The grand opening of Great Yarmouth’s long-awaited £121 million new bridge has been delayed after builders found that a vole was living near the structure.
The animals are protected by law and the discovery brought a halt to the project while investigations were carried out to establish the creature was not being disturbed by the work.
It means the Herring Bridge will not be open in time for the town’s main summer tourism season, as originally planned.
Instead, it will not be in use until September.
Graham Plant, Norfolk County Council's cabinet member for highways, transport and infrastructure, announced the delay at a meeting of the Conservative-controlled council on Tuesday (July 18).
Asked by Labour county councillor Mike Smith-Clare when the bridge is due to open, Mr Plant said the operation to deal with an unexploded bomb in February had set the scheme back by at least 10 days.
But he added the recalcitrant rodent had further added to the delay. He said: "Believe it or not, we had a visit from a vole, which are more highly protected than bats.
"We had to find him a new home before we could continue, so there have been two or three weeks in which we have been held back."
A county council spokesman later clarified that although the vole's burrow had been discovered, investigations failed to reveal the whereabouts of the creature itself.
So work had gone ahead again, without the need to relocate the animal.
Tim Ellis, Norfolk County Council’s project manager for the Third River crossing said: "We have always been aware of the presence of voles around the site perimeter and have managed our work in accordance with the relevant legislation.
"A potential burrow was recently identified in a new area close to where we were working so we took measures to protect it by creating an exclusion zone and called in ecological experts, but no further action was required."
Water voles are protected under the Wildlife and Countryside Act 1981, making it an offence to intentionally kill, injure or take them.
It is also an offence to intentionally or recklessly disturb them in a place they are sheltering or to damage that shelter.
They are listed as rare and most threatened species under Section 41 of the Natural Environment and Rural Communities Act (2006).
Councils must have regard for the conservation of Section 41 species as part of construction projects.
The crossing over the River Yare will link the A47 at Harfreys roundabout to the port and the enterprise zone on the other side of the river.
Roads leading up to the Third River crossing are being closed in the evenings this week, so asphalt can be laid in one of the final pieces of work before it is opened.
The A47 in both directions - from William Adams Way to Beccles Road - will be closed every night until next Monday (July 24).
The closures will also affect Harfreys Road and Harfreys roundabout, as well as all adjoining slipways and carriageways.
Mr Plant added that, when it does open, the bridge would be "a great asset for Great Yarmouth".
The Department of Transport has awarded £98m towards the cost of the crossing, with Norfolk County Council covering the rest.
Construction on the bridge started in January last year, with a number of terraced homes in Queen Anne's Road and Southtown Road demolished so the project could go ahead.
BOMB DELAY
Mr Plant suggested the delay triggered by the discovery of the vole burrow was even longer than that caused by a Second World War bomb.
The explosive, which was dropped by German aircraft, was dredged up from the river Yare by contractors working on the bridge in February.
The bomb was close to two gas pipes and its discovery prompted a four-day operation to defuse it, which saw areas of the town cordoned off and homes evacuated.
The operation ended when the bomb exploded during attempts to make it safe. No injuries were reported and the bridge - and, apparently, its vole - escaped unscathed.
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