Planning for water allocation
Abstract
An important component of water management is the planning of water allocation from rivers and groundwater resources. In terms of RMA planning, water policy may be established at a number of levels from, national policy statements (potentially), regional policy statements (necessarily), and regional and district plans (optionally). In addition, water allocation plans can help to provide very important frameworks for managing the take and use of water from rivers, lakes, or aquifers.
This guidance note addresses the complex area of allocating water resources from rivers and groundwater including the utilisation of water allocation plans for an integrated water planning framework. Reference is also made to relevant publications, best practice examples, and current challenges in practice.
Guidance note
Introduction
Water is perhaps our most important resource, providing a fundamental requirement for sustaining life and economic production. Water allocation planning is, therefore, a large and complex subject that ranges from strategic considerations such as establishing land uses that are compatible with the available water resource, to site specific issues associated with individual water takes. Water allocation cannot be separated from water quality (for example, the downstream effects of land use intensification) and the management of the beds and margins of water bodies.
Water allocation planning is a multi-disciplinary process that requires diverse skills and detailed information. Minimum flows and levels for rivers, lakes and aquifers protect their environmental values. Allocation limits establish the amount of water that can be taken and manage the relationship between accessibility and reliability of supply. Restrictions on takes reduce the amount of water being used when the water reaches the minimum flow or level. These management controls enable councils to address the cumulative environmental effects of water take and use. They also help ensure the water supply is reliable and access to it is equitable.
Technical methods are required to establish a 'flow or level regime ' that protects environmental values and to analyse the quantity and reliability of the resource. The technical details should not obscure the fundamental issue, the relationship between environmental protection and resource availability. Transferring data from one river, lake, or aquifer to another with similar characteristics allows a regional approach to water quantity planning. However, most water quantity plans apply to specific catchments.
Sustainable Water Programme of Action
The Sustainable Water Programme of Action is a Government programme established in 2003 to ensure freshwater resources are managed and used in ways that support New Zealand 's long-term sustainable development. It is jointly led by the Ministry for the Environment and the Ministry of Agriculture and Forestry.
While water management is always difficult, trends now indicate that there are shortcomings in New Zealand 's freshwater management framework. In the face of competing demands and uses for water, New Zealand needs a more sophisticated, flexible and innovative framework. The Sustainable Water Programme of Action acknowledges these needs and has identified three national outcomes for freshwater:
Possible actions in each of these areas have been proposed. Freshwater for the Future: A supporting document outlines these actions in greater detail.
The importance of plans for managing water allocation
Water is a public good of high value and limited supply. Under s14 RMA the taking of water from rivers, lakes and aquifers (groundwater) must either be authorised by consent or hold a permitted activity in a plan (this excludes the taking of water for stock drinking and domestic purposes, which are specifically permitted by s14). Water takes may not be well managed by individual consents because the effects on the environment and on resource availability and reliability are cumulative. Consequently, water allocation plans provide a framework for managing water abstractions (takes) from rivers and groundwater. A good management framework enables regional councils and unitary authorities to:
Water allocation plans are mostly concerned with managing the cumulative effects of consumptive use. Consumptive, as opposed to instream, use is the use of water from a river, lake, or aquifer that does not result in the water being returned to its source (for example, water used for irrigation or urban supply), thereby reducing the water flow or level. However, this guidance note can also apply to all out of stream use.
Out-of-stream use [Reveal/Hide]
Out-of-stream use includes activities that dam and divert water and then return it to another location, such as hydro-generation. Many points covered in this note also apply to these activities.
Water allocation plans need to be 'nested ' within the broader policy framework that considers national and regional strategies for sustainable development, the available water resources within a region, community aspirations for the development and environmental management of their area and the reasonably foreseeable demand and conflicts for water. Cumulative effects result from multiple takes of water for consumptive use.
Cumulative effects impact on environmental values, the reliability of supply, and equity for users. As each take reduces the flow or level of the water, it reduces the reliability of supply for water users. In turn, this impacts on equity of use, as the water supply is increasingly unable to meet demand.
Water allocation policy needs to provide a framework that addresses these three matters. Takes must be managed in a way that ensures environmental values are not adversely affected, the share of water take for consumptive use is equitable and understood by users and the reliability of supply is adequate.
Environmental values
Environmental values include those of the river, lake, or aquifer 's role in the ecosystem, its recreational value, its natural character and its cultural and spiritual qualities. Any water allocation planning exercise must start with a thorough understanding of these values. These are usually derived from resource studies and consultation with the community of interest.
