<<
9.1 Scheme Summary
Estimated Population Served
| 1,493
|
Scheme Coverage (1 Jan 2021)
| Full Charges
|
120
|
Half Charges | 0
|
>1 Charges
|
3
|
System Components
| Bores/Intakes (No.)
| 1 Intake
|
Treatment/Disinfection | 1 Filtration + UV at Hartleys Road
|
Reservoirs (No.) | 6 Hartleys Rd – 2 concrete reservoirs, Cairn Hill – 1 plastic tank, Whitecliffs – 1 plastic tank, Glentunnel – 1 plastic tank, Waireka – 1 Plastic tank |
Pump Stations (No.)
| 1
|
Piped (m) |
142,748 |
History | Original scheme installation date | 1974-78
|
Value ($)
| Replacement Cost | $10,867,661
|
Depreciated Replacement Cost
| $6,593,410
|
Financial
| Operator cost (scheduled and reactive maintenance) per connection
| $351.39/connection
|
Demand (m3)
(1 Jan – 30 Dec 2020)
| Average daily
|
1,029
|
Peak daily
|
1,344
|
Minimum daily | 53.1
|
Average daily per connection
| 1.72
|
Type of Supply | | Restricted
|
Target Pressure & Flow at boundary
| Pressure | >150kPa
|
Flow | ±10% maric size
|
Sustainability | Well Security | Unsecure |
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
Achieving compliance with the Health Act and amendments will require additional treatment at the intake, including chlorination. | Council will confirm the requirements for the Rural Agricultural Water Supplies from 2016. This will include consideration of the Whitecliffs/Glentunnel/Coalgate township split and headworks supply options. |
Over allocation in selected areas has had a significant effect on levels of service. Modelling has confirmed under supply in some sections of the reticulation. Future renewals and replacements must be carried out in a manner that ensures levels of service are not affected. | Council will implement capital works plan to provide water treatment upgrades to meet the DWSNZ, |
The condition assessment and renewal programme for pipe main replacement to ensure sufficient funding is available when replacement is required.
|
Ongoing inspections and sampling of pipes at time of repair. |
Council require easements/agreements to ensure access to reticulation mains. | Council will identify critical assets requiring easements/agreements and acquire these at time of upgrade works.
|
Catchment management
| To encompass a holistic view of the drinking water supply improved liaison with ECan and study of water quality within the water supply protection zones are being investigated.
|
Pressure zoning
| Pressure zoning will be considered including additional pressure monitoring in the reticulation network. This is proposed to be part of the developing the Target Pressure Plan and Network Management Strategy.
|
Over-allocation of water units
| Council are assessing the allocation of water units throughout the scheme to ensure that the allocation of water to consumers does exceed water supply capacity/consented water allocation.
|
Backflow – there are a small number of medium risk commercial connections as well as domestic connections, with only air gaps, that the scheme is potentially vulnerable to for potential backflow issues.
| There is currently a district wide backflow prevention project underway.
|
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 Hartleys 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 distribution 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.
Figure 9‑2 Scheme Schematic
9.4 System Capacity
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
Abstraction Capacity | 14.0
| 1,633
| -
| 2 x pumps (duty/standby) |
Consented Take
| 18.9
| 1,625
| 390,000 | CRC010904
|
Filter Capacity
| 27.99
| | |
|
UV Capacity
| 58.5
| | | Max flow at 90% UVT
|
Peak Demand
| Unknown
| 1,404 * 1,344 **
| 385,819 ***
|
|
* 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
CRC010904
| To take and use water.
