Civil Engineering


East Midlands Proactive Maintenance

A jetter-led find and fix drainage solution

A desktop survey of drainage asset condition and deterioration modelling identified sections of carriageway on the M1, A1 & A46 that had a poor drainage condition with high severity flooding events, producing evidence to support the need. 

The information was provided to the asset team, alongside a programme and proposed costs, supporting the VM (Value Management) 3D Passport Stage Gate process. 

Following ‘sign-off’ from the client, the works were mobilised in two weeks. Several survey and jetting crews completed the scheme in 28 shifts, removing 604 safety critical defects from a carriageway length of 40,000m on the strategic road network. 

Find & Fix (Drainage)

Carnell have designed several survey and remediation packages which deliver quick and cost-effective solutions to improve the functionality of network drainage assets performance and extend their lifespan.

The adaptable process is devised in collaboration with the client to navigate each contract’s commercial / value management challenges to have the most effective benefit to road-users.


  • Areas of missing condition data is correlated against flooding hotspots. A jetter-led survey programme is developed which supports the 3D VM stage-gate process. The emphasis on pipe-cleansing clears blockages and facilitates additional survey data to develop future schemes.


  • Previous surveys, DDMS data and flooding hotspots uploaded to DrainageViewer. 
  • Grade 4&5 defects cross referenced with flooding hot-spot data highlighted specific pipework runs to tackle. 
  • GPS survey of 2,326 point items. 
  • CCTV survey of 82,392m pipework (85%). 
  • Jetting 82,392m pipework. 
  • 604 blockages removed.