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3 Activity Areas

This section of the Plan details the rationale for ownership of the 5Waters assets and the description of assets covered under it.

Figure 3‑1 Selwyn District Overview

The Selwyn District Council is a local authority situated in the South Island of New Zealand. The Council was formed in 1989, as a result of an amalgamation.

The Council is a provider of “core" activities which are considered to be delivery of water (urban and rural), wastewater, stormwater, land drainage and water races services. These are 5 of the 11 Council activities.

The Council is located in the heart of the Canterbury Region's groundwater zone. How and where water for human, agricultural, cultural and recreational uses is managed is of considerable interest to Canterbury residents. Council has consistently regarded the provision of the 5Waters as vital to maintaining the community's health and well-being.

The Council provides services to residents via 81 5Waters Schemes. The 5Waters are summarised in Table 3‑1 below.

Table 3‑1 Summary of the 5Waters Services*

Services	Schemes	Serviced Properties (no.)	Operating Costs (Total of 2021-31)	Replacement Value as at 1 July 2019
Water	27	19,242	$50,645,602	$184,226,000
Wastewater	14	15,330	$53,733,107	$311,469,000
Stormwater	22	15,818	$12,661,523	$70,207,000
Land Drainage	10	7,314	$2,508,093	$45,098,000
Water Races	3	14,609	$24,232,460	$117,674,000
Total	76	72,313	$143,780,785	$728,674,000

* Septage pit sites are not included in this summary

Council has access to a globally unique, high quality water source. Secure and uncontaminated freshwater for drinking is still delivered to the majority of accessible populated areas in the district. How Council ensures that this life-giving resource is preserved for future generations is of utmost importance.

Generally streams, rivers and springs are not part of this activity, as they are managed by the overarching authority – the Canterbury Regional Council. In fact, the Canterbury Regional Council has delegated authority to manage the water resource, with Council one of approximately 18,0000 parties requesting consent to take/use and discharge it.

3.1 Water

The following section describes the potable (drinking) water activity. Further detail on this activity is provided in Volume 2: Water Supplies.

3.1.1 Water Supply Principles

There are six principles of water management, these were identified in the Havelock North Inquiry in 2017. These principles are ingrained in good practice worldwide and should imbue every aspect of the New Zealand approach to drinking water. These six principles are outlined in this section.

Principle 1: A high standard of care must be embraced

Unsafe drinking water can cause illness, injury or death on a large-scale. All those involved in supplying drinking water (from operators to politically elected representatives) must therefore embrace a high standard of care akin to that applied in the fields of medicine and aviation where the consequences of a failure are similarly detrimental to public health and safety. Vigilance, diligence and competence are minimum requirements and complacency has no place.

Principle 2: Protection of source water is of paramount importance

Protection of the source of drinking water provides the first, and most significant, barrier against drinking water contamination and illness. It is of paramount importance that risks to sources of drinking water are understood, managed and addressed appropriately. However, as pathogenic microorganisms are found everywhere, complete protection is impossible and further barriers against contamination are vital.

Principle 3: Maintain multiple barriers against contamination

Any drinking water system must have, and continuously maintain, robust multiple barriers against contamination appropriate to the level of potential contamination. This is because no single barrier is effective against all sources of contamination and any barrier can fail at any time. Barriers with appropriate capabilities are needed at each of the following levels: source protection; effective treatment; secure distribution; effective monitoring; and effective responses to adverse signals. A “source to tap" approach is required.

Principle 4: Change precedes contamination

Contamination is almost always preceded by some kind of change and change must never be ignored. Sudden or extreme changes in water quality, flow or environmental conditions (for example, heavy rainfall, flooding, earthquakes) should arouse particular suspicion that drinking water might become contaminated. Change of any kind (for example, personnel, governance, equipment) should be monitored and responded to with due diligence.

Principle 5: Suppliers must own the safety of drinking water

Drinking water suppliers must maintain a personal sense of responsibility and dedication to providing consumers with safe water. Knowledgeable, experienced, committed and responsive personnel provide the best assurance of safe drinking water. The personnel, and drinking water supply system, must be able to respond quickly and effectively to adverse monitoring signals. This requires commitment from the highest level of the organisation and accountability by all those with responsibility for drinking water.

