Brisbane City Council announced plans last year to widen the cycleway due to its high popularity, and improve its protection against flooding.

Linking the ferry terminal and Brisbane Powerhouse to the new river hub, where private ferry operators will also be able to dock, the walkways have been cordoned off in sections over the past few months while works continue.

The flat sections of the park closest to the river are now partially closed off while concrete pathways are refurbished, including the new 4.5-metre-wide cycleway and promenade.

A council spokeswoman said fencing along the pathway was moved as the project progressed.

"Council is delivering this project to ensure New Farm Park remains one of Brisbane’s most treasured parks and continues to offer an array of popular facilities to be enjoyed all year round," she said.

"Stage One was completed in late 2018 and delivered a footpath to the park.

"Stage Two and Three are currently under way with a connection between Brisbane Powerhouse and the park being built."

The promenade along the river's edge will also have new landscaping, lighting and seating as part of the upgrades.

The council spokeswoman said every effort was made to minimise disruption while the works continue until mid-2019.