Outstrays to Skeffling managed realignment, East Yorkshire, UK

NEC has been used to create 250ha of intertidal and wetland habitat on the north bank of the Humber Estuary in the East Riding of Yorkshire. The Environment Agency let the £17 million Outstrays to Skeffling Managed Realignment scheme contract to JBA Bentley under an NEC3 Engineering and Construction Contract (ECC) Option C (target contract with activity schedule) in June 2019. NEC project manager and commercial manager Arcadis and NEC supervisor WSP were each engaged under an NEC3 Professional Services Contract (PSC).

The Environment Agency scheme, which is in partnership with Associated British Ports, involved building a 5.5km embankment inland and then breaching the existing estuary embankment to create 175 ha of intertidal mudflats and salt marshes. A 75ha area of freshwater grassland has also been created alongside Winestead Drain behind the new embankment. Together the new areas help to compensate for habitat losses for birds and other wildlife along Humber Estuary caused by rising sea levels, flood defence work and coastal development. 

The project also included excavating 4.1km of new drainage channel, planting over 11,000 new trees and shrubs, and creating a new footpath, bridleway, bird hides and car park. Over 2.1 million t of site-won material was used to construct the new embankment and a sacrificial wave bund, the latter saving the need to import 40,000 t of rock armour. The wider and sister project, incorporated as further contractual sections to the managed realignment scheme, also included building new pumping stations at Skeffling and Winestead.

Construction working windows were limited to April to October each year to avoid disrupting over-wintering birds. By the end of October 2024, all work was completed on time and budget with the exception of finishing the pumping stations, which will be completed in 2025–27. 

The scheme was shortlisted for the Environmental Project of the Year in the 2024 British Construction Industry Awards and has been highly praised by local residents, politicians and those who are enjoying the new bridleway and bird hide amenities. 

Contract flexibility

The project was procured through the Environment Agency’s NEC-based 2013−2019 Water and Environment Management (WEM) framework. The scheme was tendered on an outline design which required development to full construction standard, with significant durations anticipated for both design and construction.
 
The scheme required an integrated team approach to develop efficient design solutions, mitigate risks and capture opportunities. NEC3 ECC Option C gave the flexibility to accommodate an altering scope while encouraging collaboration and innovation due to the incentivised share mechanism. The design submission and acceptance process worked particularly well, with optioneering and value engineering both in the early stages and throughout the project.    

There were several potential and unquantifiable risks due to the exposed coastal location, which required careful consideration of the risk profile of each party. The ability of the contract to accommodate a dynamic team approach, encouraging the team to work collaboratively towards mitigating these unknown factors, was key to the contract choice.

Mitigating risks

Arcadis NEC project manager Paul Crake says the NEC early warning mechanism was the key process to managing risks that became apparent during the scheme. ‘Weekly risk-reduction meetings were held throughout to bring the team together to discuss and agree suitable ways forward. The team’s mindset was always focused on how to solve the problems for the best outcome from a scheme perspective.’

 He says the NEC requirement on the parties to act in a ‘spirit of mutual trust and co-operation’ really came into play during the early warning and risk reduction meetings. ‘By encouraging this mindset, the answer was always provided from around the table. In practice, the early warning process was the key driving force throughout the project, it brought the team together on a regular basis and encouraged everyone to raise something that may have been an issue.’

Crake says the early warning process enabled everyone to feel part of a larger shared goal and work together. ‘The benefit this had on team building and general morale cannot be underestimated. On any project, it is vital to encourage a team to overcome hurdles together, and I believe that the NEC early warning process was the key to this.’

He says NEC’s clear requirement on the level of information and detail required for a programme submission was also vital to keeping the project on schedule. ‘This process enabled me as the project manager to lead the contractor to consider and develop a programme that was both informative and fit for purpose.’ 

Crake adds that the requirement for a single comprehensive programme resulted in one truth regarding expectations, addressing the risk of mixed messages and confusion. ‘Having a complete and useable document facilitated a good understanding of delivery milestones. This resulted in more informed discussions with third parties, clearer agreement of time-related variations and simpler external reporting of progress.’ 

Managing change

Arcadis cost consultant Robin Poulter says the timescales for NEC compensation events ensured that all effects of variations were proactively addressed and agreed. ‘The contract prescribed fairly short but achievable timescales for agreeing compensation events, though with a benefit of flexibility to extend time periods if needed.’

He says the contemporaneous approach to resolving commercial matters meant there were effectively few commercial matters to be resolved at the end of the contract. ‘There has been no fall out, no final account gaps and no protracted discussions after the fact. It kept all parties aware of their respective commercial positions, so there were no surprises, particularly at the end.’

Mutual trust

Environment Agency project manager Marie-Claire Spicer says the mutual trust between the contractor and the client had been developed over many years of framework partnering. ‘With this trust, any key decisions and implementation on site have been commenced to prevent programme delays while commercial agreements have at times followed later. This was only possible with a solid foundation of mutual trust and cooperation.’

She says ECC Option C enabled both parties to benefit from efficiencies delivered throughout the scheme via the pain/gain share mechanism. ‘This mutual benefit has driven innovation and efficiency throughout design and construction that may well not have been realised without incentivisation. The result of this is a happy client and contractor, and an additional benefit of some positive lessons learned that can be carried through into future projects.’

Benefits of using NEC

• ECC Option C provided the flexibility to accommodate an altering scope while encouraging collaboration and innovation due to the incentivised share mechanism.
• NEC early warning process was the key driving force throughout the project, enabling everyone to feel part of a larger shared goal and work together.
• NEC requirement to act in a ‘spirit of mutual trust and co-operation’ ensured the success of risk-reduction meetings and enabled solutions to be implemented before commercial agreements.
• NEC programme submission process ensured the programme was always a complete and useable document that facilitated a good understanding of delivery milestones.
• NEC compensation event process ensured that all effects of variations were proactively addressed and agreed, leaving few commercial matters to resolve at the end of the contract.