Darren Gill, who heads up Wakefield Council's IT services, said he recognised many local residents struggled with poor internet.
It came as he announced a new 20-year deal between the local authority and broadband provider CityFibre, to roll out new infrastructure across the district.
Mr Gill said most households affected by poor service would see a significant boost within four years.
But senior councillors have expressed huge misgivings over the contract, particularly over its length, and fear some of the infrastructure could become outdated quickly.
But speaking at a scrutiny meeting on Monday, Mr Gill said the deal would offer value for money.
He told councillors: "There are some areas of Wakefield where internet speeds might as well be zero.
"20 years is the length of time to lay the infrastructure, which will be done by digging up and improving the existing technology."
Mr Gill said other broadband providers had been approached by the council, but that CityFibre was the only company that could offer "social value" and improve connections for residents, as well as the council.
He said the contract would cost less than a previous deal which only covered the council's own buildings.
He explained: "At the end of the day CityFibre was the best option in terms of what we get for the money that's been spent."
But Labour councillor Olivia Rowley warned the deal could be a "bottomless pit of expenditure" and referred to previous IT deals the council had struck which she suggested had been expensive failures.
She said: "There's going to be some change over the next 20 years.
"How can we get out of the contract if that change is so significant, that this company won't be able to give us what we need then?
"How will we get out of it if it turns out to be a failure?"
Mr Gill said that clauses were available in the contract to the council if the work was not delivered.
He'd earlier insisted: "We will hold CityFibre firmly to account on our contract management.
"It will be managed very tightly."
But more councillors expressed unease about the contract's length and said they feared people's problems with internet speed would lead to criticism of them, rather than CityFibre.
Castleford Central Councillor Tony Wallis said the improvements were needed urgently.
He told the meeting: "I live in an area where Virgin are quite good with the wi-fi, but there's another area not so far away that's not so good.
"We know how Covid-19 has shown up the disparity between people can go online and people who can't, whether it's through ability or cost.
"The sooner we can get everyone on this the better."
Local Democracy Reporting Service