watercare只负责wastewater and water supply, stormwater是隶属auckland council 负责,根watercare没有关系。根据你区域的地质,有可能是onsite soakage。kerb outlet可不可行需要具体看,i.e.你具体要做什么development,马路上附近有没有catchpit,有没有flood plain。kerb outlet的话一般是需要做水箱的,当然还是要看你具体做什么。
public stormwater extension做起来比较耗时耗资金,但是有时候council会硬性要求。需要做engineering plan approval,QA (as-built plan, vested assets, completion certificate, etc)