A major investment to prevent flooding and pollution has boosted resilience for Grimston, Congham, Roydon and Gayton, as part of Anglian Water’s region wide commitment to protecting the environment and supporting communities.

Anglian Water has now completed a £1.36 million programme of flood prevention upgrades this year across the Grimston catchment, building on the £1.1 million worth of improvements delivered the previous year. This investment is reducing the risk of sewer flooding for residents and strengthening resilience in a Norfolk catchment where flooding and environmental pollution has often posed a challenge. Delivered in partnership with the Norfolk Strategic Flooding Alliance (NSFA), the work marks another significant step forward in tackling long-standing issues in the area.

Flooding in Grimston has many causes, including sewer misconnection, agricultural and road runoff, high groundwater and general maintenance issues, meaning no single organisation can solve the problem alone. Close collaboration between agencies has been essential, and the NSFA has played a key role in bringing together highway’s teams, drainage boards and local government to deliver lasting improvements.

Henry Cator, Chairman of the NSFA, said: “Anglian Water’s sustained investment in Grimston and the surrounding villages is making a real difference for communities that have faced repeated flooding and disruption. Several partners within the NSFA worked closely with Anglian Water to complete the project. It is a clear example of how effective collaboration strengthens resilience and protects both people and the environment. Flooding is a complex challenge, and only strong multi‑agency partnership can deliver truly lasting solutions.”

These upgrades come following several years where the villages of Grimston, Pott Row, Gayton and Roydon faced repeated flooding, high groundwater levels and loss of toilet facilities, caused by infiltration, misconnections, agricultural runoff and increasingly extreme weather. These issues were made significantly worse by the very intense weather patterns and extremely wet winter and heavy rainfall of 2023/24, which put additional pressure on local systems and contributed to the scale of flooding they experienced.

Misconnections – where roofs, gutters and surface water connections are mistakenly connected to the foul sewer – can send large volumes of extra water into the system during storms and quickly overwhelm it. Groundwater infiltration and agricultural runoff add even more water during wet weather, placing further strain on the network. These issues reduce the sewer’s capacity and make flooding more likely during periods of intense rainfall.

This year’s investment has delivered a range of improvements across the area. These include steps to keep excess rainwater and groundwater out of the sewer system, strengthening parts of the pipework, and adding new controls to help manage flows during heavy rain. These upgrades make the system work better, lower the risk of flooding for local communities and help create a more reliable network.

These works build on extensive investigation work carried out over previous years by Anglian Water’s dedicated Complex Investigation and Resolution team, including CCTV surveys, door-to-door checks of roof downpipes and surveys of the highway’s drainage network. This work identified 42 roof misconnections, each capable of contributing as much water as 100 households, and new innovative methods such as TuboGel were trialled to reduce infiltration more quickly and with less disruption.

Chris Wray, from Anglian Water’s Complex Investigation and Resolution Team, said: “Customers in Grimston and the surrounding villages have endured some extremely difficult winters, with high groundwater and heavy rainfall overwhelming local systems. This investment means real improvements on the ground - fewer flooding incidents, better resilience during storms, and a network that is fit for the future. This work was only possible because of strong partnerships. Flooding challenges are complex, and we’re committed to playing our part while working closely with the Norfolk Strategic Flooding Alliance and other agencies to protect the environment and support our communities.”

Thanks to these upgrades, residents will now see greater protection for homes, roads and public spaces, with reduced sewer flooding and pollution risk that safeguards sensitive environments such as the nearby River Gaywood, a precious chalk stream. They will benefit from a more stable and resilient sewer system during extreme weather, alongside earlier detection and prevention of problems. Customers can also play an important part in keeping sewers flowing by only flushing the 3Ps (pee, poo and paper) and putting wipes, sanitary products, fats, oils and leftover food in the bin. These everyday habits prevent blockages, reduce the risk of sewer flooding and help protect homes and the local environment.

The Grimston upgrades sit within Anglian Water’s region-wide investment in environmental protection. The water company is investing nearly half a billion pounds to reduce storm spills, protect rivers and improve sewer networks. Across the region, Anglian Water will invest more than £1.6 billion into its water and sewerage networks in the East of England from April this year, the second year of its largest ever five-year plan, worth £11 billion.

Anglian Water will continue monitoring the performance of the upgraded network in Grimston and surrounding villages and will keep working with the NSFA on shared challenges, ensuring the community remains at the heart of long‑term planning for flood resilience.