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20 Sheffield / Waddington Water Supply

20.1 Scheme Summary

Description		Quantity
Estimated Population Served		592
Scheme Coverage (1 Jan 2021)	Full Charges	156
	Half Charges	0
	>1 Charges	48 (46 restricted)
System Components	Bores/Intakes (No.)	2
	Treatment/Disinfection	UV
	Reservoirs (No.)	1
	Pump Stations (No.)	0
	Piped (m)	40,607.95
History	Original scheme installation date	1990
Value ($)	Replacement Cost	$4,384,297
Value ($)	Depreciated Replacement Cost	$3,053,066
Financial	Operator cost (scheduled and reactive maintenance) per connection	$370.78/connection
Demand (m³) (1 Jan – 31 Dec 2020)	Average daily	310
	Peak daily	631
	Minimum daily	8.4
	Average daily per connection	1.47
Type of Supply		High pressure with restricted and unrestricted
Target Pressure & Flow at boundary	Pressure	>310kPa (150kPa restricted)
Target Pressure & Flow at boundary	Flow	>20L/min (±10% maric restricted)
Sustainability	Well Security	Unsecure

20.2 Key Issues

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

Table 20‑1 Sheffield/Waddington Scheme Issues

What's the Problem	What we plan to do
Required infrastructure upgrades include pump upgrades, mains duplication and treatment plant upgrades.	Council confirm its renewal programme and align renewals with required upgrades to ensure efficiencies prior to undertaking the works.

20.3 Overview & History

Sheffield/Waddington townships were the last major townships in the Malvern County Council to be reticulated. Previously household water was obtained by either the use of stock water races, shallow wells or rain water tanks that were subject to contamination.

Sheffield/Waddington water supply provides treated surface water from two shallow wells located in Hawkins River gravels (adjacent to Hawkins River) to properties located in both the Sheffield and Waddington townships. The water is treated by UV disinfection.

The scheme was installed in 1990 as an unrestricted water supply with full “Fire Fighting Capacity" at the time. Extensions to the scheme into the rural area occurred in 1994 and 1996. These extensions were only for domestic use and are restricted to 2m³ per day.

CPW shared water use agreement.

The Council's Long Term Plan 2015-2025 identifies one of the major projects to be the Council's commitment to 'work with Central Plains Water to develop a concept for converting the Kowai River sourced water race network (part of the Malvern Water Race Scheme) into a combined water race and irrigation network. This concept will then be used for further consultation with the community.

The Council entered into agreement with CPW on 16th December 2016. The philosophy of the Agreement is to achieve a mutually beneficial cost neutral position. While the Scheme will benefit from a potential 200l/s of reliable water for irrigation, the added value the Scheme will provide to the community includes providing a robust and secure long term piped water supply to both the Sheffield and Springfield drinking water treatment stations. Which, from a water quality perspective enables the Council to avoid use of shallow groundwater during periods of high turbidity in adjoining rivers, or as required for capacity augmentation; and providing the necessary water quantity to support future township expansion. In addition, a piped stock water supply to shareholders and non-shareholders will ensure this historical network is upgraded to a high quality, efficient utility.

Figure 20-1
SHEFFIELD WADDINGTON Water - Scheme map
Open larger map: 'Water Scheme'

Figure 20‑2 Scheme Schematic

20.4 System Capacity

This water supply was designed as an unrestricted supply but later extensions into the rural area were provided for domestic use and are restricted to 2m³/day.

Table 20‑2 Capacity Summary

	Flow Rate (L/s)	Daily Volume (m³)	Annual Volume (m³)	Comments
Abstraction Capacity	12.5	1080	-	Two bore pumps
Treatment Capacity	>= abstraction	-	-	UV due for renewal
Consented Take	11.7	1010	245,430	CRC173786 **
Peak Demand	15 (typical)	726 *	118,000

* 1 March 2015 ** Consent allows water to be shared as part of a water users group. Refer CRC173786 & CRC173785

20.5 Resource Consents

The Sheffield/Waddington water supply has a number of resource consents. Table 20‑3 shows the water take permitted by the resource consents for this scheme.

Table 20‑3 Resource Consents

Consent

Description

Location

Date Issued

Expiry Date

Consented Max Instantaneous Flow (L/s)

Consented Max Daily Volume (m³/day)

CRC173786

To take and use groundwater

Roecombe Road, SHEFFIELD

7-Feb-17

4-May-36

11.7

1010

20.6 Water Quality

The Sheffield/Waddington supply is a non-secure source which is currently sampled twice weekly at the source, treatment plant and weekly in the reticulation zone.

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

Source

There have been 117 incidences of E. coli identified in source water samples during this period, highlighting the importance of water treatment for this scheme.

Figure 20‑3 E. coli Transgressions - Source

Treatment

There have been two E. coli treatment transgressions during this period; in August 2012 and March 2020.

Zone

There have been five E. coli Zone transgressions during this period.

Figure 20‑4 E. coli transgression – Reticulation Zone

Chemical Analysis

The following is a summary of the raw water chemical analysis carried out at the Sheffield/Waddington Water Supply.

