The authority said today that if fewer than the 17,500 trees listed in the contract with private firm Amey are removed "a financial adjustment will be made" at the end of the term. The council added it cannot yet say how the "financial adjustment" would work as Amey are not paid to replace individual trees.
It insists the 17,500 figure is not a target and it currently estimates around 10,000 of the city's 36,000 street trees will be felled and replaced with saplings over the course of the contract, which started in 2012.
But campaigners say this explanation "bears no resemblance" to the wording of the contract, which states Amey shall replace trees "at a rate of not less than 200 per year so that 17,500 are replaced by the end of the term in accordance with the Highway Tree Replacement Policy". The contract adds that this figure can only be changed if Sheffield Council “approval has been obtained for deviation from this policy”.
The council was forced to publish the previously-redacted details of the 25-year highways maintenance contract earlier this month on the orders of the Information Commissioner. While the element of the contract containing the Highway Tree Replacement Policy currently remains secret, the council has said its strategy involves only the removal of trees which are dead, dying, diseased, dangerous, damaging to the pavement or roads or 'discriminatory' - affecting the ability of people to use footpaths.
Campaigners, who say many healthy trees are being removed unnecessarily, had challenged the council to prove the contract had been changed after Bryan Lodge, cabinet member for environment, wrote to local MPs last week to say while the 17,500 was “very alarming”, the authority did not consider it to be “a target or fixed number Amey must replace”.
Mr Lodge suggested the 17,500 figure has been included to provide cover for the council should there be an unexpected outbreak of tree disease that meant larger numbers than currently planned have to be felled.
The council has now confirmed to The Yorkshire Post that no formal agreement has been made to change the contract and a spokeswoman said there is no intention to do on the grounds that the current wording “provides financial cover should it prove necessary to replace that many”.
The spokeswoman said: “We are constantly being pressed to put numbers on trees to be replaced. This is very difficult due to the ever-changing condition of the city’s street tree stock and the fact that we are unable to predict the impact of any potential disease outbreaks that may occur in the next 20 years.
“It is impossible to commit to definite numbers prior to annual assessments of our trees taking place. Importantly, the council has the final say on any street tree replacement as part of the contract and trees will only be replaced as a last resort when all engineering solutions have been fully explored.
“Whilst an estimate of around 10,000 trees to replace over the life of the Streets Ahead contract period has been given, it is just that; an estimate.
“The figure in the contract is not a target as trees will only be replaced as a last resort. It is simply a figure that provides financial cover should it prove necessary to replace that many. If, at the end of the contract, a smaller number has been replaced, a financial adjustment will be made.”
A spokeswoman for Amey said the existing contract “allows for a range of potential situation which may or may not materialise over the remaining 20 years of the contract”.
She said: “We only remove trees where absolutely necessary and the way we approach, assess and identify trees for replacement is available for all to see on the Council’s website. There’s no change to this. No-one would be able to predict with any certainty how many trees may be affected in coming years.
“As the council has made clear, this figure allows for a range of potential situations which may or may not materialise over the remaining 20 years of the contract and the Council retains ultimate control by having the final say on any tree.”