The construction of the North Hykeham Relief Road, Lincolnshire's largest infrastructure project, involves the installation of extensive drainage systems designed to safely manage rainwater. This includes more than six miles of drainage pipes, 127 new manholes, and ten settlement ponds along the route. These systems are crucial for collecting surface water, managing its flow into existing networks, and protecting the new road and surrounding environment.
Councillor David East, executive member for highways at Lincolnshire County Council, highlighted the importance of the drainage system, stating, "We're investing in a drainage system designed to manage water safely through the scheme for many years to come, helping protect the new road, the surrounding environment and the existing drainage networks." He emphasised the careful planning involved in such a large-scale project, ensuring long-term value for taxpayers and communities.
The drainage network also comprises 11 miles of filter drain and ten miles of pre-earthworks ditches to capture water during construction. Nine settlement ponds are situated between the A46 and Station Road, with another near the A15. These ponds allow silt and sediment to settle before water is released into existing ditches, with flow control devices and vortex separators regulating water quality and quantity.
Sam Edwards, head of highways infrastructure for Lincolnshire County Council, explained that the system is designed to manage water at multiple stages. "The settlement ponds give water time to slow down and allow sediment to settle, while flow controls and vortex separators provide additional control over the quality and quantity of water leaving the scheme," he said. Temporary measures, including silt fencing and flocculant matting, are also in place during construction.
Project Director at Balfour Beatty, Rob Lockwood, described the drainage infrastructure as a complex engineering challenge. "By carefully managing water and sediment as works progress, our teams are helping to protect the surrounding environment while laying the foundations for the long-term resilience of the new road," he stated. The systems were developed in collaboration with Anglian Water and other organisations to meet design, planning, and environmental requirements.
The North Hykeham Relief Road project was allocated £110 million in November 2020 from the Department for Transport's 'Large Local Majors' programme. More information is available at www.lincolnshire.gov.uk/nhrr.
