A NEW flood resistance and resilience scheme for Melksham Substation costing £1.3million has recently been installed.
Owned by the National Grid, Melksham Substation, which is on the Farmers roundabout alongside the river Avon has been identified as being at risk of flooding from a 1 in 200 and 1 in 1000 year event following the 2007 floods after an independent enquiry was undertaken by Michael Pitt (The Pitt Review).
The review recognised the significant impact the widespread loss of electricity can cause, it was noted that the loss of power caused fear and distress to the public and could have serious health consequences.
The flood defence scheme was designed and built by Barhale, one of the country’s leading civil engineering and infrastructure specialists.
Barhale were employed as principal contractors, working alongside RCL, to design and build a scheme that would protect critical infrastructure assets and ensure continuity of substation services during extreme flood events.
“We’ve constructed an 81m concrete flood wall along the northern side of the main access road to divert water away from the substation,” says Abdi Rahman, site agent for Barhale’s southern office. “Spread over the whole 2.5km site, we also built a 2.4m earth bund associated with the earth bund is a ditch diversion because the earth bund cuts across the existing ditch and therefore the ditch is diverted around the earth bund and diagonally across the field in a south easterly direction. The ditch is culverted to pass under three 25kV cables from the substation, feeding Network rail assets. We also constructed new fence sills at either corners of the substation to form a higher wall and installed new 3.1 palisade electrified fencing.”
Alongside this, Barhale cleared and dredged the nearby South Brook Ditch for the entire outside parameter of the substation, to stop water draining and backing up which would lead to the site flooding.
“We’ve had a really strong team ethos on this project picking up key learnings on the way. Constructing the earth bund in cold winter temperatures was a challenge, ecological constraints also prevented us from carrying out a full dredging scope of the South Brook Ditch. From the ecological surveys carried out for wildlife habitats, we discovered great crested newt DNA and badger activities. This resulted in Barhale installing 1400m of gold crested newt fencing, exclusion zones for badger areas and habitat restoration works.”
