title: Evaluating the potential of constructed groundwater systems to improve the water supply operations of Auckland City, New Zealand

authors: Brown, Edmund

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 Ranges could potentially be used to increase the efficiency of the existing water supply reservoirs presently losing water to seasonal spillage.

To increase the efficiency of the existing water supply reservoirs it is proposed that horizontal wells can be used to control the water table elevation in the reservoir catchments, permitting a degree of control over the discharge of the streams flowing to the reservoirs. The use of horizontal wells provides a range of control options, including increasing stream discharge during summer and reducing and delaying peak discharges from rainfall events during winter. The use of horizontal wells in this manner is most suited to catchments where the magnitude of stream quickflow discharge is dependent on the depth of the surrounding water table. That is, for similar-sized rainfall events, a water table near the ground surface results in more quickflow stream discharge compared to a deeper water table.

The Upper Nihotupu water supply reservoir catchment in the Waitakere Ranges was selected as a study site to gather hydrological data to simulate use of horizontal wells. In the Upper Nihotupu catchment, there is a fourfold increase in quickflow discharge for similar sized rainfall events for a water table 0.5 m below the ground surface, compared to a water table 2.7 m below the surface. Based on this, a MODFLOW numerical groundwater model was utilised to simulate the operation of hypothetical horizontal wells within the Upper Nihotupu catchment, and to evaluate if the manipulation of stream discharge will increase the reservoir’s storage capacity. Simulation results suggest there is potential for a significant increase in summer stream flow by draining the surrounding aquifer with the horizontal wells. During the 30 day period that the wells are draining the aquifer, the corresponding average reservoir delivery increased from 10,000 to 25,000 cubic metres per day. During the winter, the draining of the aquifer using horizontal wells results in reduced and delayed quickflow stream discharge. This in turn resulted in less spillage from the Upper Nihotupu reservoir. The increased control of the stream hydrograph by the simulated horizontal wells increased the average annual delivery of water from the Upper Nihotupu reservoir by seven percent.

text: Evaluating the potential of constructed groundwater systems to improve the water supply operations of Auckland City, New Zealand 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 Ranges could potentially be used to increase the efficiency of the existing water supply reservoirs presently losing water to seasonal spillage.

To increase the efficiency of the existing water supply reservoirs it is proposed that horizontal wells can be used to control the water table elevation in the reservoir catchments, permitting a degree of control over the discharge of the streams flowing to the reservoirs. The use of horizontal wells provides a range of control options, including increasing stream discharge during summer and reducing and delaying peak discharges from rainfall events during winter. The use of horizontal wells in this manner is most suited to catchments where the magnitude of stream quickflow discharge is dependent on the depth of the surrounding water table. That is, for similar-sized rainfall events, a water table near the ground surface results in more quickflow stream discharge compared to a deeper water table.

The Upper Nihotupu water supply reservoir catchment in the Waitakere Ranges was selected as a study site to gather hydrological data to simulate use of horizontal wells. In the Upper Nihotupu catchment, there is a fourfold increase in quickflow discharge for similar sized rainfall events for a water table 0.5 m below the ground surface, compared to a water table 2.7 m below the surface. Based on this, a MODFLOW numerical groundwater model was utilised to simulate the operation of hypothetical horizontal wells within the Upper Nihotupu catchment, and to evaluate if the manipulation of stream discharge will increase the reservoir’s storage capacity. Simulation results suggest there is potential for a significant increase in summer stream flow by draining the surrounding aquifer with the horizontal wells. During the 30 day period that the wells are draining the aquifer, the corresponding average reservoir delivery increased from 10,000 to 25,000 cubic metres per day. During the winter, the draining of the aquifer using horizontal wells results in reduced and delayed quickflow stream discharge. This in turn resulted in less spillage from the Upper Nihotupu reservoir. The increased control of the stream hydrograph by the simulated horizontal wells increased the average annual delivery of water from the Upper Nihotupu reservoir by seven percent.

year: 2002

title: Democracy without voting

authors: Munn, Nicholas

subjects: Democracy

abstract: Both epistocrats and lottocrats claim that democracy itself is problematic. They set themselves the task of providing a plausible alternative system. However, many of the problems they identify arise not from democracy as such, but from certain instantiations of it. When and how people vote; how many people choose not to vote; and how much the people who do vote know, are all subjects of criticism in this literature. In this paper I outline a democratic system which retains features such as majority rule and secrecy regarding the expressed preferences of citizens, but eliminates voting. I argue that this approach can achieve many of the benefits ascribed to epistocratic or lottocratic systems without importing their flaws.

text: Democracy without voting Both epistocrats and lottocrats claim that democracy itself is problematic. They set themselves the task of providing a plausible alternative system. However, many of the problems they identify arise not from democracy as such, but from certain instantiations of it. When and how people vote; how many people choose not to vote; and how much the people who do vote know, are all subjects of criticism in this literature. In this paper I outline a democratic system which retains features such as majority rule and secrecy regarding the expressed preferences of citizens, but eliminates voting. I argue that this approach can achieve many of the benefits ascribed to epistocratic or lottocratic systems without importing their flaws.