Principle 6: Apply a preventive risk management approach

A preventive risk management approach provides the best protection against waterborne illness. Once contamination is detected, contaminated water may already have been consumed and illness may already have occurred. Accordingly, the focus must always be on preventing contamination. This requires systematic assessment of risks throughout a drinking water supply from source to tap; identification of ways these risks can be managed; and control measures implemented to ensure that management is occurring properly. Adequate monitoring of the performance of each barrier is essential. Each supplier's risk management approach should be recorded in a living WSP which is utilised on a day to day basis.

3.1.2 Description of the Activity

Council manages 27 water supplies, located between the main divide and Pacific coast (Figure 3‑2). They supply water for public needs including household, gardens, and public reserves. The water supplies service 80% of residential properties within the district.

Figure 3‑2 Location of Selwyn Water Schemes

The diverse geographic supply location brings with it the need to provide water that meets the particular communities needs. For example:

Arthurs Pass is frost prone and has a high tourist and bach population. Water for outdoor needs is not required; whereas
Rolleston has a dense urban population, with large recreation reserves and highly permeable soils. Water use is high in summer, driven by long periods of north-west wind conditions.

A summary of the 28 water supplies is provided below in Table 3‑2.

Table 3‑2 Summary of Water Schemes

Scheme	Full Charges as at 1 Jan 2021	Replacement Cost as at 2019	Operator cost ($/connection)	Average Daily Demand (m3)
Acheron Water Supply	21 (+218 restricted)	$6,997,173	$563	623
Arthur's Pass Water Supply	120 (+3 restricted)	$872,883	$560	67
Castle Hill Water Supply	131	$2,696,878	$291	140
Claremont Water Supply	54 (+5 restricted)	$687,006	$701	153
Dalethorpe Water Supply	101 connections (405 units)	$4,711,133	$351	389
Darfield Water Supply	1,026 (+302 restricted)	$22,277,513	$111	1,893
Dunsandel Water Supply	172 (+4 restricted)	$1,906,696	$319	336
Hartleys Road Water Supply	120 (+3 restricted)	$10,867,661	$351	1,029
Jowers Road Water Supply	18	$189,054	$1,475	32.9
Kirwee Water Supply	357 (+101 restricted)	$5,920,750	$156	606
Lake Coleridge Water Supply	58 (+1 restricted)	$1,077,802	$1,033	26
Leeston/Doyleston Water Supply	1,033 (+19 restricted)	$6,553,418	$125	948
Lincoln Water Supply	2,544 (+28 restricted)	$13,555,301	$67	2,484
Prebbleton Water Supply	1,555 (+39 restricted)	$10,218,050	$108	1,993
Rakaia Huts Water Supply	113	$563,424	$370	107
Raven Drive Water Supply	12	$347,971	$2,388	17
Rolleston Water Supply	6,541 (+6 restricted)	$50,877,472	$78	8,684
Hororata Water Supply	59 (+47 restricted)	$11,722,760	$563	1,217
Sheffield/Waddington Water Supply	157 (+46 restricted)	$4,384,297	$371	310
Southbridge Water Supply	346 (+8 restricted)	$2,589,558	$201	345
Springfield Water Supply	176 (+31 restricted)	$4,139,463	$496	458
Springston Water Supply	189	$1,229,603	$325	162
Tai Tapu/Otahuna Water Supply	212 (+58 restricted)	$3,006,685	$376	404
Taumutu Water Supply	16 connections	$131,279	$1,357	12
Te Pirita Water Supply	9	$1,952,998	$2,448	170
Upper Selwyn Huts Water Supply	97 connections	$166,452	$237	29
Greater West Melton Water Supply	856 (+8 restrictied)	$9,909,651	$265	1,283

3.1.3 Key Issues

The following key issues have been identified across the Councils water schemes. Issues within each individual scheme is provided in Volume 2 of the AcMP. And issues common to one or more of the schemes are cited below in Table 3‑3.

