Residents will no longer be able to access the river reserves from the western and eastern ends on Eunony Bridge Road with the closure of the road and fencing installed either side of the bridge.

The council's commercial operations director Caroline Angel said the specialised equipment required for $10.6 million upgrade was stolen between Tuesday night and Wednesday morning causing delays to the project less than a week into the full closure of the bridge.

She said the theft was disappointing from so many perspectives.

"Acts such as these impact everyone - the council, the contractors and the general public all suffer as a consequence of these unlawful actions," she said.

"Security will now be tightened at the work site and access will be restricted in those areas around the bridge. It means closing a large section of Eunony Bridge Road, particularly to prevent vehicles accessing the area.

"The equipment that was stolen was quite large and required a vehicle and effort to move.

"As a direct consequence of this theft, costs incurred by additional security measures and the equipment replacement will all roll into the project. They're additional costs that are unnecessary and they impact on the project."

Ms Angel said the contractor was working quickly to get replacement equipment so work could resume as soon as practicable.

The approaching road from the eastern side of Eunony Bridge Road will now be closed at the intersection of Gumly Road.

The bridge will be closed until August 1.