<< 5-Waters Volume 2 - Water Supplies

<< Taumutu Water Supply

26 Te Pirita Water Supply

26.1 Scheme Summary

Description		Quantity
Estimated Population Served		28
Scheme Coverage (1 Jan 2021)	Full Charges	9
	Half Charges	0
	>1 Charges	1
System Components	Bores/Intakes (No.)	1
	Treatment/Disinfection	1
	Reservoirs (No.)	2
	Pump Stations (No.)	1
	Piped (m)	23,370.2
History	Original scheme installation date	Unknown
Value ($)	Replacement Cost	$1,952,998.88
Value ($)	Depreciated Replacement Cost	$1,094,175.62
Financial	Operator cost (scheduled and reactive maintenance) per connection	$2,448.47/connection
Demand (m3) (1 Jan – 31 Dec 2020)	Average daily	169.9
	Peak daily	365
	Minimum daily	7.3
	Average daily per connection	10.0
Type of Supply		Unrestricted metered tank supply
Target Pressure & Flow at boundary	Pressure	>150kPa
Target Pressure & Flow at boundary	Flow	±10% maric size
Sustainability	Well Security	Secure

26.2 Key Issues

The following key issues are associated with the Te Pirita water supply. A list of district wide issues are located in 5Waters Activity Management Plan: Volume 1.

Table 26‑1 Te Pirita Scheme Issues

What's the Problem	What we plan to do
The change in farming practice, especially from sheep and cattle to dairying has increased the demand for water. Dairy farming is more labour intensive and requires high quality water for cleaning of milking equipment.	Council will review the metering data and the associated impacts of demand. This will assist in identifying any capacity constraints that may exist. Metering will assist in ensuring that equitable payment for water use is made.
The Te Pirita scheme pipes were used for conveyance of river water prior to commissioning of the deep well in 1999. Repair reports in 2011 identified that they were not flushed prior to this change over. The silt has coagulated in the base of the pipes, and could affect water quality.	Initial flushing has occurred. Investigate options for silt removal. Proceed with silt removal and a methodology for maintenance of high quality water delivery including removal of silt is to be prepared by Council.
Catchment management	To encompass a holistic view of the drinking water supply improved liaison with ECan and study of groundwater quality within the water supply protection zones are being investigated.

26.3 Overview & History

The Te Pirita Water Supply provides untreated groundwater to a rural area of 2719ha. Water is obtained from a single deep well in the community. The bore has been demonstrated as a source of secure groundwater. All connections within this scheme for domestic and stock use currently have a double check valves (backflow prevention device).

The area was originally served by the Snowden Water Race System (operated by the then Malvern County Council). Due to the inability of the water race scheme to give a reliable supply the Ellesmere County Council installed a piped supply to serve the Ellesmere area served by the then Snowden supply.

The scheme was designed as a restricted supply for stock use only. Restrictors were never installed and consequently the scheme operates as an on demand scheme directly into tanks and stock troughs, except for Robindale Lodge which is supplied directly.

Initially the water was chlorinated at the pump station. This was never satisfactory as water quality varied significantly (supplied from Ellesmere Stock Water Race).

In 1998 the scheme intake was replaced by a deep well and associated variable speed submersible pump.

Installation of water meters on each individual connection occurred in 2005/06, and per cubic metre charging was initiated.

A single bore pump delivers water to 5 x 30m3 tanks, from which two pumps provide water to consumers’ tanks (no restrictors).

Figure 26-1
TE PIRITA Water - Scheme map
Open larger map: 'Water Scheme'

Figure 26‑2 Scheme Schematic

26.4 System Capacity

This rural water supply was developed to serve 10 rural properties, supplying water for domestic and agricultural use. All connections have been allocated and are utilised. No additional connections are allowed for. Demand has increased over recent years reflecting changing land use and additional farm dwellings, and will need to be managed within the constraints of the supply/consent.

Table 26‑2 Capacity Summary

	Flow Rate (L/s)	Daily Volume (m³)	Annual Volume (m³)	Comments
Abstraction Capacity	6	-	-	Limited by submersible bore pump capacity
Consented Take	10	450	67,500	-
Treatment capacity	9.3	-	-	Max flow at 90% UVT
Peak Demand	-	365*	67,936**	Unrestricted tank supply

* 2020 ** 2014

26.5 Resource Consents

Table 26‑3 shows the water take permitted by the resource consent for this scheme.