Table 3‑3 District Wide Key Issues

Common Issues	Description
Water Management	The regional focus on wise use of water is being reflected in demand management based consent conditions.
Water quality upgrades and the associated capital burden on applicable communities	This is driven by WSPs and the underlying Drinking Water Standards 2005 (revised 2018).
The need for more source water in growth areas, especially Eastern Community in urban areas.	The District continues to experience strong growth, which results in increasing water demand.
Operations and Maintenance costs of assets	Driven by increasing costs of contractors, compliance requirements and addition of new assets to service growth.
Long travel times	Are a significant issue for Council in the remote schemes
Continued focus on criticality and improving asset knowledge	Asset management requires complete data. Including a need to maintain condition assessments and calculate advanced renewal profiles.

3.1.4 Operations and Maintenance

Council has three full-time water supply operations staff (a drinking water quality scientist, a water engineer and a contract supervisor), who run the water supply schemes within the district. These staff members are supported by projects engineers, a SCADA engineer and two admin staff who work across the other 5Waters schemes.

Under contract C1241 Water Services Network Management Contract scheduled and reactive maintenance work is undertaken by SICON for Council water supplies. This contract was approved by Council on the 22^th June 2016 for a period of 1 July 2016 to 30 June 2021. Contract negotiations are underway for the renewal of the contract. The new contract rates have been integrated into budgets.

3.1.5 Demand and Capacity

High growth in the eastern urban townships including Rolleston, Lincoln, West Melton, Leeston and Prebbleton is driving the need for more public drinking water from these townships sources – both at existing and new sites.

3.1.5.1 Current Demands

As schemes vary in size from less than 10 connections to over 7,000 connections, the individual water scheme needs also differ. However when looking at a per person demand (litres per person per day) is it clear that the smaller schemes use more water than the larger ones. This is shown by Figure 3‑3 below for 1^st January to 31^st December 2014, note that the rural schemes have been excluded as this skews the graph. The rural schemes are Malvern Hills, Hororata Acheron and Te Pirita which used 3.84, 23.85 and 16.97 m³ per connection per day respectively.

Figure 3‑3 Average Water Use per Scheme

3.1.65.2 Future Demand

Future demand considerations must be take into consideration:

Existing resource consents and their flow rate limitations;
Existing pumping capacity;
Existing peak flow and future flow requirements; and
Increase or decrease in population/number of dwellings.

Council have a key performance indicator targeting the average consumption of drinking water per resident per day. This has been set at 0.5 m³per person per day within urban schemes for 2021/22. with a falling target in subsequent years. While not formally adopted by Council this is considered a reasonable first step in working towards the wise use of water.

3.1.6 Water Resource Consents Summary

This section identifies the type and scale of public water supplies in the district.

The majority (68%) of public water is sourced from the Waimakariri zone. This provides 85% of the daily consented water volume (volumes have been annualised where necessary). This is shown below in Figure 3‑4 and Figure 3‑5.

Figure 3‑4 Water Consents by Water Source

V1 Figure 3-5.png

Figure 3‑5 Water Consent Volume by Water Source

The majority of consented annual volume is for Rolleston, Prebbleton and Darfield (this does not include consents which only have a litres per second take). This shown in Figure 3‑6 below.

V1 Figure 3-6.png

Figure 3‑6 Consented Daily Volume by Scheme

3.1.7 Water Quality

There are 9 river/gallery intakes, 1 lake intake and 49 deeper groundwater takes. The river/gallery and lake sources provide unsecure water with bacteria and silt from time to time. Water Safety Plans (WSPs) aim to address these relatively poor water quality schemes.

The WSPs are scheduled for review every five years. The completion of WSPs does not necessarily mean there will be a change in water grades. Instead acceptance of risk through the WSP is an acknowledgement by the community and Council that they will carry some risks and deal with others through financial and Council resources. In effect the WSP prioritises work by the level of risk it poses to human health.

Source, treatment plant and reticulation water is regularly tested for the presence of bacteria. Results for the period 2012-2020 are provided in Figure 3‑7, Figure 3‑8 and Figure 3‑9. These results are a reflection that the water supply communities generally have access to high quality water.

Figure 3‑7 Source Sampling and Bacteria Transgressions

Figure 3‑8 Treatment Plant Sampling and Transgressions

Figure 3‑9 Reticulation (Zone) Sampling and Transgressions

Turbidity is also sampled for the water schemes. Turbidity has a 'guidance value for aesthetic determinants' set at 2.5NTU.

