Author(s): Costel Mustatea; Naresh Singhal; Gregory De Costa
Keywords: –salinity intrusion
Abstract: Waiwhetu aquifer which is a significant source of water for the Wellington region is susceptible to salinity intrusion. This research endeavored to model the aquifer using PMWIN model, and then investigate non conventional methods to monitor and manage salinity intrusion. In addition to the conventional Abstraction control technique the effect of recharge on salinity intrusion is analyzed, by investigating controlled river floods, use of river banks and water traps, use of infiltration basins and injection wells. It has been shown that with a combination of low impact development techniques i.e. infiltration basins, water traps, injection wells, abstraction could be doubled without a risk of salinity intrusion. The result of the simulations shows that the risk of sea water intrusion can not be reduced only by controlling the level of abstraction particularly if demand continues to increase and recharge decrease, but augmentation of recharge is a superior and viable alternative which facilitates abstraction as well.