Hartleys Road Water Supply

 

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9.1       ​Scheme Summary

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9.2       Key Issues

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

Table 9‑1 Hartleys Road Scheme Issues

9.3       Overview & History

Malvern Hills Rural Water Scheme (MHRWS) was installed from 1974 to 1978 for stock and domestic use for the area from Russell's Flat to the Selwyn River, but was extended to serve the townships of Whitecliffs, Glentunnel and Coalgate. The scheme was designed as a restricted supply with flow rates of about 90L/ha/day including domestic use.  Water is provided at low pressure and flow to the customer's storage tanks.

The MHRWS included two separate supply, treatment and distribution networks which are now known separately as Dalethorpe Water Supply and Hartleys Water Supply. The Hartley​s Road Water Supply is the northern part of the MHRWS and covers approximately 13,695ha of rural land. The intake (known as the Hartleys Road pump station) is located 2km north of Whitecliffs adjacent to the Selwyn River. 

The water treatment plant was upgraded with 1 micron (0.001mm) filtration (installed mid 2017) followed by a new UV treatment system (installed 2015-16). This upgrade has been successful with no transgressions (contamination) at the treatment plant being detected. The subsequent stage to this upgrade was the addition of permanent chlorination. Chlorination was a critical part of the upgrade and provides a residual disinfectant in the distri​bution system, to minimise the impact of any regrowth or contamination that could potentially enter the distribution system post treatment. Chlorination of this supply commenced 4 October 2018.​

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​​ Figure 9-1
HARTLEYS Water - Scheme map
Open larger map: 'Water Scheme'

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Figure 9‑2 Scheme Schematic

9.4       System Cap​​acity

The Hartleys Road Water Supply provides water to a large rural area.  This is used for stock and other on-farm purposes, as well as for residential drinking water.  The towns of Whitecliffs, Glentunnel and Coalgate also receive water from the scheme. Water is supplied to a tank at each point of supply via a flow restrictor that limits the daily volume to an agreed allocation (2000L/day per dwelling plus 65 L/day/ha).  Peak day demand is well within current abstraction capacity. Further investigation and analysis would be required to confirm the adequacy of distribution capacity if the scheme area were to be expanded.​

Table 9‑2 Capacity Summary​

 * 2017

** Jan 2020

*** 2019/20

9.5       Resource Consents

The Hartleys Road Water Supply has one resource consent. Table 9‑3 shows the water take permitted by the resource consent for this scheme.

Table 9‑3 Resource Consents

9.6       Water Quality

The Hartleys Road​ rural water supply consists of two separate supplies; Dalethorpe and Hartleys Road. Both of these sources are non-secure. At Dalethorpe the source, treatment plant and reticulation zone are sampled twice weekly. At Hartleys Road the source, treatment plant and reticulation is sampled weekly.

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

Source

There have been 95 incidences of E. coli identified in source water during this period for Hartleys Road, highlighting the importance of water treatment for this scheme.

​Figure 9‑3 E. coli Transgressions – Source Hartleys Road

Treatment

There was one E. coli treatment transgression during this period for Hartleys Road in August 2015.

Zone

There have been two transgressions during this period for Hartleys Road, one in November 2013 and one in Jan 2017.

​Chemical Analysis

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

Table 9‑4 Malvern Hills Rural Water Supply Raw Water Chemical Summary

9.7       Scheme Assets

A summary of material and diameter for pipes in Hartleys Road Water Supply is shown by Figure 9‑4 and Figure 9‑5.

Figure 9‑4 Pipe Material – Malvern Hills

​Figure 9‑5 Pipe Diameter – Malvern Hills

9.8       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.

9.9       Photos of Main Assets

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​​ Photo 1: View of Hartleys Rd shallow well intake	​ Photo 2: Hartleys Rd treatment plant and booster PS
​ Photo 3: View of Hartleys Rd high-level storage reservoirs

9.10       Risk Assessment

A risk assessment has been undertaken for the Hartleys Road Water Supply. 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 9‑5 outlines the risk priority rating, Table 9‑6 outlines the risks and the list of key projects is found in Table 9‑11. 

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

Table 9‑5 Risk Priority Rating

Table 9‑6 Risks – Hartleys Road

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9.11       Asset Valuation Details​

The total replacement value of assets within the Hartleys Road​ water scheme is $10,867,661 with further details in Table 9‑7 below.

Table 9‑7 Replacement Value, Hartleys Road

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9.12       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 9‑6 below. ​

​Figure 9‑6 Hartleys Road Water Renewal Profile​

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9.13       Critical Assets

The criticality model for Malvern Hills 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 9‑8 and Figure 9‑7 below shows the calculated criticality for all of the assets within this scheme that have a recorded known length.

Table 9‑8 Length of Assets per Criticality Level

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​​ Figure 9-7
HARTLEYS Water - Criticality
Open larger map: 'Water Criticality'

9.14       Asset Condition

The asset condition model was run for Hartleys Road 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 9‑8 below shows the level of asset condition for these assets within this scheme that have a recorded known condition. Table 9‑9 provides a description of the condition rating used within the condition model.

The number of pipe faults is also measured through the asset management system. Figure 9‑9​ shows the known historic pipe failures within this scheme.

Table 9‑9 Asset Condition Grading

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​​ Figure 9-8
HARTLEYS Water - Condition
Open larger map: 'Water Condition'

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​​ Figure 9-9
HARTLEYS Water - Pipe Faults map
Open larger map: 'Water Pipe Faults'

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​9.15       Funding Program

The 10 year budgets are shown by Table 9-10. Bu​dgets 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 9-10 Budget Summary

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 9-11​ Key Projects​

 * 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.​​​​​​