With the row over the felling of 6,000 trees in Sheffield as part of a £2.2bn highways maintenance deal not going away, engineers are starting to wade into the debate.
A total of 6,000 trees will be felled in Sheffield by the end of this year as part of a £2.2bn Streets Ahead PFI deal between the council and Amey.
Campaigners complain healthy trees are being chopped down, while the council maintains it is doing essential work to ensure safety and protect the future of the city’s street trees. It is now being argued that several engineering alternatives to felling are not funded in the deal and that this should be reconsidered.
The 25-year highway maintenance scheme, which began in 2012, has been dogged by protests and legal action. The Streets Ahead contract and subsequent tree replacement programme has been challenged in the High Court and the Court of Appeal, with the High Court ruling the contract to be “lawful and legal” and the Court of Appeal finding the case against the council to have no merit.
The project involves “transforming” the city’s roads in the first five years and maintaining the standard for 20 years. There are 36,000 highway trees to be maintained and each tree that is felled will be replaced with a tree eight to 10 years old, the council said.
But the move has stirred up protests. In June this year 329 out of 427 attempted tree fells were abandoned and in August the Labour-run council was granted a High Court injunction banning anyone from entering a tree “safety zone”.
Now engineers are suggesting more should be done to consider alternatives to felling.
Former Trafford Council highways engineer Peter Townsend told New Civil Engineer that a comprimise would be a win-win solution. “Amey could gain publicity by showing how well they’re working environmentally with the council on a PFI contact,” he said. “It is a lose, lose for everyone at the moment and what it needs to be is a win, win” he added.
Currently, trees are classified as either dangerous, dead, diseased, dying, damaging footpaths or properties or “discriminatory” - for example obstructing wheelchair users - before a decision to fell them is made. A list of 25 engineering solutions are considered alongside felling, but only 14 of these can be carried out within the contract.
Shefffield City Council told New Civil Engineer that budgetary pressures had forced their hand. It said that “huge budget cuts” meant that “careful consideration” had to be given before exploring the other 11 options, and documents presented by the council to the High Court said there was “no money for unfunded solutions outside of the PFI contract framework”.
The solutions not funded within the PFI include the altering of line markings or carriageway kerb lines, footpath deviations, use of geogrids, use of fill instead of a sealed surface, reduction in road widths and conversion of footways into verges, road closures, changes to contract specifications, the creation of new footways or the closure of old ones.
Engineering solutions allowed within the PFI are: the use of thinner profile kerbs, excavation for root examination, ramping or reprofiling, flexible paving or surfacing, removal of displaced kerbs and filling in of pavement cracks, root pruning, root shaving, root barriers and guidance panels, tree growth retardant, the creation of larger tree pits, heavy tree crown reduction or pollarding to stunt tree growth and retention of dead, dying, dangerous and diseased trees for their habitat value.
The council said it was keen to detract attention from the ongoing tree saga that has hit the headlines and saw one protester handed a suspended sentence for breaching the injunction.
“We want our city to benefit from better roads, pavements and street lighting as well as an increased and sustainable street tree stock that can be enjoyed by generations to come,” Sheffield City Council cabinet member for environment and street scene Bryan Lodge said in a statement last month, adding that any further breaches of the injunction would leave the council with “no other option” but to pursue further court action.
Amey stressed the benefits being delivered to Sheffield residents via the Streets Ahead Scheme. In a joint response via the council it stressed that Streets Ahead was not just about street trees – “it’s about ensuring we have roads, pavements and a street scene to be proud of for many years to come”.
“It presents us with a unique opportunity to sustainably manage, increase and maintain the city’s diverse street tree stock over a 25 year period,” it said. ”The programme affects less than one percent of the city’s trees, and each tree removed will be replaced on a one for one basis. Around 400 street trees are set to be replaced before the end of 2017 with 600 additional trees being planted over the contract period.”
But Townsend insisted more consideration should be shown. “[At Trafford] we would take out three or four [trees] out of 20 and do that over a six or eight-year period. Those trees were decent size specimens, so they were reasonable sized trees by the time you’re taking down the last trees in the road, so that way you’re maintaining the leafy suburb look.
“To me there doesn’t seem to be any coordination between a tree replacement scheme of that sort of nature and the highways programme maintenance.”