3.1.8 Bore Pumps

The water supplies located on the Selwyn plains area rely on pumped systems to take deep groundwater either direct into the network and/or to surface reservoirs. Pumping capacity is limited by the rate (litres per second) specific to each scheme's resource consent.

Council has a focus on making the most efficient match of pumps and pumping systems to the water demand of each community. Variable speed drive systems are used extensively to:

Reduce the pump start up energy load on the mainline network; and
Minimise the energy used to meet customer water needs.

In more alpine areas, such as Arthurs Pass, gravity conveyance of water from the steep surrounding catchments is used to provide water to customers.

3.1.9 Water Treatment

23 of 27 schemes are located in the plains area, where deep generally secure groundwater can be obtained.

In the shallow unsecure water schemes, Council uses filtration, ultra violet light (UV) and chlorination treatment systems to reduce the likelihood of source water organisms entering the community water network.

Details of treatment are provided in Volume 2 at a scheme level however, a summary is provided below. This summary identifies which sources have permanent barriers installed to make water safe to drink i.e. in their normal operation. During transgression events, chlorination may be used in addition to existing treatment where applicable. Refer table Table 3‑4 below for a summary of treatment systems for each water supply.

3.1.10 Water Quality and Chlorination

Selwyn District Council is committed to providing our communities with safe drinking water.

The Council currently uses a variety of water treatment methods for its 27 water supplies and all supplies have Water Safety Plans which are approved by the Canterbury District Health Board. Treatment methods used in various supplies include secure ground water (to meet current New Zealand Drinking Water Standards), Ultraviolet (UV) disinfection, selective abstraction, filtration, and chlorination. For more information on the ways that we treat water, visit: https://www.selwyn.govt.nz/services/water/water-supplies/water-quality-in-selwyn-district

Below are some answers to common questions about chlorination.

Why would SDC want to add chlorine to our water?

We want to make sure that everyone in the Selwyn District has safe drinking water. The Health Act makes SDC responsible for providing a safe and wholesome drinking water supply and to do everything practicable to meet the NZ Drinking Water Standards.

On the 20 December 2017 The Director-General of Health issued a formal statement reminding water suppliers of their statutory responsibilities set out in the Health Act 1956.

The formal statement recommends reconsidering reliance on 'secure bores' and warns that the public risk is increased if drinking-water is untreated. Councils and DHBs have been advised to seek information from public health units on the need to disinfect any drinking-water supply that is currently not being treated. The Ministry strongly advises water should be treated, with chlorination the safest treatment option.

We already have UV treatment so why do we need chlorine too?

UV (ultra violet light) treats the water where it enters our supply network. It is very effective as long as the water is not turbid (discoloured). UV treatment does not treat the water once it is in our reservoirs and pipes.

There is always the potential for contaminants to get into the water reticulation system, for example through cracks in the reservoir, broken pipes – tree roots growing through pipes are a potential problem, as are unlawful connections from households where people do their own plumbing. A chlorine residual provides protection against this type of contamination.

How much chlorine will you use?

As little as possible to keep your water safe. Typically we will use a dose of 1.0 - 0.5mg of chlorine for every litre of water. This will give a residual dose of 0.3mg per litre in what comes through your taps.

I've heard that chlorine is unsafe – is that true?

Chlorine has been used safely all over the world for around 120 years. It keeps millions of people all round the world – including most of New Zealand – safe from waterborne illness.

The amount of chlorine dosed into the water supply will be carefully managed to ensure levels of chlorine in the water people drink are absolutely minimised.

In a small number of people chlorine can be an irritant for an existing condition such as asthma or eczema. If you feel your skin getting dry or itchy use moisturiser after having a shower or bath. If you notice increased skin irritation, asthma symptoms or other symptoms – seek medical advice from your GP.

The use of filters will mitigate any risks for those on dialysis. This can be arranged by the Canterbury District Health Board.

I don't like the taste of chlorinated water. Is there anything I can do?

If you are concerned about the taste, you can either:

Fill a jug of water and leave it on the bench or in your fridge overnight. The chlorine will dissipate naturally over a few hours. or
Install an under-bench filter. Chlorine and any associated by-products can removed by using a granulated, activated carbon (GAC) filter. These are available from hardware supplies stores and water filter companies.

