No.1 Drain is a 480-metre drain located in the Shirley Links Golf Course. The drain suffered extensive earthquake damage. Further failure could result in an increased flood risk and repair is needed to ensure the drain keeps functioning.

No 1 Drain works completed

No.1 Drain is being repaired through naturalisation, which means the concrete channel is replaced with natural earth banks and planted.

This will bring improved capacity to the waterway, and improve its ecological health with the formation of new habitats and shading of the waterway. In addition to the repair, a stormwater treatment pond is being added to the drain to improve the quality of water discharged into Waikākāriki/Horseshoe Lake.