Evaluating the potential of constructed groundwater systems to improve the water supply operations of Auckland City, New Zealand
type: CreativeWork
description: A range of constructed groundwater systems are evaluated for augmenting the potable water supply of Auckland City, New Zealand. The term ‘constructed groundwater systems’ encompasses any constructed means of recharging or extracting water from an aquifer. This may for example include infiltration wells and basins, injection wells, aquifer storage and recovery wells, and horizontal wells. The study motivation is to increase the sustainable yield from Auckland’s existing groundwater resources to help meet Auckland’s increasing water demand. Presently, 97% of the water supply comes from 10 storage reservoirs in the Hunua and Waitakere Ranges, and up to three percent from the Onehunga - Mt Wellington aquifer. The Onehunga - Mt Wellington aquifer is a highly fractured basalt aquifer and has the potential to store water in its unsaturated zone. Various methods of artificially increasing the recharge of the Onehunga - Mt Wellington aquifer to increase its sustainable summer yield were investigated using a FEMWATER numerical model. Three sources of recharge water were identified in the Auckland Region: winter spillage from Watercare’s 10 reservoirs, groundwater from the dewatering of the Three Kings quarry, and wastewater from the Mangere Wastewater Treatment Plant. Artificial storage and recovery (ASR) wells, and soakage wells were simulated as a means of increasing the aquifer’s yield. The greatest simulated increase in yield was from winter injection of reservoir water via ASR wells, in conjunction with the summer extraction of the stored reservoir water. This simulation resulted in the average summer aquifer yield increasing from 9,100 to 44,100 cubic metres per day. A hydrogeological review of the both the Hunua and Waitakere Ranges showed that there is little opportunity for utilising constructed groundwater systems below the regolith zone in those two locations. However, the storage capacity of the unconfined aquifers in the regolith layer of the Waitakere and Hunua …
abstract: A range of constructed groundwater systems are evaluated for augmenting the potable water supply of Auckland City, New Zealand. The term ‘constructed groundwater systems’ encompasses any constructed means of recharging or extracting water from an aquifer. This may for example include infiltration wells and basins, injection wells, aquifer storage and recovery wells, and horizontal wells. The study motivation is to increase the sustainable yield from Auckland’s existing groundwater resources to help meet Auckland’s increasing water demand. Presently, 97% of the water supply comes from 10 storage reservoirs in the Hunua and Waitakere Ranges, and up to three percent from the Onehunga - Mt Wellington aquifer. The Onehunga - Mt Wellington aquifer is a highly fractured basalt aquifer and has the potential to store water in its unsaturated zone. Various methods of artificially increasing the recharge of the Onehunga - Mt Wellington aquifer to increase its sustainable summer yield were investigated using a FEMWATER numerical model. Three sources of recharge water were identified in the Auckland Region: winter spillage from Watercare’s 10 reservoirs, groundwater from the dewatering of the Three Kings quarry, and wastewater from the Mangere Wastewater Treatment Plant. Artificial storage and recovery (ASR) wells, and soakage wells were simulated as a means of increasing the aquifer’s yield. The greatest simulated increase in yield was from winter injection of reservoir water via ASR wells, in conjunction with the summer extraction of the stored reservoir water. This simulation resulted in the average summer aquifer yield increasing from 9,100 to 44,100 cubic metres per day. A hydrogeological review of the both the Hunua and Waitakere Ranges showed that there is little opportunity for utilising constructed groundwater systems below the regolith zone in those two locations. However, the storage capacity of the unconfined aquifers in the regolith layer of the Waitakere and Hunua …
author: Brown, Edmund
license: https://researchcommons.waikato.ac.nz/bitstreams/eda83d73-6b85-4807-8c5c-6447c9eebcb3/download
date published: 2002
date modified: 2026-07-24T05:57:46Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato