Tauranga City councillors this week agreed to pay an additional unbudgeted $1.8 million for a bridge across the Kopurererua Stream at Keenan Road.

The bridge was originally estimated to cost $3.3 million, but the tenders received for it are all well over that amount.

The Kopurererua Bridge will be built in the current financial year. Photo: Google Maps.

Councillors were told the original bridge budget was based on an outline design, before detailed hydraulic modelling was carried out and before details of the land developments in the area were known.

The final modelling required a bridge roughly twice the size of the outline design.

The tendered price, costs to date, increased hydraulic modelling at the regional council's request, the professional services required for the monitoring, surveillance and quality assurance of the bridge's build, amount to about $5.1 million.

The existing budget of $3.4 million formed part of the consultation undertaken for the 2015/2025 Long Term Plan.

There was $100,000 budgeted in 2015/16 and $3.3m budgeted for 2016/17.

The bridge will cross the Kopurererua Stream at the roundabout on SH36 and will connect the Tauriko Business Estate to the highway.

Construction is scheduled for the current financial year.

Tauranga's fast growth rate since the GFC has brought projects forward and there was insufficient time and resources to plan and cost projects particularly where they are complex or one-off projects, says the staff report. Additional resources are currently being recruited and a number of improvement initiatives are being implemented.

The project is development contribution funded. Because some of the growth in the development contribution catchment for this project has already occurred, about $600,000 of the costs will need to be funded by way of rate funded debt.