| Hartleys Road, WHITECLIFFS | 25-Nov-09 | 19-Nov-44 | 18.9 | 1,625
|
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
Total Lead (g/m3) | 0.01 (Maximum Acceptable Value)
| <0.0001
| 0.00073
| 0.00043
| 0.00016
| <0.00011 | <0.00011
| 0.000126
| <0.00011
| ✓
|
pH (pH units) | 7-8.5 (Guideline Value)
| 7
| 7.2
| 7
| 7.4
| 7.1
| 7.2
| 7.4
| 7.3
| ✓
|
Total Hardness (g/m3 as CaCO3) | <200 (Guideline Value)
| 39
| 36
| 37
| 39
| 43
| 40.2
| 43.8
| 34.3
| ✓
|
Total Calcium (g/m3) | n/v | 11
| 10.6
| 10.8
| 11.3
| 12.8
| 11.91
| 13.44
| 9.97
| ✓
|
Total Iron (g/m3) | <0.2 (Guideline Value)
| <0.02
| 0.053
| <0.021
| <0.021 | <0.021 | <0.021
| <0.021
| <0.021
| ✓ |
Total Sodium (g/m3) | <200 (Guideline Value)
| 4.5
| 4.6
| 4.7
| 4.8
| 5.15 | 5.26
| 5.32
| 4.46
| ✓
|
Nitrate - Nitrogen (g/m3) | 11.3 (Maximum Acceptable Value)
| 0.92
| 0.28
| 0.20
| 0.25 | 0.468 | 0.765
| 0.613
| 0.444
| ✓
|
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
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
> 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 9‑6 Risks – Hartleys Road
Contamination within reticulation | Investigate Chlorination | 2014 | 12 | 12 | 12
|
Lack of SCADA results in undetected failures | Install additional SCADA sites - Cairn Hill | 2014 | 20 | 3.5 | 3.5 |
Land Owner Access |
| 2014 | 9 | 9 | 12 |
Contamination |
Backflow preventer needed well head to be brought above ground |
2014 |
12 |
12 |
12 |
Electrical failure due to lightning or network spikes |
Install surge diverters |
2014 |
6 |
2.1 |
2.1 |
Failure to meet NES water meter standards |
NES Water Meter Compliance |
2014 |
20 |
6 |
6 |
Non-consented activities |
Renewal of consents |
2014 |
27 |
27 |
6 |
Inadequate treatment under all conditions |
Install filtration |
2017 | |
20 |
3.5 |
Scheme impacted by poor water quality |
auto flush |
2017 |
|
45 |
20 |
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
Plant and Equipment
| $703,734 |
Water Reticulation
| Fire
| $42,476
|
|
Hydrant | $14,278 |
Lateral | $344,377
|
Pipe | $9,225,411
|
Supply Point | $447,643
|
Valve | $89,742
|
9.12 Renewals
The renewal profile has been taken from the 2019 5 Waters Valuation. A graph showing the renewals for this scheme are shown by Figure 9‑6 below.
Figure 9‑6 Hartleys Road Water Renewal Profile
9.13 Critical Assets
The criticality model for Malvern Hills has been updated for the 2021 AcMP. The methodology of the criticality model can be found in 5Waters Activity Management Plan: Volume 1 and it provides details of how the criticality has been calculated for the reticulation assets. Table 9‑8 and Figure 9‑7 below shows the calculated criticality for all of the assets within this scheme that have a recorded known length.
Table 9‑8 Length of Assets per Criticality Level
5
| Low
| 106,661
|
4
| Medium-Low | 24,155
|
3
| Medium | 3,754
|
2
| Medium-High | 6,362
|
1
| High | 0 |
9.14 Asset Condition
The asset condition model was run for Hartleys Road in 2021. The methodology of the model can be found in 5Waters Activity Management Plan: Volume 1 which provides details of how the model has been calculated for the pipe reticulation assets. Figure 9‑8 below shows the level of asset condition for these assets within this scheme that have a recorded known condition. Table 9‑9 provides a description of the condition rating used within the condition model.
The number of pipe faults is also measured through the asset management system. Figure 9‑9 shows the known historic pipe failures within this scheme.
Table 9‑9 Asset Condition Grading
1.0 | Excellent |
2.0 | Good |
3.0 | Moderate |
4.0 | Poor |
5.0+ | Fail |
9.15 Funding Program
The 10 year budgets are shown by Table 9-10. Budgets are split into expenditure, renewals, projects and capital projects. Expenditure and renewals have been reported on a district-wide basis in Volume 1.
All figures are ($) not adjusted for CPI “inflation". They are calculated on historical data, and population growth where relevant.
Table 9-10 Budget Summary
2021/2022 | $5,000
| $202,000
|
2022/2023
| $10,000
| $175,000
|
2023/2024 | -
| $20,000
|
2024/2025 | -
| -
|
2025/2026 | -
| -
|
2026/2027 | -
| -
|
2027/2028 | -
| - |
2028/2029
| -
| -
|
2029/2030
| -
| -
|
2031/2032
| -
| -
|
Total | $15,000
| $397,000
|
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 9-11 Key Projects
Capital Projects
| -
| Additional 7 monitoring sites
| -
| $175,000
| -
| -
| 100% LoS
|
Capital Projects
| -
| Auto-flushing at Hartleys Road WTP
| $200,000
| -
| -
| -
| 100% LoS
|
Capital Projects
| -
| Stock fence around Cairn Hill reservoir
| -
| -
| $20,000
| -
| 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.
<<
5-Waters Volume 2 - Water Supplies