I don't want to shower or wash my clothes in chlorinated water – what can I do?
You can buy a carbon filter that attaches to your water supply where it enters your property. It will remove all the chlorine from the water to your home.

Pets
If you have fish in outside ponds you will need to either turn down in-coming water to an absolute trickle (this dilutes the chlorine level to a safe amount for your fish), or fill up drums of water and let them sit for at least 24 hours before using (the UV of the sun evaporates chlorine).
For fish tanks or bowls inside, fill up a container of water and let it sit for at least 24 hours and then only replace 1/3 of this water at a time with what is in the tank already. If you're still worried, you can buy de-chlorinating kits (sodium thiosulfate) at pet supplies stores.

What are the Drinking Water Standards?

The Drinking Water Standards for New Zealand are issued by the Ministry of Health(external link) under the Health Act and set out the requirements water suppliers need to meet to provide safe water to their communities. The standards specify:

Maximum amounts of substances, organisms, contaminants and residues that may be present in drinking water.
Criteria for demonstrating compliance with standards.

Remedial action to be taken in the event of non-compliance with standards.
V1 Table 3-4.png

Table 3‑4 Public Water Supply Treatment Devices (normal operation)

3.1.11 Reservoirs

Council has above and below ground water storage. Above ground storage reservoirs are timber, concrete and plastic material and are reasonably durable. Below ground aquifer systems are considered to be a secure and appropriate type of storage, though with increasing catchment abstraction, monitoring of recharge and well levels is required.

V1 Figure 3-Reservoir.jpg

The philosophy that below ground storage via the aquifer is appropriate comes with the:

Risk that the aquifer yields not remain constant; and
Requirement that adequate and resilient redundancy in surface pumping and electrical systems is available; and
Above ground storage is provided in steel reinforced concrete and wire band timber tanks.

Above ground storage is employed to:

Ensure sufficient water is available over peak demand periods. A normal peak demand period is 2-5 hour, over which time the reservoir water is rapidly drawn down. Councils target storage for new schemes is 8 hours at peak demand. Existing schemes are configured to utilise ground and surface storage, pipe capacity and reservoirs; and
Allow for lower rates of water source take, and stop oversizing of mainline pipes and pumping systems ; and
Provide fire flow requirements, where a set volume of water is reserved for fire flow needs.

A review of all Councils public water supply reservoirs was undertaken after the September 2010 Greendale earthquake. This review identified there was no severe damage which required urgent attention, but repairs were needed. These repairs have either been completed or are planned.

3.1.11 Water Storage for Fire Fighting

New Zealand Fire Service Firefighting Waters Supplies Code of Practice “The Code" is a publicly available specification published by Standards New Zealand (SNZ PAS 4509:2008). It provides criteria around what constitutes a sufficient minimum supply of water pressure and volume for firefighting in structures in Urban Fire Districts. A Code such as this is non-mandatory but can be incorporated into relevant bylaws or district plans. Council have not incorporated it into the 2008 Water Supply Bylaws. The Code is not necessarily relevant to water supplies in rural areas. However, Council may wish to use some aspects of the Code as a guide. The Code includes guidance on provision of alternative firefighting water sources that may be appropriate to rural firefighting needs.

Council works with FENZ to determine firefighting water requirements throughout the district. The table below provides an indication of the firefighting water requirements for each urban area in Selwyn District.

Darfield

Dunsandel

Kirwee

Leeston

Doyleston

Lincoln

Prebbleton

Rolleston

Sheffield/Waddington

Southbridge

Springfield

Springston

Tai Tapu

West Melton

There are urban areas, most of which have local volunteer fire brigades. It would be appropriate for Council to provide a fire fighting water supply in general accordance with the Code.

It should be possible to meet FW2 Code requirements for the urban areas served by Council water supplies. It may be possible to provide a higher standard for business zones in the larger towns. Izone should be targeted for provision of a higher level of fire fighting water supply.

Arthur's Pass

Castle Hill

Lake Coleridge

Rakaia Huts

Arthur's Pass and Lake Coleridge have Volunteer Rural Fire Forces (VRFF). These towns are served by mains pressure water supplies.

