Additional Reading for Session 5B: Case Study of Water Corporation’s Water Forever Plan Context Rainfall in Western Australia has declined by 12 per cent since 1990 and run-off into Perth’s main supply dams has dropped by more than half. Water Forever: Towards Climate Resilience, released in 2009, was developed with the community and industry and is the Water Corporation’s 50 year plan to deliver sustainable water and wastewater services. The plan is driven by the need to ensure Water Forever:
in an even drier climate; with twice as many people and less environmental impact The Corporation is striving to achieve our Vision of - Water Forever, Zero Footprint and Great Place. This is a fine balancing act between providing water for the long term, and reducing the environmental impact of our operations while supporting our state and communities to grow and prosper.
The Corporation’s goal to avoid total external sprinkler bans as a water resource management option has resulted in it adopting a multi-faceted approach which includes improving water efficiency, introducing water recycling and developing new climate independent sources to ensure water forever. This case study shows how the Water Forever plan directly impacts on water resource asset management. Clear Alignment of AM Planning & Corporation objectives The Corporation’s Vision, which includes the Water Forever plan as a crucial component, cascades into the Corporation’s overall business planning framework. The intent is clearly articulated in all planning documents from the Statement of Corporate Intent through to the Strategic Asset Management Plan and supporting asset management planning documents. These documents are used to inform the capital investment and operating budgetary processes from a growth, maintenance and renewals perspective. The recently introduced Strategic Investment Business Case concept is a further improvement to the Corporation’s capital investment prioritisation process ensuring that the Executive can direct available capital funds to the most strategically important business outcomes – one of which is reliable water supply. The alignment is both robust and flexible enough to integrate externally or internally driven changes to levels of service (including growth) and business objectives. How the key
corporate planning documents, and the supporting technical work, link together is shown in Figure 1 below.
Strategic Development Plan & Statement of Corporate Intent
Strategic Asset Management Plan & Infrastructure Assets Policy
Strategic Investment Business Cases (Growth, Renewals, Water Loss)
Asset Class Strategies
Planning Studies & Modelling (informing growth/water loss)
Renewals Strategies (incl. asset condition strategies)
Maintenance Strategies and Standards
Figure 1 Connectivity between Corporate objectives and Asset Management Planning Information Management A key requirement to enable robust water source planning, to meet Water Corporation’s objectives under Water Forever, is having the right data and systems to support effective asset management decision making. From a water source planning perspective this requires reliable data on:
available natural water sources – rainfall, run-off and groundwater levels; information on trends in per capita use – both residential and non-residential; information on system water losses; and growth forecasts information on changing standards (reliability, quality etc)
Significant effort has gone into collecting/collating and analysing data to meet these needs. The data shown below in Figure 2 highlights the significant reduction in stream flows into the Water Corporation’s major surface water sources over the last 30 years – a trend that has worsened in recent years. This, data with the indication of climate change, has resulted in the Water Corporation recognising the need for greater water efficiency and less reliance on climate dependent sources.
Figure 2 Total annual stream flows An ongoing task now is to monitor per capita consumption and total consumption trends to ensure the Water Forever targets are being achieved. Similarly, water losses need to be monitored and Water Corporation uses the Infrastructure Leakage Index (ILI) for each of its major systems to do this. Water Forever incorporates efficiency/demand reduction targets going forward and failure to achieve these would require an increased need for new water sources. Figure 3 below shows trends/forecasts for population growth, per capita consumption and total consumption. This shows a trending decrease in per capita consumption, reflecting the success of the extensive water efficiency programs for both residential customers and major non-residential customers. It also shows increasing population over time but a lower trending increase in total consumption. The long term water resource planning revolves around addressing the supply/demand gap that occurs as population growth outstrips the gains achieved from water efficiency and water loss reduction programs.
Figure 3 Perth Water Statistics Risk Management and Appropriate Innovation in Asset Management To deliver Water Forever, the Water Corporation manages its network effectively in order to provide a sustainable service within a dynamic regulatory paradigm. The ability of our systems to provide accurate water balances for demand and supply is a crucial pre-requisite for facilitating Water Forever. In the context of managing the capability of our schemes and networks, extensive effort has been put into the development of system modelling and planning tools to improve our long term asset investment planning. ď‚§
Planning for growth and demand
The Corporation has developed a System Capability Forecasting Tool which draws data from corporate systems, models the data against agreed risk criteria and generates information for capacity/upgrade decisions to address changing demands. Data requirements for this tool include system pressures/flows, data on per capita/per property consumption and data on the number of connected properties/forecast new property connections. Links are being created between this tool and other Corporate data sources such as PI (data archive for data collected via SCADA), GRANGE (the customer data) and DeveloperNet (for new property forecasts) so that data input can be automated wherever possible. ď‚§
Water Loss management
The Corporation has an overarching Water Loss Management strategy in place which includes the following : -
an annual active leak detection program in both our metropolitan and country areas using latest technology which aligns to leaks and bursts patterns. pressure management program being implemented, which will address the excessive pressure in the distribution and reticulation network and lead to potential water 4
savings through reduced customer consumption and reduced water loss due to leakage and burst mains. Condition assessment technology â€“ currently the Water Corporation is trialling the application of Broadband Electromagnetic (BEM) technology in the Perth CBD. BEM methodology is able to identify and locate cast iron wall thinning due to graphitisation and can measure wall thickness as a non-destructive inspection tool. The technique is being used to provide estimates of remaining life. Figure 4 below shows a cross-section of pipe which was removed to enable validation of the results being assessed using BEM technology. Use of this technology will improve the ability to condition assess critical buried assets and ensure more robust renewals planning especially in densely populated areas.
