This is a pretty solid request for a cycle link between the end of the Clutha Gold and Dunedin:
It is also the evolution of this:
https://mk2.betterstreets.nz/t/taeiri-plains-trails-propsal/94
Here is an update to this project (behind the usual ODT paywall)
In summary, there is lots of interest, it is likely to be expensive, and will start at the Mosgiel end.
Finger crossed the $$$ flow!