Table 20‑4 Sheffield/Waddington Water Supply Raw Water Chemical Analysis Summary

Parameter	Standards	2015	2017	Status
Total Lead (g/m3)	0.01 (Maximum Acceptable Value)	0.00025	0.001670	✓
pH (pH units)	7-8.5 (Guideline Value)	7.2	7.0	✓
Total Hardness (g/m3 as CaCO₃)	<200 (Guideline Value)	52	45.2	✓
Total Calcium (g/m3)	n/v	13.1	11.70	✓
Total Iron (g/m3)	<0.2 (Guideline Value)	<0.021	< 0.021	✓
Total Sodium (g/m3)	<200 (Guideline Value)	8.7	7.89	✓
Nitrate - Nitrogen (g/m3)	11.3 (Maximum Acceptable Value)	3	2.9	✓

20.7 Scheme Assets

A summary of material and diameter for pipes in Sheffield/Waddington is shown below in Figure 20‑5 and Figure 20‑6.

Figure 20‑5 Pipe Material – Sheffield/Waddington

Figure 20‑6 Pipe Diameter – Sheffield/Waddington

20.8 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.

20.9 Photos of Main Assets

Photo 1: Well No. 2 (typical of both wells) with Reservoir on hill in background (Well No. 1 further along road)

Photo 2: Treatment Shed

20.10 Risk Assessment

A risk assessment has been undertaken for the Sheffield/Waddington 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 20‑5 outlines the risk priority rating, Table 20‑6 outlines the risks and the list of key projects is found in Table 20‑11.

Table 20‑5 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 20‑6 Risks – Sheffield/Waddington

Risk	Action/Project	Year Identified	2014 Risk Rating	2017 Risk Rating	Residual Risk Rating
Inability to flush wells	Install flushing points on wells	2014	27	7	7
Inadequate treatment	Design new treatment system UV and Filtration	2014	40	7	7
Inadequate treatment	Install filtration	2014	40	40	40
Electrical failure due to lightning or network spikes	Install surge diverters	2014	10	10	10
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	27	2.1
Non-consented activities	Renewal of consents	2014	27	27	6
Bore head risks	raise above ground and backflow	2017		10	1
inadequate chlorine residence time	direct pipe to res	2017		27	0.7

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

20.11 Asset Valuation Details

The total replacement value of assets within the Sheffield/Waddington water scheme is $4,384,297 with further details in Table 20‑7 below.

Table 20‑7 Replacement Value, Sheffield/Waddington

Asset Class 1	Asset Class 2	Sum of Replacement Value
Plant and Equipment		$688,459
Water Reticulation	Hydrant	$34,083
	Lateral	$98,404
	Pipe	$3,335,432
	Supply Point	$187,692
	Valve	$40,227

20.12 Renewals

The renewal profile has been taken from the 2019 5 Waters Valuation. A graph showing the renewals for this scheme are shown by Figure 20‑7 below. There is a backlog of renewals that are overdue. Future renewals are relatively evenly spread across years.

Figure 20‑7 Sheffield/Waddington Water Renewal Profile

20.13 Critical Assets

The criticality model for Sheffield/Waddington 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 20‑8 and Figure 20‑8 below shows the calculated criticality for all of the assets within this scheme that have a recorded known length.

Table 20‑8 Length of Assets per Criticality Level

Criticality Bands		Length (m)
5	Low	33,925
4	Medium-Low	4,057
3	Medium	2,461
2	Medium-High	2,614
1	High	0

Figure 20-8
SHEFFIELD WADDINGTON Water - Criticality map
Open larger map: 'Water Criticality'

20.14 Asset Condition

The asset condition model was run for Sheffield/Waddington 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 20‑9 below shows the level of asset condition for these assets within this scheme that have a recorded known condition.

Figure 20-9
SHEFFIELD WADDINGTON Water - Condition map
Open larger map: 'Water Condition'

Table 20‑9 provides a description of the condition rating used within the condition model.

Table 20‑9 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 20‑10 shows the known historic pipe failures within this scheme.

Figure 20-10
SHEFFIELD WADDINGTON Water - Pipe Faults map
Open larger map: 'Water Pipe Faults'

20.15 Funding Program

The 10 year budgets are shown by Table 20-10. 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 20-10 Budget Summary

Years	Projects	Capital Projects
2021/2022	-	$70,000
2022/2023	-	$50,000
2023/2024	-	$400,000
2024/2025	-	-
2025/2026	-	-
2026/2027	-	-
2027/2028	-	-
2028/2029	-	-
2029/2030	-	$400,000
2031/2032	-	-
Total	-	$920,000

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 20-11 Key Projects

Account Label	GL	Description	Year 1($)	Year 2($)	Year 3($)	Years 4 to 10	Funding Split *
Capital Projects	-	Second pipe to reservoir	-	-	$400,000	-	TBC
Capital Projects	-	Second reservoir or VSD	$40,000	-	-	$400,000	TBC
Capital Projects	-	Post-UV/filter flushing	$30,000	-	-	-	100% LoS
Capital Projects	-	Additional monitoring sites	-	$50,000			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.