Where practicable, Council should seek to meet FW2 Code requirements for the Living Zone areas served by the community water supply. Hydrants should be provided within the prescribed distances of structures even if flows and volumes cannot be provided or sustained for the desired period.

Armack Drive

Branthwaite Drive

Edendale

Taumutu

Templeton (Claremont)

Upper Selwyn Huts

These small rural communities are typically rural-residential subdivisions served by very small mains pressure water supplies that will not be able to provide adequate flows for fire fighting.

The provision of hydrants, tanker filling points and identification of alternative water sources are options to facilitate fire fighting, even if only in a limited way. Private on-site storage, or community storage may be appropriate.

Burnham

Jowers Road

Johnson Road

Raven Drive

These small rural communities are typically rural-residential subdivisions served by low-pressure water schemes supplying tanks on each property.

Whitecliffs, Glentunnel, Coalgate (MHRWS)

Hororata (Selwyn RWS)

Hororata and Coalgate have auxiliary volunteer rural fire brigades. These towns are supplied from rural water schemes supplying tanks on each property.

Darfield (rural)

Kirwee (rural)

Leeston (rural)

Malvern Hills RWS

(excl towns)

Selwyn RWS (excl. towns)

Sheffield/Waddington (rural)

Springfield (rural)

Tai Tapu (Otahuna)

Te Pirita RWS

These small communities and rural areas have rural water schemes providing low pressure water to tanks on each property. Some are an extension of the local town supply.

3.1.12 Risk Assessment

A risk assessment has been undertaken for Water Supplies. The key output from the risk assessment is the identification of any extreme and high risks which need to be mitigated. In order to mitigate these risks they have been included and budgeted for in the projects within the LTP. The list of business wide risks is in Section 9.2 and scheme wide risks are listed in 5Waters Activity Management Plan: Volume 2. Table 3‑7 below outlines the risk priority rating and Table 3‑8 lists the scheme wide risks.

Table 3‑7 Risk Priority Rating

Risk Score	Level of Risk	Risk Response
> 50	Extreme	Awareness of the event to be reported to Council. Urgent action to eliminate / mitigate / manage the risk. Document risk and action in the AMP.
35-50	Very High	Risk to be eliminated / mitigated / managed through normal business planning processes with responsibility assigned.
14-35	High	Manage risk using routine procedures.
3.5-14	Moderate	Monitor the risk.
< 3.5	Low	Awareness of the event to be reported to Council. Immediate action required to eliminate / mitigate / manage the risk. Document risk and action in the AMP.

Table 3‑8 Risks – Water Supplies

Risk	Action/Project	Year Identified	2014 Risk Rating	2017 Risk Rating	Residual Risk Rating
Inaccurate asset data causes inaccuracies in valuations and renewals programs	Carry out P&E inventory checks on assets	2014	20	20	20
Increasing number of easements	Document easements	2014	12	12	12
Lack of bore and reservoir turnover	Review bore and reservoir turn over	2014	27	27	12
backflow contamination	Staff project for inspections	2017		40	20
SCADA upgrade	Network SCADA Upgrade			20	10
Water quality does not meet DWSNZ	Review treatment and upgrade as required	2017		40	7

3.1.13 Funding Program

Section 11.0 provides the financial summary and details the funding and expenditure across the 5Waters activities. An overall summary of the funding program for the water supply activity is outlined within this section.

The 10 Year financial programme for the 5Waters is divided into the following categories:

Expenditure – Operations and Maintenance;
Projects – either specific or jointly funded;
Capital Projects - result in new assets; and
Renewals - replacement of assets on a like for like basis within a 20 year horizon.

Table 3‑9 and Figure 3‑10 outline the budget for the water supply activity for the next 10 years.

Table 3‑9 Water Supply Budget Summary

Values	Expenditure	Renewals	Projects	Capital Projects
Year 1	$4,586,606	$3,742,709	$558,500	$10,875,806
Year 2	$4,730,201	$3,742,709	$575,561	$10,005,122
Year 3	$4,826,952	$3,742,709	$307,000	$5,981,358
Years 4 to 10	$36,501,843	$24,233,963	$1,364,000	$17,533,653
Total	$50,645,602	$35,462,090	$2,805,061	$44,395,939

Figure 3‑10 Water Supply Financial Summary

3.1.13.1 Shared Projects

There are a number of shared projects for water. Shared projects are projects across one activity which share the costs across all schemes as they all receive the benefit.