In general, environmental values are robust enough that they can potentially be sustained at the same time that some water is taken for consumptive use. However, consumptive use of water can coincide with natural changes in water flow and levels in rivers, lakes, and aquifers and cause adverse effects to environmental values. At times of low river flows or lake and groundwater levels, heavy consumptive use can cause significant reductions in residual flows, with consequent adverse effects on the ecological and other values of the resource. For this reason, management controls in water allocation plans largely focus on periods of naturally low levels and impose minimum flows and allocation limits to sustain instream environmental values and limit the duration of human induced low flow conditions.
Figure 1: Water flows and levels
Text description of figure:
A hydrograph for a river showing the natural flow amount of a river and the reduced
residual flow due to the abstraction rate. The hydrograph shows the
effect of imposing a minimum flow on reliability. The abstraction rate (the difference
between the natural flow and reduced residual flow) varies over time to ensure that the nominated minimum flow (here 600 l/s) is met. Note that the natural flow does descend below the minimum flow at
one point.
Rivers, in particular, can be put under considerable stress during periods of summer low flow. Heavy consumptive use during this time can make river ecosystems unsustainable. Allocation can also change the flow variability or the general pattern of flow over the year and includes 'flushing ' flows, for instance, to 'flush ' the river system of sediment and algae. While flow variability is part of the natural character of rivers, extended periods at very low flows are unnatural.
In sensitive aquifers and waterways, such as spring-fed waterways and aquifers with 'fossil ' groundwater, multiple takes can cause adverse effects even at normal flows and levels.
Water allocation plans may also need to address the environmental effects of the use of water. For example, irrigation can lead to leaching of nutrients into groundwater. Consumptive use may also need to be managed in terms of application rates to avoid these 'downstream ' effects.
Reliability and equity issues
'Reliability ' usually means the amount of time that users have access to the water supply. The principle of equity suggests that water should be allocated to all who want it. However, maximising access to water can result in a reduction in the reliability of supply, due to increased demand.
Reliability of supply [Reveal/Hide]
Reliability of supply means the ability of the river, lake or aquifer to provide sufficient water for consumptive use when it is needed. Allocation limits aim to achieve an acceptable balance between accessibility and reliability of supply.
The more accessible water is, the less reliable its supply will be. Allocation limits are set to establish an acceptable balance between reliability and accessibility of water supply for a group of users. Consideration of equity should also extend to considering 'reasonable use '. Accessibility can be improved by ensuring water is allocated to users in quantities that are reasonable for the intended use, and by promoting water conservation. This ensures the resource can be shared as widely, equitably and efficiently as possible.
Types of water allocation plan
Ideally water allocation is managed for single catchments or aquifers. There may be sufficient information to carry out a thorough assessment for a specific catchment or aquifer. In this case a specific plan can be developed that is certain and justifiable.
A region-wide plan can have the advantage of being more strategic than a specific catchment or aquifer plan. For example, a region wide plan may be able to consider land use potential and establish strategies for managing increased demand for water. However, region-wide plans can also be less certain and justifiable because of inadequate region-wide data. One solution to the problem of inadequate data is regionalisation.
Regionalisation
Regionalisation involves transferring hydrological data from rivers and groundwater resources where flow has been measured to rivers and groundwater sites where flow has not been measured. It can be used to transfer minimum flows and allocation limits between catchments.
This transfer is most reliable and successful when it is done between catchments with similar characteristics such as climate, geology, and topography. It helps make water quantity planning within regional plans more certain and justifiable.
A new approach to regionalisation is the River Environment Classification (REC). REC is based on the important factors determining hydrological and hydraulic behaviour of rivers. It allows rivers to be linked to environmental values, and to minimum flows required for their protection. In addition, the management framework approach uses the REC as a spatial framework for developing regional plans.
Developing a water allocation plan
A water allocation plan must:
Developing a water quantity plan is a complex, multi-disciplinary task that requires technical information and knowledge of stakeholder values and expectations. The planning practitioner 's role is to integrate these skills and information to develop policies that achieve an acceptable trade-off between environmental sustainability and water use in terms of section 5 RMA. This generally involves the following steps:
Identify the skills and people you need
Developing an effective water quantity plan requires the input of different technical skills, including: hydrologists, ecologists, landscape experts, experts in Maori values, and specialists in water use (such as irrigation).
Gather the information
Water quantity planning requires detailed information.
Collect:
Identify:
Assessment of options
Management options that are developed should be based on an analysis of the information gathered and should include:
Instream flow regime and minimum flow
An instream flow regime is set to ensure that the effect of consumptive use of water during naturally low flows, as well as the effect of use on flow variability, does not adversely affect the water resource.
