Plans for a new green bridge brought to the Brisbane City Council this week have derailed plans for a superyacht mooring site under Kangaroo Point Cliffs.

The state government announced a 12-month trial allowing superyachts to dock opposite the City Botanic Gardens In March last year.

The new bridge is set to be suspended 12.7 metres, blocking 37 metre high super yachts from mooring along the cliffs.