Lincoln flood defences, UK

England’s Environment Agency has used NEC to protect over 4,000 homes and businesses in the north-eastern city of Lincoln from 1-in-100-year flooding by the River Witham. The city’s £13.3 million flood defences scheme was delivered to the agreed budget and programme by contractor JBA Bentley under an NEC3 Engineering and Construction Contract (ECC) Option C (target contract with activity schedule).  

A two-year contract for the works was let through the Environment Agency’s NEC-based 2013−2019 water and environment management (WEM) framework in February 2019. Following various extensions to the scope, plus the onset of the Covid-19 pandemic, the scheme was successfully completed in January 2022.  

The works involved repairing 2 km of river and dyke walls at various locations in the city, including driving new steel sheet piles from both land and water. Mechanical and electrical upgrades were carried out to near-life-expired sluices at Great Gowt, Bargate and Stamp End, with eel passes added to the latter two. Rock armour, coir rolls and brush fascines were also installed to reduce erosion and enhance biodiversity.  

The economic benefit of the 50-year-design-life scheme is valued at £33 million, and it was shortlisted for the Environmental Project of the Year in the 2022 British Construction Industry Awards. 

Collaborative approach 

Project manager Andrew Usborne says the Environment Agency uses NEC in its WEM framework as it is recommended by the National Audit Office and endorsed by the Office of Government Commerce. ‘NEC’s strict time constraints for agreeing changes and its obligation on the project team to collaborate in a, “spirit of mutual trust and co-operation,” also facilitated effective management of the many changes on this project, resulting in no claims or disputes.’ 

He says time was of the essence for the scheme, so deliverables were provided at a fast pace to protect people, their homes, businesses and livelihoods. ‘As required by NEC, the project team collaborated well and transparently. They followed the contractual processes and adhered to the periods of reply to deliver the scheme within the continually updated budget and programme.’ 

Usborne says the team were encouraged to be open and honest in all communications and to raise early warnings, resulting in 117 in total, and to attend frequent risk reduction meetings. ‘This meant that risks were brought to the team as soon as they became known so they could be mitigated and managed effectively.’ 

Change control 

He says the Environment Agency added a number of extra sites to the contract via compensation events to provide further flood resilience in and around the city. ‘The NEC change-control process was effectively managed through regular meetings to agree changes to the prices and completion date in a timely manner. This allowed the extra sites to be delivered quickly, efficiently and concurrently with the main sites under the contract. It also avoided the additional preliminary, administration and procurement costs that would have been incurred in letting separate contracts for each additional site.’ 

Usborne says the initial contract price was £4.3 million. ‘The combined value of 124 implemented compensation events, which were mainly due to the extra sites and other scope changes, was £9 million, giving a revised price of £13.3 million. After disallowed costs of just £922, the contractor’s total final certified amount for the price for work done to date was £12.2 million, giving a gain share of £1.1 million that was equally divided between the parties. This is a testament to the NEC-inspired collaborative and transparent working adopted by the project team.’  

Benefits of using NEC 

• NEC requirement to act in a, ‘spirit of mutual trust and co-operation’ resulted in the project team adopting a collaborative and transparent approach throughout the works, resulting in successful completion and an equally divided gain share of over £1 million. 
• NEC’s strict time constraints for agreeing changes combined with the project team’s collaborative approach facilitated effective management of the many scope changes. 
• NEC change control process was effectively managed through regular meetings to agree changes to the price and the completion date in a timely manner. 
• NEC early warnings and frequent risk reduction meetings meant risks were brought to the team as soon as they became known so they could be mitigated and managed effectively.