The list of scheme specific projects can be found in Volume 2: Water Supplies.

Table 3‑10 Key Shared Projects

Project Type	GL	Description	Year 1 ($)	Year 2 ($)	Year 3 ($)	Years 4 to 10	Funding Split *
Capital Projects	400090036	Backflow	$19,920	$50,000	$50,000	$800,000	100% LoS
Capital Projects	-	Reservoir upgrades	-	-	-	$200,000	100% LoS
Capital Projects	400090039	Water metering	$200,000	-	-	-	100% LoS
Capital Projects	-	Implement findings of pressure plan	-	-	$200,000	-	100% LoS
Capital Projects	-	Security upgrades at all sites	-	$100,000	-	-	100% LoS
Projects	-	Groundwater quality monitoring to give early warnings of water quality issues	$30,000	$10,000	$10,000	$70,000	100% LoS
Capital Projects	-	Chlorination	$1,000,000	-	-	-	100% LoS
Capital Projects	-	Review bulk water extraction process and implement findings	-	-	-	$300,000	100% LoS

* LoS refers to Level of Service; G refers to Growth

3.2 Wastewater

This section describes the wastewater activity. Further detail on the schemes is provided in Volume 3: Wastewater.

3.2.1 Description of the Activity

The Council is responsible for 14 reticulated wastewater systems that service 63% of properties within the district, shown in Figure 3‑11. Reticulated community wastewater schemes have been provided where:

Unsanitary conditions were created through high groundwater conditions and/or urban growth; and
Sale of Crown operations to Council required that a reticulated scheme be provided for, e.g. Arthurs Pass and Lake Coleridge.

The wastewater schemes have a replacement value of approximately $311M (excluding land value). Overall there are 54 pump stations and 8 wastewater treatment and disposal plants. The total length of the reticulation is 574 km, varying in diameter from DN50 to DN600.

Figure 3‑11 Location of Wastewater Systems

Council also used to operate 2 septage pits – Ardlui Road and Bleakhouse Road. These take septic tank (household and small business) wastewater. Council is investigating wastewater management options for Darfield and Kirwee, which currently rely on individual onsite treatment and disposal systems. These schemes are discussed in Volume 3: Wastewater at a scheme level. Wastewater effluent discharge quality must be within Councils Wastewater Bylaw 2008 criteria. Outside these standards, the discharger is covered by Tradewaste Bylaw criteria.

A summary of the wastewater schemes is provided below in Table 3‑11.

Table 3‑11 Summary of Wastewater Schemes

Scheme	Full Charges as at 1 Jan 2021	Replacement Cost as at 1 July 2019	Operator cost ($/connection)
Arthur's Pass Wastewater Scheme	9	$304,471	$6,024
Castle Hill Wastewater Scheme	134	$4,998,794	$76
Claremont Wastewater Scheme	49	$2,566,534	$1,003
Doyleston Wastewater Scheme	113	$2,025,568	$381
Eastern Selwyn Sewer Scheme	-	$66,919,041	$119
Ellesmere Sewer Scheme	-	$4,309,666 (P&E only)	$258
Lake Coleridge Wastewater Scheme	51	$1,573,791	$1,297
Leeston Wastewater Scheme	874	$15,310,917 (excluding P&E)	$101
Lincoln Wastewater Scheme	2,520	$56,108,676	$81
Prebbleton Wastewater Scheme	1,502	$28,780,428	$105
Rolleston Wastewater Scheme	6,338	$88,879,203	$46
Septage Disposal Facilities	-	-	-
Southbridge Wastewater Scheme	327	$9,412,187	$166
Springston Wastewater Scheme	177	$5,013,825	$145
Tai Tapu Wastewater Scheme	210	$6,006,183	$136
Upper Selwyn Huts Wastewater Scheme	97	$942,462	$243
West Melton Wastewater Scheme	692	$10,661,568	$76

3.2.2 Key Issues

The following key issues have been identified across the Councils wastewater schemes. Issues within each individual scheme is provided in Volume 3 of the AcMP. Issues common to one or more of the schemes are below in Table 3‑12.