Table 26‑3 Resource Consents

Consent	Description	Location	Date Issued	Expiry Date	Consented Max Instantaneous Flow (L/s)	Consented Max Daily Volume (m³/day)
CRC991530.1	To take groundwater via bore L36/1313, at or about map reference NZMS 260 L36:2075-2981 for public water supply.	cnr Te Pirita & Sharland Roads, HORORATA	12-Feb-10	9-Apr-34	10	450

26.6 Water Quality

The Te Pirita water supply is a secure source and is currently sampled quarterly at the treatment plant and reticulation zone.

The following details E. coli transgressions for the period 2012 to 2020.

Treatment

There has been no E. coli transgressions during this period.

Zone

There have been three E. coli transgressions during this period. These occurred in April 2015 and two occurred in May 2015.

Chemical Analysis

The following is a summary of the raw water chemical analysis carried out at the Te Pirita Water Supply.

Table 26‑4 Te Pirita Water Supply Raw Water Chemical Analysis Summary

Parameter	Standards	2008	2011	2013	2015	2017	2018	2019	2020	Status
Total Lead (g/m3)	0.01 (Maximum Acceptable Value)	<0.0001	<0.00011	<0.00011	0.00041	0.00019	<0.00011	<0.00011	0.000388	✓
pH (pH units)	7-8.5 (Guideline Value)	7.5	7.4	7.6	7.8	7.7	7.7	7.7	7.8	✓
Total Hardness (g/m3 as CaCO₃)	<200 (Guideline Value)	49	56	52	54	47.0	54.5	57.4	57.2	✓
Total Calcium (g/m3)	n/v	16	19	17.5	18.1	16.0	18.3	19.31	19.36	✓
Total Iron (g/m3)	<0.2 (Guideline Value)	<0.02	<0.021	<0.021	0.083	<0.021	<0.021	<0.021	<0.021	✓
Total Sodium (g/m3)	<200 (Guideline Value)	4.4	4.8	5.0	4.9	4.4	5.0	4.99	5.05	✓
Nitrate - Nitrogen (g/m3)	11.3 (Maximum Acceptable Value)	2.1	3.2	3.1	3.8	2.3	3.99	4.13	4.33	✓

26.7 Scheme Assets

A summary of material and diameter for pipes in Te Pirita is shown below in Figure 26‑3 and Figure 26‑4.

Figure 26‑3 Pipe Material – Te Pirita

Figure 26‑4 Pipe Diameter – Te Pirita

26.8 Operational Management

The water supply is operated and maintained under two maintenance contracts as follows:

Contract 1241: Water Services Contract. Contract is with SICON who undertakes investigations, conditions inspections, proactive and reactive maintenance and minor asset renewals; and
Contract 1202: Parks and Reserves Contract. Contract is with SICON who undertakes the maintenance of land scape features related to water services e.g. mowing, gardens etc.

Water quality sampling is completed under an agreement with Food and Health Ltd as required.

26.9 Photos of Main Assets

Photo 1: Wellhead, Tanks and Pump Shed
Photo 2: Te Pirita Water Treatment Plant

26.10 Risk Assessment

A risk assessment has been undertaken for the Te Pirita scheme. 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 this LTP. Table 26‑5 details the risk priority rating, Table 25‑6 outlines the risks and the list of key projects is found in Table 26‑11.

Table 26‑5 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 26‑6 Risks – Te Pirita

Risk	Action/Project	Year Identified	2014 Risk Rating	2017 Risk Rating	Residual Risk Rating
Electrical failure due to lightning or network spikes	Install surge diverters	2014	6	6	6
Failure to meet NES water meter standards	NES Water Meter Compliance	2014	20	6	6
Inability to collect income from non-metered properties	Install property water meters	2014	27	0.6	0.6
Non-compliance with the DWSNZ	DWSNZ - Age Testing	2014	6	0.7	0.7
Non-compliance with the DWSNZ	DWSNZ - Bore-head security	2014	6	6	6
Non-consented activities	Renewal of consents	2014	27	27	6
Inadequate treatment under all conditions	UV treatment	2017		1	1

The list of district wide risks can be found in 5Waters Activity Management Plan: Volume 1.

26.11 Asset Valuation Details

The total replacement value of assets within the Te Pirita water scheme is $2,093,313 with further details in Table 26‑7 below.