year: 2019

title: River Co-management and Planning in the Waikato: An Analysis of Regional and District Plans and Regional Policy Statement Compliance, and a New Approach to Plan Preparation

authors: den Ouden, Hester

subjects: co-management

abstract: The Waikato River is one of New Zealand most significant rivers.  It is an ancestor to one Iwi, significant to four other Iwi generates most of the country’s hydroelectricity and provides large amount of potable water to municipalities.
In 2010 and 2012 three Acts of parliament established the framework for the restoration and protection of the Waikato River Catchment.  It did so in three ways.  The River Co-Management Legislation (RCML) has significantly added to the policy framework under the Resource Management Act 1991 for the Waikato Regional and six Districts.  It introduced the requirement for co-management of decision-making at policy and regulatory approvals, and established the Waikato River Authority which manages a $270 million Clean-Up fund.
This research outlines the provisions of the three statutes that comprise the RCML, how legislation changed the hierarchy of the planning framework, and identifies areas where improvements could be made.  
The RCML introduces a ‘Vision and Strategy’ as a National Policy Statement for the area of the region within the Waikato River Catchment.  The ‘Vision and Strategy’ comprises 13 statements that are the Vision and 12 statements that are the strategy, collectively referred to as stratagems.  The research assesses each plan and policy statement within the Waikato River catchment to determine the nature and level of incorporation of the 25 stratagems of ‘Vision and Strategy’.
A new approach in planning is the requirement for the use of Maatauranga Maaori along with western science, the Māori and western science worldviews.  These worldviews are discussed.  Three Models that use Maatauranga Maaori principles are described.  The purpose of this has been to begin a discussion on the basis of another perspective in future plan and policy making that included better provisions based on the Maatauranga Maaori worldview.
The Planning Under a Co-operative Mandate (PUCM) project assisted in identify criteria against which to assess the regional and district plans and regional policy statement, their quality, comprehensiveness of inclusion of the ‘Vision and Strategy’ stratagems, and the required cascading nature of Objective policies and methods that are contain in the plans and regional policy statement.   
Key findings were that the provisions or inclusion of the ‘Vision and Strategy’ Stratagems was mixed, high in the case of scientifically quantifiable matters and poor and non-existent where matters to be included were less able to be quantified and qualified in a western science worldview.  The strengths and weakness of including the ‘Vision and Strategy’ Stratagems varied and the strength of that inclusion was identified.
A consequential finding was the overall quality of the plans themselves.  The first PUCM report to government in 2001 on plan quality, scored all six districts and regional plans below 50%.  Using PUCM project criteria to assess the degree to which the Stratagems were included in the plans in 2016 showed a similar result.  The consequential findings also found confusion over the nature of good objective, policy and method drafting.  It also found significant lack of cascading from objectives through policies to methods.

text: River Co-management and Planning in the Waikato: An Analysis of Regional and District Plans and Regional Policy Statement Compliance, and a New Approach to Plan Preparation The Waikato River is one of New Zealand most significant rivers.  It is an ancestor to one Iwi, significant to four other Iwi generates most of the country’s hydroelectricity and provides large amount of potable water to municipalities.
In 2010 and 2012 three Acts of parliament established the framework for the restoration and protection of the Waikato River Catchment.  It did so in three ways.  The River Co-Management Legislation (RCML) has significantly added to the policy framework under the Resource Management Act 1991 for the Waikato Regional and six Districts.  It introduced the requirement for co-management of decision-making at policy and regulatory approvals, and established the Waikato River Authority which manages a $270 million Clean-Up fund.
This research outlines the provisions of the three statutes that comprise the RCML, how legislation changed the hierarchy of the planning framework, and identifies areas where improvements could be made.  
The RCML introduces a ‘Vision and Strategy’ as a National Policy Statement for the area of the region within the Waikato River Catchment.  The ‘Vision and Strategy’ comprises 13 statements that are the Vision and 12 statements that are the strategy, collectively referred to as stratagems.  The research assesses each plan and policy statement within the Waikato River catchment to determine the nature and level of incorporation of the 25 stratagems of ‘Vision and Strategy’.
A new approach in planning is the requirement for the use of Maatauranga Maaori along with western science, the Māori and western science worldviews.  These worldviews are discussed.  Three Models that use Maatauranga Maaori principles are described.  The purpose of this has been to begin a discussion on the basis of another perspective in future plan and policy making that included better provisions based on the Maatauranga Maaori worldview.
The Planning Under a Co-operative Mandate (PUCM) project assisted in identify criteria against which to assess the regional and district plans and regional policy statement, their quality, comprehensiveness of inclusion of the ‘Vision and Strategy’ stratagems, and the required cascading nature of Objective policies and methods that are contain in the plans and regional policy statement.   
Key findings were that the provisions or inclusion of the ‘Vision and Strategy’ Stratagems was mixed, high in the case of scientifically quantifiable matters and poor and non-existent where matters to be included were less able to be quantified and qualified in a western science worldview.  The strengths and weakness of including the ‘Vision and Strategy’ Stratagems varied and the strength of that inclusion was identified.
A consequential finding was the overall quality of the plans themselves.  The first PUCM report to government in 2001 on plan quality, scored all six districts and regional plans below 50%.  Using PUCM project criteria to assess the degree to which the Stratagems were included in the plans in 2016 showed a similar result.  The consequential findings also found confusion over the nature of good objective, policy and method drafting.  It also found significant lack of cascading from objectives through policies to methods.

year: 2017