A minimum flow is an essential part of an instream flow regime and sets a minimum 'level of protection ' for environmental values. Allocation restrictions are imposed when the river reaches its minimum flow level because of water takes or because of natural flow change. Water takes are banned altogether when the natural flow goes below the minimum flow. It may be that an assessment shows that minimum flows are not required because foreseeable demand is unlikely to affect environmental values.
There will often be an environmental value that is most affected by low flow conditions, i.e. the baseline value. This is the logical value to use for setting minimum flows.
A range of techniques is available to derive minimum flows. Minimum flows are generally derived by considering the hydraulic implications of a flow on a value. For example, Instream Flow Incremental Methodology (IFIM) techniques can describe how the hydraulic habitat of fish changes with flow. In some circumstances, such as considering the effect of flow changes on natural character, it will be useful to present the various options to stakeholders. The information can be presented in an easily understood way by illustrating the effect of different flows on hydraulic conditions. For more complex or detailed assessments, water levels can be superimposed on photographs of river channels. Hydraulic modelling and GIS can be used to provide three dimensional and animated presentations of the effects of different flow regimes.
Hydraulic variables [Reveal/Hide]
Water depth, velocity and width are known as hydraulic variables. A change in river flow, or a take from or return of water to an aquifer, changes the, hydraulic conditions. Hydraulic changes are the immediate cause of environmental effects of water use. Hydraulic modelling examines the relationships between water depth, velocity and width with changes in flow.
Setting minimum flows and levels [Reveal/Hide]
Refer to 'Flow Guidelines for Instream Values ' (MfE, 1998) for the technical methods for setting minimum flows and levels. Technical experts have differing opinions about the right way to set minimum flows and flow regimes. This can cloud the resource management issues you need to focus on. Refer 'Current challenges in practice '.
An instream flow regime may also incorporate other aspects of the flow regime such as maintaining flow variability. An aspect of flow variability that should be considered is the need to ensure occasional higher flows that are able to 'flush ' the riverbed of accumulated algae and sediment.
A minimum flow can also be used to manage aquifer levels when the aquifer is directly connected to the river.
Figure 2: Suitability versus flow
Text description of figure:
The chart shows a graph of the suitability of a river of a river for a particular use versus the amount of its flow. The suitability of a river for a given value (e.g. trout habitat) varies in a complex way.
The suitability (or the 'level of protection ' for a value) will generally initially rise
quickly from zero at a flow of zero to a maximum value at which point the level of
protection may decline or stay uniform. See 'Flow Guidelines for Instream Values '
(MfE, 1998) for examples of these relationships.
Minimum aquifer or lake level
The minimum level sets a 'bottom line ' level for groundwater. Allocation restrictions are imposed when the lake or aquifer reaches its minimum level because of water takes. Water takes are banned altogether when the natural lake or aquifer goes below its minimum level. Minimum aquifer levels are usually set to protect against saltwater intrusion, and to ensure that levels are not reduced below the depth of existing bores.
Allocation limit
The allocation limit is the maximum rate that water can be taken from a river or total the volume that can be taken from a lake or aquifer in a year. The purpose of an allocation limit is to limit the impact on instream values and to establish an acceptable balance between reliability and accessibility. They should:
Reallocation can occur as consents terminate or can occur strategically by way of policy review. Options include:
Note: Changes introduced by the 2005 amendment to the RMA will give priority to the renewal of existing consents over competing activities unless a regional plan reallocates water resources prior to their expiry. These changes come into force on 10 August 2008 (refer to RMA provisions for further information).
Priority regimes for take restrictions
A priority regime establishes how water takes from a river, lake, or aquifer are to be restricted when it is close to its minimum flow or level. A priority regime can be specified in a regional plan and implemented through consent conditions. Priority regimes can be established once minimum flows/levels, and allocation limits have been determined.
Types of priority regime are: prior appropriation, pro-rata cutback, and priority bands.
How to assess options for minimum flows, minimum levels, allocation limits, and priority regimes for take restrictions
Because natural flows are highly variable, assessments are generally made by evaluating various 'options ' for management. Combinations of minimum flows, levels and allocation limits are superimposed on 'natural ' historic or modelled flow or level data. From this analysis the behaviour of the residual flows, groundwater levels and the reliability of supply can be expressed as statistical values. It is assumed that these values will remain the same in the future provided that other catchment conditions stay constant. It is, however, a good idea to include a risk analysis of how each option would perform under conditions of change in, for example, climate and catchment land use. Similar types of analyses using aquifer models are performed for groundwater resources.
The statistical information is then carried forward to the consultative and decision-making process, to help inform the selection of a specific option.
