduced on-site activity while supporting safe, efficient and high-quality delivery. The experience gained at Chaul End will help inform future strategic storage projects, and we are proud to have worked with Affinity Water to strengthen water-supply resilience for customers and the environment."

Chaul End will also have a role in Affinity Water’s longer-term plans to bring new sources of water into the region. The proposed Grand Union Canal transfer is planned to bring water from the Midlands into Affinity Water’s supply area by 2033, with Chaul End providing additional storage to help move water through the network to areas where it is most needed.

Together, the projects form part of Affinity Water’s plans to secure future water supplies for a growing population while reducing pressure on the environment.