Table 3‑12 District Wide Key Issues

Common Issues	Description
High Infiltration and Inflow rates	Leeston, Lincoln, Springston, Upper Selwyn Huts
Te Waihora Water Conservation Order (2011) strengthened protection of cultural values and the Land and Water Plan requirements	Upper Selwyn Huts treatment and disposal system is installed on the lake edge with consent due to expire.
Renewals	Costs for asset replacement in high groundwater areas have increased Upper Selwyn Huts reticulation are Grade 5 (very poor) condition
Capital Works - ESSS	Financing Pines Extension
Darfield-Kirwee	High growth is predicted for Darfield. A wastewater system is programmed for year13 of the LTP.
Septage Sites – Ardlui and Bleakhouse	Sites now closed and require remediation.
Long travel times	Are a significant issue for Council in the remote schemes

3.2.3 Operations and Maintenance

Council has two full time wastewater operations staff (an engineer and a contract supervisor), who run the wastewater schemes within the district. These staff members are supported by projects engineers, a SCADA engineer, and two admin staff who work across the other 5Waters schemes.

Under contract C1241 Water Services Network Management Contract scheduled and reactive maintenance work is undertaken on these supplies. This contract was approved by Council on the 22^th June 2016 for a period of 1 July 2016 to 30 June 2021. Contract negotiations are underway for the extension of the contract. The new contract rates have been integrated into the budgets. Telemetry is heavily relied upon to provide early warning of scheme faults.

3.2.4 Demand and Capacity

High growth in the eastern urban townships including Rolleston, Lincoln, West Melton and Prebbleton is driving the need for upgrades and expansion of the existing treatment plants

3.2.5 Treatment Plants Summary

An overview of the eight wastewater treatment plants is provided below in Table 3‑13 below with a brief outline of the treatment plants further below. Specific scheme details are provided in Volume 3: Wastewater.

Table 3‑13 Selwyn Sewer Treatment Plants

Wastewater Scheme	Currently connected to
Arthurs Pass	Community Treatment Plant
Castle Hill	Community Treatment Plant
Claremont	Community Treatment Plant
Doyleston	Leeston - pumped to Leeston, treated and disposed of via “Ellesmere" WWTP
Lake Coleridge	Community Treatment Plant
Leeston	Ellesmere Community Treatment Plant Multi staged maturation ponds followed by border-dyked irrigation. When groundwater is high, discharge is to drains via ground filtration basins. Consents expire 2029. In the 2021-31 LTP, Council have consulted on the proposal to pipe wastewater from Ellesmere WWTP to Pines WWTP.
Lincoln	Eastern Selwyn Sewer Scheme – pumped to Rolleston, treated and disposed of via “Pines" WWTP
Prebbleton	Eastern Selwyn Sewer Scheme – pumped to Rolleston, treated and disposed of via “Pines" WWTP
Rolleston	Eastern Selwyn Sewer Scheme – pumped to Rolleston, treated and disposed of via “Pines" WWTP
Southbridge	Leeston - pumped to Leeston, treated and disposed of via “Ellesmere" WWTP
Springston	Eastern Selwyn Sewer Scheme – pumped to Rolleston, treated and disposed of via “Pines" WWTP
Tai Tapu	CCC- pumped to Christchurch City, disposal at Bromley/Ocean Outfall
Upper Selwyn Huts	Community Treatment Plant In the 2021-31 LTP, Council have consulted on a proposal to pipe wastewater from Upper Selwyn Huts to Pines WWTP.
West Melton	Eastern Selwyn Sewer Scheme – pumped to Rolleston, treated and disposed of via “Pines" WWTP

3.2.5.1 Eastern Selwyn Sewer Scheme

The Eastern Selwyn Sewer Scheme serves the townships of Rolleston, Lincoln, Prebbleton, Springston and West Melton. Burnham Military Camp will connect in 2021. The purpose of this scheme is to ensure a staged and managed approach to the development of wastewater bulk conveyance, treatment and disposal infrastructure while providing equality in the scheme costs for existing residents, new developments and future generations.