At JSM Group, we pride ourselves on delivering complex infrastructure projects while prioritising environmental stewardship.
Our recent 132kV cable crossing project – connecting to a National Grid substation – tested this commitment with unique challenges that required innovative solutions.
The challenge: Balancing infrastructure needs with environmental protection
The project required an open cut crossing of the main River Colne, which is an ecologically sensitive area and a location where two rivers meet. After extensive planning, we ruled out:
- Bridge-mounted solutions– due to structural limitations identified by local authorities
- Horizontal directional drilling (HDD)– engineering difficulties made this approach unfavourable
This left an open-cut river crossing as the preferred option – a method with higher environmental risks that demanded meticulous planning.
Ecological and environmental controls included
Ecological surveys including Phase 1 habitat surveys, water vole surveys and ground level assessments for bat roosts in trees were undertaken.
A check for otters was made prior to the start of works, with one trail camera in place for two weeks. Immediately prior to works, a further check of the banks and the island was made to ensure otters were not present in the area.
Site lighting was avoided overnight, as light can be detrimental to foraging and commuting bats which are highly likely to use the river.
Vegetation clearance (there was minimal required) was undertaken under ecological supervision.
Prior to dewatering, approximately 70 fish, including Bullheads and Perch, were moved safely over the dam.
Good practices regarding preventing pollution were always maintained, including:
- Fueling vehicles and equipment away from the river
- Ensuring machinery and equipment were well-maintained to minimise the chance of leaks
- Having biosecurity measures in place throughout the works
The bigger picture
This 21-day operation – the culmination of 2 years of design, permitting, and stakeholder coordination – underscores how infrastructure development and environmental protection can coexist.
By documenting these lessons, we’re not just improving our processes but contributing to industry-wide best practices.
Joe Scanlon, Head of Civil Operations at JSM says;
Considering the increasing engineering challenges associated with cable routes in the UK, this achievement highlights JSM Group’s capability to overcome such difficulties and ensure projects are delivered safely and efficiently.
A big thank you goes out to all teams involved.
