The standard base asset life used in the renewal programme and asset valuation for facility assets (major components) are shown in the table below:

Transcription

1 7.3.6 Facilities Background Plant is defined as asset components that pump, store or treat water. Key components include: Pumping stations - pumping of water to within the reticulation Treatment plants Treatment of water Reservoirs storage for emergency and normal daily peak usage Renewal of facility assets is any replacement of equipment or components costing more than $500 (nominal) or restoration of facility components or assets where these do not increase the capacity or performance. The standard base asset life used in the renewal programme and asset valuation for facility assets (major components) are shown in the table below: Table 7-10: Facility Plant Asset Life Facility Asset Asset Life (Years) Bores 60 Datran (SCADA) Control panel Mains board Pump 15 Shed 60 VSD & Soft starts 15 Dosing & Control units PRV 40 UV units 25 Facilities Renewal Details of the water facility assets were obtained from the 2017 asset valuation held in AssetFinda. A check of the asset valuation data was undertaken against the water scheme schematics with the following actions: 30 assets had a base asset life of 1 year. The base lives for each of these assets was adjusted to the default value for its class Corrected the Waikari Reservoir replacement value to $61,762 from $10,561,388. As a result of the above actions the forecasted 10 year facility renewals profile is shown in Figure 7-6 including averaged 10 year expenditure. November 2017 Page 111

2 Figure 7-6: District Wide Water Facilities Renewal Profile This expenditure is influenced by a significant number of water facility assets having a replacement year of 2018 and 2019, and thereby $3,121,000 of renewals being forecasted for the immediate two year period. A review of the replacement year for these assets, utilising operational staff knowledge on asset condition and performance, is required. The 10 year average expenditure reduces to approximately $559,000 ( ), $312,000 ( ), and then $233,000 ( ) over the next 30 year period. The facility renewal profiles for the individual water schemes are provided below. The Annual replacement costs are shown on the left axis and the 10 year average replacement cost is shown on the right axis. Page 112 November 2017

3 Figure 7-7: Water Facilities Renewal Profiles On Demand Schemes Amberley Culverden Hanmer Springs November 2017 Page 113

4 Hawarden - Waikari Leithfield Beach Waiau Township Page 114 November 2017

5 Waipara Restricted Schemes Amuri Plains Ashley November 2017 Page 115

6 Balmoral Blythe Cheviot Page 116 November 2017

7 Hurunui #1 Kaiwara Lower Waitohi November 2017 Page 117

8 Parnassus Peaks Upper Waitohi Page 118 November 2017

9 Waiau RWS Accounting for Asset Renewal Renewal Definition Renewals comprise both planned and reactionary responses to failures and asset components that have performance and risk liability. The relative proportions are different to maintenance, as most of this work can be planned as it is less urgent than maintenance. The split based on recent history, would be 40% (reactionary): 60% (planned) respectively. Examples of reactionary responses for renewals would include: Sudden pump failure and replacement Replacement of pipelines after flood, landslide damage or slow movement of soils Intentional or accidental damage Failure of any major treatment device (water/wastewater) Examples of planned renewals would include: Programmed pump or electrical component replacement Replacement of known sub-standard or deteriorating pipelines Renewal or upgrading telemetric links that are not performing to expectations Replacement of valves, meters or other devices Renewal Policy Selection Criteria for Asset Renewal is fundamentally based on a combination of condition assessment, hydraulic modelling results, Optimised Decision Making and Capacity/Criticality assessment. Council is in the process of formalising renewal selection into a standard framework using pipe age, material, criticality and performance data sets in the first instance. Table 7-11 details a longer list of possible selection criteria. Table 7-11: Renewal Selection Fundamentals Priority Renewal Criteria High Staying ahead of Roading programme(2 year programme) Asset failure has occurred and renewal is the most cost effective option Asset failure of a critical system or component is imminent Does not meet Level of Service Does not meet legislative requirement November 2017 Page 119

10 Priority Medium Low Renewal Criteria Fault has, or is liable to become a risk to public health or receiving environment Failure of non-critical asset is imminent and renewal is the most efficient life cycle cost alternative Fault causes repeated problems Road upgrading scheduled for the current financial year Complaints, re-leaks, odours Reticulation maintenance is high Difficult to repair, due to fragile nature of material, or obsolescence Existing assets have a low level of flexibility and efficiency compared with replacement alternative Existing asset materials or types are such that known problems will develop in time Intervention Strategies The objectives of a Water Renewal Strategy are: Replacement of assets are carried out at the most appropriate time Most effective benefit received from asset renewals Validating the Council s Appropriate Asset Management Level for mains renewals Assist in the compliance of Water and Wastewater reticulation Levels of Service Using the criticality ranking, Risk Aversion can be built into the adjustment of the economic life of high critically assets to shorten their lives. The extent of the factor of safety for an asset was dependent on the level of risk that the Council is willing to accept. Figure 7-8: Risk Aversion and Interventions Process Interventions High Criticality Assets Start of Asset Life Low Criticality Assets (Inspections, Condition assessment & Replacement) 1 2 Life of The Asset. 1 Replaced when risk of failure is not acceptable 3 Risk Aversion 2 End of Physical Life (Asset Fails) Interventions In the 2015 LTP Council approved a renewal budget less than what was presented using the age based renewal approach in the AMP. This approach was adopted due to affordability constraints and a lack of evidence that the pipes at the end of their theoretical life were presenting high risk or operational issues. Following this decision, Council has introduced further criteria into their renewals planning process to identify priority interventions based on asset criticality and performance. 7.4 Asset Criticality An asset criticality evaluation was undertaken in 2017 for water supply mains and facilities and entered against individual assets in AssetFinda. These criticality scores have been used in Page 120 November 2017

11 determining pipeline candidates for renewal interventions. The criticality framework takes into the number of connections, availability of on-demand storage, accessibility to asset location, water source redundancy and priority facilities serviced. Assets are assigned a 1-5 criticality score from Very Low to Very High. Figure 7-9 below shows the total pipe replacement value by criticality type. Figure 7-9: Pipeline Total Replacement Value by Criticality Criticality is considered when prioritising renewal of pipes at the end of their theoretical useful life. A criticality breakdown of replacement values for pipes approaching the end of their lives is shown in Figure 7-10 below. Figure 7-10: Pipe Renewal Profile by Criticality November 2017 Page 121