Council's property manager Leighton Toy said in November 2015 the council had voted to take the cycleway along the eastern side of the river because the western route was considered too expensive - $4.3m, compared to $2m. This was for the cycleway to be taken all the way to the Aramoho rail bridge.
But Mr Toy said the cost had come down when the decision was made to take the cycleway to the start of the 50km/h - a much shorter distance.
Emmetts Civil Construction had been given preferred contractor status for its design along the western side of the river via a cable stay bridge.
"This is a more direct route along the river, so it's shorter and cheaper," Mr Toy said.
"There is no need for the council to purchase land, and this bank of the river is less susceptible to erosion. It also allows for an off-road track, which is an important point. It will be extremely safe."
Mayor Hamish McDouall asked whether the bridge would be under threat during flooding.
Mr Toy replied that the bridge was 2m higher than the level of the river during the 2015 floods.
Councillor Rob Vinsen suggested that councillors had received poor engineering advice when they made their initial decision to route the cycleway down the eastern riverbank.
"I think the advice around cost was poor, and I hope councillors become more searching of advice given," Mr Vinsen said.
However, committee chair councillor Helen Craig cautioned Mr Vinsen again "attacking the integrity of the staff and their work".
The committee passed unanimously the decision to change the cycleway route to the western side of the river, subject to NZTA approval.