Est. 2005 · UK-wide trenchless installations07920 553 578·enquiries@swdirectionaldrilling.co.uk
Crossing Solutions
A crossing under a canal is works on the Canal & River Trust's own property, and the whole job is built around not losing water from the channel. We design the crossing to the Trust's Code of Practice, support the consent through the local Works Engineer, and drill it with the navigation and towpath open above.
Drilling a service beneath a canal keeps the work out of the channel entirely. We launch from a pit set back on one side, steer the bore well below the hard bed, and receive it on the far side, so the water, the boats and the towpath above are untouched. It is the Canal & River Trust, more than the drilling, that shapes how the job runs, so the crossing is designed around their Code of Practice from the start.
The Trust is a landowner, not a river regulator. It owns the canal, the water, the bed, the banks and a margin of land each side, so a crossing needs its consent as works affecting its property, applied for through the Works Engineer at the local Trust office, who will want an early site visit before anything is designed. The Trust’s code presumes a trenchless crossing. Open-cut through the canal is very unlikely to be permitted, an overhead crossing is not permissible at all, and the crossing is normally perpendicular to the waterway.
The code’s stated principal criterion is leakage from the canal, and its requirements follow from it:
How all of that actually runs, stage by stage from first contact to the record drawings, is walked through in our canal crossing guide. A river is a different regime altogether, the Environment Agency and the FRA3 exemption, covered on our river crossings page and walked through in our FRA3 guide.
What we handle
| Owner & consent | The Canal & River Trust owns the canal, the water, bed, banks and a margin of land each side. Consent is under their Code of Practice, through the local Works Engineer |
|---|---|
| Depth below the bed | Of the order of 3.5m below the hard bed to the crown of the pipe, varied by the Works Engineer for the ground and the method |
| Site investigation | A minimum of two boreholes, one each side of the canal, laboratory tested, taken at least 3m below the crossing invert, plus a bed survey across the full width |
| Launch & reception pits | At least 5m from the water’s edge, clear of any embankment, and raised at least 300mm above maximum canal water level, with a bund where the ground cannot give that |
| Working | Round-the-clock once the bore starts. The navigation and towpath normally stay open throughout |
| Lead time | Allow around 3 months from notifying the Trust, or around 12 months where the navigation would need to close. Current lead times and fees are the Trust’s to set |
| What we handle | The bed survey and boreholes, the crossing design and impact assessment, the method statement and the drilling. The consent and cost undertaking sit with the promoter of the works, usually the asset owner or main contractor, with our design behind them |
| Track record | A 100m, 180mm gas main steered beneath the Grand Union Canal, with the navigation and towpath in use throughout |
The depth and the investigation are confirmed with the Works Engineer against the borehole logs and bed survey, never assumed.
A canal we have crossed
We steered a 100m, 180mm gas main beneath the Grand Union Canal, keeping the navigation and the towpath in use while the main was carried across underneath, and we have installed duct routes under canals for grid-connection schemes the same way. Once a canal crossing is finished there is nothing to see from the water, the bore passes well below the bed, the pits sit back from the banks, and the only lasting sign is the pair of markers recording the line of the crossing.
You can see our river and canal work in the round on our rivers, canals and watercourses page. If you have a canal to cross, send us the details and we will show you how it would be drilled, what the Trust will ask for, and what it is likely to cost.
Questions answered
Yes, and it comes from the Canal & River Trust, not the Environment Agency. The Trust owns the canal network in England and Wales, the water, the bed, the banks and a margin of land each side, so a crossing beneath a canal is works affecting their property and needs their consent under their Code of Practice for Works Affecting the Canal & River Trust. The application runs through the Works Engineer at the local Trust office, who will want an early site visit before anything is designed, and who stays with the job through to the record drawings at the end.
The Trust's published expectation for a trenchless crossing is a minimum depth to the crown of the pipe of the order of 3.5m below hard bed level, the firm bed beneath the silt, and the Works Engineer varies it for the ground and the method. That is much deeper than the river rules ask, the Environment Agency's exemption floor for a river is 1.5m, and it is confirmed against the borehole logs and the bed survey rather than assumed. The Trust's code also requires a site investigation, a minimum of two boreholes, one on each side of the canal, with laboratory testing, taken at least 3m below the anticipated invert of the crossing.
Normally, no. The crossing is drilled from a pit set well back on one side to a pit set well back on the other, nothing enters the channel, and boats and towpath users carry on above the bore. Works that would need the navigation closed carry a lead time of around 12 months rather than 3, which is one more reason the crossing is designed to keep out of the channel entirely. Where a towpath closure is genuinely needed it is arranged with the Trust on around 4 weeks' notice.
Losing water. A canal is a man-made channel that often sits above the surrounding land on an embankment, and the Trust's code names leakage from the canal as its principal criterion. The concern runs both ways along the bore, drilling fluid escaping up into the canal, and canal water draining down through the bore into the pits. So the pits sit at least 5m back from the water's edge, clear of any embankment, raised at least 300mm above the maximum canal water level so anything that finds the bore is contained, with a bund built around the pit where the ground levels cannot give that, and the works run with a fluid break-out contingency in place, constant monitoring of the bore, and grouting held below the pressure of the ground above.
Allow around 3 months from notifying the Trust to starting on site, with the boreholes, the bed survey and the crossing design running inside that window, so the Trust's process and ours run in parallel. The works themselves are short, typically days, drilled round the clock, because the Trust requires continuous 24-hour working once the bore starts so nothing develops under the canal unwatched. The current lead times and fees are confirmed with the local Works Engineer at the start, because they are the Trust's to set.
No. A river crossing runs through the Environment Agency and normally qualifies for the FRA3 exemption, a free online registration with a 1.5m minimum depth condition. A canal crossing is consent from a landowner with a published technical code, a depth expectation of the order of 3.5m to the pipe crown, boreholes as a requirement rather than a judgement call, round-the-clock working, and a lead time measured in months. If your route crosses both, both processes run, each with its own authority.
Related services
The long version, the Works Engineer, the boreholes, the 3.5m depth, leakage control and what we need from you at each stage.
View service →Our river, canal and estuary crossings, and the real jobs behind them.
View service →The bore profile, long section and settlement calculations behind a canal crossing.
View service →Send us the waterway, the service and the line you want, and we'll come back on the crossing, the Canal & River Trust consent and a budget price.