It is generally best to carry out an assessment of options that are to be used as part of stakeholder consultation. This allows the trade off between environmental protection and resource availability to be clearly understood and discussed. It may be best to hold an initial round of consultation before generating options to canvass the communities ' views on values and expectations for water use.
As a part of the minimum flow assessment, establish what the residual flow of the river would be after the entire allocation limit has been taken. The statistical analysis of the residual flow can help to determine if effects other than those caused by 'instantaneous ' low flows are a concern. For example, if allocation is high, residual flows can be 'dragged down ' to near the minimum for long periods of time. This can cause effects such as excessive algal growth due to low water velocity or loss of natural character due to alteration of the natural variation in flow.
Hydrologists will usually carry out the statistical analysis. Go to the NIWA website for the Low Flow Analysis Tool (LowFAT) software. LowFAT enables a statistical analysis of the river flows that will result from specific allocation limits and minimum flows.
Waitaki Catchment Water Allocation Regional Plan
The Waitaki Catchment, located predominantly in the South Island's Canterbury region, is important both for hydroelectricity and irrigating pasture, as well as for its natural, recreational, community and fishery values. It is also a strategic national asset and a defining feature for Ngai Tahu. Many people, companies and organisations want to use water from the Waitaki River.
Due to increasing demand on this resource, Parliament passed the Resource Management (Waitaki Catchment) Amendment Act in September 2004, to create an improved decision-making process for allocating water from the Waitaki Catchment. This process included the establishment of the Waitaki Catchment Water Allocation Board - an independent statutory body appointed by the Environment Minister.
The Board had 12 months, until the end of September 2005, to develop and approve a water allocation regional plan for the Waitaki Catchment.
The Waitaki Catchment water allocation plan is a regional plan under the Resource Management Act. Once outstanding appeals to the High Court have been resolved, Environment Canterbury (Canterbury Regional Council) will administer the final plan. The Waitaki Catchment Water Allocation Board will be dissolved.
Create a monitoring strategy
Provisions to monitor the effect of water takes on rivers, lakes, and aquifers are an essential part of a water allocation plan. The monitoring regime should attempt to fill information gaps, and test assumptions made in the course of plan preparation. For example:
Best practice examples
A catchment plan that has developed both allocation limits and minimum flows is:
- Marlborough District Council's Proposed Wairau/Awatere Resource Management Plan
Setting minimum flows in a region-wide plan is difficult because of the number of rivers involved and the technical difficulties associated with minimum flow setting. Two plans that have made good use of methods for regionalisation of minimum flows are:
Horizons Regional Council has prepared a draft water allocation plan change to their Land and Water Regional Plan (September 2004) in preparation for the proposed merging of seven regional plans into One Plan for the Manawatu-Wanganui region. Much existing policy for water management will be retained and refined, with new policy developed from current council research programmes to identify management zones, sustainable yields for groundwater, minimum environmental flows and the volume available for allocation to water users from each river in the catchment.
The proposed water chapters in Environment Canterbury 's Natural Resources Regional Plan include a specific chapter dealing with water quantity which aims to increase environmental flows and maintain reliable irrigation. This includes raising the minimum flow of the Ashburton River allowing increased takes for irrigation during the winter and spring months thereby ensuring a more reliable take during the spring growth period.
Environment Canterbury has also produced guidelines on groundwater allocation limits for the Canterbury Region.
RMA provisions
Many sections of the RMA are relevant to the broad area of water policy. In particular, Section 9 and Section 31 provide for the control of effects the use of land on water quantity and control the use of land for the maintenance of water quantity in district plans.
With respect to allocation planning in particular, Section 14 of the RMA prohibits unauthorised taking, damming and diversion of water. Part V (particularly those sections relating to Regional Plans), is also relevant. Councils also need to take into account their duties and functions under Section 35, due to the complexity of managing water quantity.
Section 30 as amended, 10 August 2005 clarifies that a regional Council's functions include the establishment of rules in a regional plan to allocation natural resources including water (other than open coastal water).
Subject to Part 2 of the RMA, a plan can allocate resources amongst competing activities. However, it cannot include rules that reallocate a resource that is subject to existing resource consents. This does not affect s Council's powers to set minimum or maximum flows under section 68(7) of the Act. Plans are not required to allocate the relevant resource in the way that reflects existing consents and plans do not have to anticipate applications for new consents to replace expiring ones. Therefore, plans can set rules that provide for reallocation of the resource when existing consents expire.
Section 104A requires consent authorities to have regard to the value of existing investment when determining applications for new consents to replace existing consents. This requirement only applies to applications made under section 124 of the Act, that is, where the existing consent holder applies for a new consent for the same activity and the application is made at least three months before the expiry of the existing consent.
