A project by United Utilities to construct a network of storm water storage tunnels under Bolton Arboretum and Longsight Park has taken a big step forward with the launch of a micro-tunnelling machine.

The machine named Jane, in recognition of Jane Wilcock from the Friends of Longsight Park, was lowered into a launch pit and will now spend the next 87 days tunnelling a 900m route from Firwood industrial estate toward the arboretum before making a sharp turn back to its final destination in Longsight Park.

When complete the tunnels will store more than 3,000 cubic meters of storm water. They will play a vital role in improving water quality in Bradshaw Brook, a tributary of the River Irwell, by reducing the number of times that storm overflows operate in heavy rainfall.

The innovative micro-tunnelling machine will be navigated from an above ground control-centre via a laser-guided navigation system to dig down to a maximum depth of 38 metres.

The pre-made sections of pipeline will be automatically installed behind the machine with the excavated spoil crushed and brought to the surface using a suction system. Where possible the excavated earth will be recycled and used to backfill the excavations.

The scheme is one of four projects that United Utilities is currently working on in Bolton to improve river water quality across the borough. The company is upgrading its treatments works in Bolton to increase the capacity of the works, improve the treatment processes at the plant and reduce the time that the storm overflow operates.

There are also schemes at Astley Bridge and Dunscar Bridge.

The project at Astley Bridge will see a 400 cubic meter storage tank built in Haywood’s Hollow. As well as extra storage, a new screen will be fitted to the overflow to help improve the water quality in Astley Brook.

At Dunscar Bridge a 200 cubic meter storage meter tank with a screen will be built to help improve the water quality in Eagley Brook and Gale Brook.

Chris Borradaile, County Business Leader for wastewater in Greater Manchester at United Utilities, said:

“We’re really pleased to be getting underway with this important scheme that will help to improve the water quality in Bradshaw Brook.

“The great thing about this scheme is it also means that access to both the park and arboretum can be maintained while Jane is busy tunnelling away deep underground

“We’re not just focused on this site in Bolton, we’re actually investing nearly £150 million across four schemes in the borough and it will really help us to deliver the step change in performance that we know people want to see.”

Jane Wilcock and other members of the Friends of Longsight Park joined members of the project team to see the launch of the tunnelling machine.

Jane Wilcock commented:

“It is pleasing to see this huge infrastructure project being delivered in a way that minimises damage to the park and Bolton's arboretum.

“A few of us have been trained in river health testing and we look forward to seeing an improvement in river larvae and so insects and from there general increased biodiversity, in a brook which already has wild brown trout.”