For the landowners along Duck Creek, restoring the stream to its former glory has been a labour of love. First, the mature pine trees along the banks were removed, then native seedlings planted and other weed species managed. The icing on the cake was to remediate a perched, box culvert on the stream that was preventing migratory native fish from accessing wetland habitat upstream. 

The landowners made two previous attempts to create fish passage up the culvert but high flows during flood events destroyed their hard work.  Thanks to funding from Auckland Council Healthy Waters, and through the Whitebait Habitat Restoration Project managed by the Whitebait Connection, this barrier has now been fixed.

Riffle Restoration was employed to remediate the culvert by installing a fish ‘ladder’ and muscle rope on the downstream edge, which allows climbing and strong swimming species to navigate their way upstream. Baffles were also placed inside the culvert, to create resting places for tired fish.

A fish survey undertaken since the fish ladder was installed found juvenile banded kōkopu and bully species above the culvert, and whitebait resting behind the baffles in the culvert. This is great news for the landowners, the Whitebait Connection and the fish, who now have 2kms of extra waterway to explore.

Nelson City Council has recently explored a new method of inspecting culverts with the use of a drone.

Below is footage highlighting the improvement to fish passage after fish baffles were fitted, with increased depth, lower velocity and rest pools throughout.

Based on recent results, the outcomes for fish passage are promising.