New sections (sections 124A-124C) set up a process to give existing consent holders priority over new applications when an existing consent holder applies for a new consent to replace its existing consent. The process is a default position that can be changed by the regional plan. The default rule will not come into force until three years after the commencement of the Amendment Act. The intention is to allow regional councils to consider the issue of natural resource allocation and to change a regional plan to vary the default rule, where the council considers it appropriate.
Section 124A(2) allows councils to override the default rule by creating an allocation plan or by having a plan that expressly states that sections 124BA-124C of the RMA do not apply. Councils may change or vary their plans in accordance with Schedule 1 to include new provisions if they decide to vary the default rule.
Section 124B sets out additional factors that must be considered by a consent authority in determining applications from existing consent holders that have been afforded priority under. Those factors are:
Section 124C provides that where the consent authority grants the application for the existing consent holder, then the other applications lapse to the extent that the use of the resource has been granted to the existing consent holder.
Section 136 clarifies that water permits can be transferred in whole or in part and for limited periods.
Part 9 Water Conservation Orders
Section 329 Water shortage directions
Case law
Case law under the RMA has established that competing resource consent applications for to the same resource are to be dealt with in order, on a "first come, first served" basis. The RMA requires each applicant's application or applications to be determined on their own merits. It does not allow for a comparative assessment of competing claims to the same resource.
Very few major cases relate to water allocation provisions in plans, although a number of cases relate to water take consent conditions. These individual cases are not particularly relevant to water allocation planning because they do not consider cumulative effects, a central focus of allocation plans.
The Environment Court decisions on the Otago Regional Water Plan, C71/2002 and C792002, set important precedents for designating minimum flows in situations where a historic flow is used to define the minimum (e.g. the mean annual or five year - seven day low flow). The judgement considered that a statistical quantity may change over time and therefore is uncertain and the preference is for a fixed scheduled flow.
Related guidance notes
The following guidance notes are related:
Relevant publications
Water Programme of Action: Potential Water Bodies of National Importance
Published by Ministry for the Environment - July 2004
This paper outlines methodologies to identify water bodies of national importance for a range of values including irrigation.
Water Programme of Action: Water Allocation and Use
Published by Ministry for the Environment - June 2004
This paper identifies problems in New Zealand’s current systems of water allocation and use. It considers various allocation approaches.
Groundwater Allocation Limits: Guidelines for the Canterbury Region Report No. U04/02
Published by Canterbury Regional Council - January 2004
Determines methods of estimating groundwater allocation limits, and their application to the Canterbury Region, where there has been a significant increase in groundwater usage over recent years.
Future Water Allocation Issues
Published by Ministry of Agriculture and Forestry - 2001
This article explores the surrounding management of water allocation under the RMA in New Zealand.
Low Flow Analysis Tool (LowFAT 1.03) User Manual
Published April 2001
Low Flow Analysis Tool software assists in management regime simulation for both instream & out-of-stream river resources, allowing testing of different flow management policies & consent conditions.
Flow Guidelines for Instream Values
Published 1998
These guidelines provide a consistent approach to setting minimum flows and other flow requirements in rivers.
New Zealand River Environment Classification User Guide
Published by NIWA - March 2004
The REC is an ecosystem-based spatial framework for river management purposes, that can be applied at different scales and levels of detail from local to national.
Water Allocation - A Strategic Overview
Published by Ministry for the Environment - May 2001
An overview of water allocation in NZ, to clarify problems with existing practice, and provide strategic level suggestions on improving water allocation and identifying roles & responsbilities.
Relevant websites
Current challenges in practice
Setting minimum flows
A particular issue for practitioners is the need to make a clear distinction between the technical tools used to generate options and the fundamental resource management decisions. A great deal of time can be spent arguing about an appropriate method for setting minimum flows, because they cannot be 'standardised ' in the same way that a water quality standard can. This lack of standardisation provides considerable opportunity for technical debate concerning the way that minimum flows are set. However, this debate should not be confused with the more important resource management decision, which is; what environmental values should be sustained and to what level of protection?
Flexible and responsive allocation
Another issue is the need for more flexible, responsive allocation. A number of Councils have, with limited success, explored systems for varying allocation on a seasonal basis in response to changes in the available resource, or intended changes in use and associated demand (e.g. for a change in seasonal crop types).
In the absence of a more flexible approach, councils are having to:
Acknowledgements and editorial comments
This guidance note was originally prepared by Ton Snelder, NIWA and Richard Keys, Marlborough District Council and was updated by Libby Manley, Ministry for the Environment.
This guidance note was prepared in August 2003 and updated in July 2006.
