Civil Engineering


A1 Kentstone drainage Scheme

Collaboration by Civils, survey and Remediation Teams

Carnell have used their drainage expertise to self-deliver a complex drainage scheme for National Highways. This will improve the safety and road user experience at a holiday hotspot on the Northumbrian coast. 
As part of the Yorkshire North East drainage lot on the Scheme Delivery Framework (SDF) contract, Carnell were awarded the A1 Kentstone drainage scheme by National Highways. The requirement was to make improvements to the drainage systems in the verges, to reduce carriageway flooding. 

Since the start of the scheme earlier in 2023, Carnell’s civil engineering team have constructed 32 gullies, several of which were offset from the carriageway, to increase the drainage capacity. In addition, a 550m length of combined kerb and drainage was installed to quickly remove surface water. 

Surfacing of farm access and infilling in front of kerbs was carried out, and structural defects of the sub-surface pipework were made good through dig-down repairs where accessible and economical. 

Meanwhile, Carnell’s drainage survey & remediation team carried out trenchless repairs, including 147m of cured in-place pipework (CiPP) lining and 14 patches alongside robotic cutting. This was followed by a DDMS survey to National Highways specifications throughout the 1100m site extents. 

Carnell’s in-house Technical Services team process the survey and round-trip the data before uploading the condition shape file to National Highways’ Drainage Data Management System. 


Once on site, surveys of the verge found several uncharted services – including a water main – in close proximity to the new kerb line and gullies. This meant additional measures had to be put in place to ensure there were no service strikes, maintaining both the safety of the workforce and uninterrupted supply for customers, including a hotel. 

The majority of the work was completed at night under a lane closure and two-way traffic lights. At the start of the scheme, dozens of drivers were going through the red lights causing incursions into the works area when meeting the oncoming traffic. Working in collaboration with Premier Traffic Management, several solutions were put in place, including SafetyCam to all but eliminate the risk to road workers. 



– SafetyCam introduced to keep road workers safe.  

 – Using alternative techniques to avoid service strikes.  

 – Zero AFR and free from any RIDDOR reportable accidents.  

Customer Service

 – Working under lane closures and traffic lights at night to minimise disruption to road users. 

 – Keeping local residents informed. 


 – Multi-disciplinary scheme ‘self-delivered’ by several teams in Carnell. 

 – Working efficiently around buried services that weren’t on statutory undertakers drawings.