Table 26‑7 Replacement Value, Te Pirita

Asset Class 1	Asset Class 2	Sum of Replacement Value
Plant and Equipment		$290,842
Water Reticulation	Hydrant	$2,310
	Lateral	$3,723
	Pipe	$1,774,292
	Supply Point	$19,850
	Valve	$2,296

26.12 Renewals

The renewal profile has been taken from the 2019 5 Waters Valuation. A graph showing the renewals for this scheme is shown by Figure 26‑5 below. The majority of renewals occur in 2025.

Figure 26‑5 Te Pirita Water Renewal Profile

26.13 Critical Assets

The criticality model for Te Pirita has been updated for the 2021 AcMP. The methodology of the criticality model can be found in 5Waters Activity Management Plan: Volume 1 and it provides details of how the criticality has been calculated for the reticulation assets. Table 26‑8 and Figure 26‑6 below shows the calculated criticality for all of the assets within this scheme that have a recorded known length.

Table 26‑8 Length of Assets per Criticality Level

Criticality Bands		Length (m)
5	Low	12,240
4	Medium-Low	10,579
3	Medium	0
2	Medium-High	0
1	High	0

Figure 26-6
TE PIRITA Water - Criticality map
Open larger map: 'Water Criticality'

26.14 Asset Condition

The asset condition model was run for Te Pirita in 2021. The methodology of the model can be found in 5Waters Activity Management Plan: Volume 1 which provides details of how the model has been calculated for the pipe reticulation assets. Figure 26‑7 below shows the level of asset condition for these assets within this scheme that have a recorded known condition.

Figure 26-7
TE PIRITA Water - Condition map
Open larger map: 'Water Condition'

Table 26‑9 provides a description of the condition rating used within the condition model.

Table 26‑9 Asset Condition Grading

Condition Rating	Grading
1.0	Excellent
2.0	Good
3.0	Moderate
4.0	Poor
5.0+	Fail

The number of pipe faults is also measured through the asset management system. Figure 26‑8 shows the known historic pipe failures within this scheme.

Figure 26-8
TE PIRITA Water - Pipe Faults map
Open larger map: 'Water Pipe Faults'

26.15 Funding Program

The 10 year budgets are shown by Table 26-10. Budgets are split into expenditure, renewals, projects and capital projects. Expenditure and renewals have been reported on a district-wide basis in Volume 1.

All figures are ($) not adjusted for CPI “inflation". They are calculated on historical data, and population growth where relevant.

Table 26-10 Budget Summary

Years	Projects	Capital Projects
2021/2022	$15,000	$130,000
2022/2023	-	-
2023/2024	-	-
2024/2025	-	-
2025/2026	-	-
2026/2027	-	$400,000
2027/2028	-	-
2028/2029	-	-
2029/2030	-	-
2031/2032	-	-
Total	$15,000	$530,000

An explanation of the categories within the budgets are as follows below:

Expenditure consists of operation and maintenance costs;
Renewals are replacement of assets which are nearing or exceeded their useful life;
Projects are investigations, decisions and planning activities which exclude capital works; and
Capital projects are activities involving physical works.

Table 26-11 Key Projects

Account Label	GL	Description	Year 1($)	Year 2($)	Year 3($)	Years 4 to 10	Funding Split *
Capital Projects	-	Spare pump	$30,000	-	-	-	100% LoS
Capital Projects	-	Extra source and storage	-	-	-	$400,000	TBC
Capital Projects	-	Consent renewal	$100,000	-	-	-	100% LoS
Projects	-	Model connection to Hororata	$15,000	-	-	-	100% LoS

* Where LoS refers to Level of Service and G refers to Growth

The list of district wide projects can be found in 5Waters Activity Management Plan: Volume 1.

Discussion on Projects

Projects have been determined based on their:

Relevance to the scheme
Requirement to be completed under legislation
Ability to bring the scheme up to or maintain the Level of Service required under council's Asset Management Policy.

Many projects are jointly funded by more than one scheme and activity. Each scheme pays a pro-rata share only, equivalent to the number of connections.

Discussion on Capital and Projects

Where relevant, Capital (Levels of Service) and Capital (Growth) projects have been included in the scheme financial details.

Levels of Service Projects and growth splits have been provided to ensure the costs of population driven works are clear.