External corrosion (pitting) Variance in wall thickness during manufacturing (8.5mm) Inclusions in irongraphite-matrix during manufacturing
Pipe Invert: agglomeration of cement liner due to insitu lining
Variance in wall thickness during manufacturing (12.5mm) Figure 1: Sample from failed pipe section on 09/04/2013
Figure 4 Sample from failed pipe section in Perth CBD, 2013
A range of metropolitan and regional water efficiency initiatives detailed below, help us work with the community to reduce water use. -
The Corporation recognises the value that smart metering technology adds to its ability to manage its water demand and use and to date has trialled smart meter technology in parts of the state. The results have been positive and in one trial water supplied fell by 837,500kl (10.13%), resulting in an early return on capital expenditure, a reduction in operating costs, overall reduction in non-revenue water and better informed customers. -
Data logging of major customers
Around 10 per cent of the Corporation’s customers are non-residential customers, who use around 26 per cent of the water supplied. This customer group has therefore been an important target for water efficiency programs. A recent trial which focused on data logging proved to be quite successful. Significant leakage was detected and to date 572ML has been saved. The data logging in itself has proven to be a highly successful methodology to enable the Water Corporation to work with customers to find and capture easy to achieve water savings with a relatively high return on investment and low payback period (often less than 12 months). -
Other ongoing programs
As part of an ongoing targeted water efficiency strategy, the Corporation continues with its “customer behaviour change” efforts to reduce water use. To this end, it has embarked on an intensive awareness raising campaign to reduce use, implemented various water efficiency trials in schools and aquatic centres, swapped 130,000 showerheads across the State and introduced a new billing regime to build more “ownership” and awareness with customers. This has built on our previously highly successful and continuing Water Wise Partnership and our now suspended rebates program. In addition over recent years there has been a change of landscape in new development. This is characterised by: - Water wise subdivisions - Smaller block sizes with reduced external water use needs
The Water Corporation has an extensive network of wastewater effluent recycling schemes throughout the state. These largely supply community amenities such as sporting fields and public open space, in-plant requirements in wastewater treatment plants (previously some of our highest potable water demands) and industry. The scheme supplying our capital city (Perth) is a combination of surface water, groundwater and climate independent sources (desalination). Both the surface and groundwater sources have been heavily impacted by reducing rainfall. To supplement our groundwater availability the Corporation has been trialing Ground Water Replenishment, which has now received government endorsement for full scale implementation. The trial was based on an integrated strategy using latest technology developments, extensive regulatory liaison and strategic customer engagement to further secure future supply. Based on the success of the recent trial, the Water Corporation will be investing in a new, expanded deep groundwater replenishment network over the next ten years that will increase our sustainable groundwater abstraction from deeper aquifers, protecting the natural environment and securing future groundwater supplies.
New Water Sources
Declining rainfall has seen a reduction of inflow into our dams from 338GL/year to less than 67GL/year on average. 6
Despite strong community support for better water wise efficiency, investment in climate independent sources (desalination) has been required and is being completed currently. In 2011/12 water supplied into our largest scheme consisted of: -
31 per cent from surface water (this has steadily reduced over recent years – was once 100%) 46 per cent groundwater 23 per cent from desalinated seawater
The proportion of desalinated water will increase to approximately 50 per cent when the second stage of the Southern Seawater Desalination Plant is fully producing. The Perth Seawater Desalination plant outperformed its rated annual production capacity of 45 billion litres by delivering over 49 billion litres into the largest scheme. Desalination is considered a crucial technological advancement which has assisted the Corporation in securing its water supply as part of its Water Forever strategy. With demand management and new climate independent sources we have replaced 250GL of the loss of inflow into our dams. Groundwater Replenishment and further demand management will enable us to manage the situation for the foreseeable future. Planning is continuing to identify further new source opportunities to be implemented when required. To support the growing demands of our regional schemes, extensive upgrades and additions are planned. Conclusion When it comes to providing an ongoing secure water supply to its customer base Water Corporation faces some unique challenges. These include;
A changing climate that has dramatically reduced run-off into its surface storages over the last 30 years A large geographical coverage with many remote and sparsely populated centres Strong overall state-wide growth that can also be quite volatile in some of the more remote areas impacted by mining
To manage these challenges, Water Corporation has determined clear policy objectives for water supply around which its asset management needs have to be implemented. A prime example of this is the policy not to use total external water use bans during the long dry season but rather to have external use rosters. To meet this policy objective the Water Corporation has generated data from numerous areas in order to make appropriate and informed decisions. This has included studies into areas such as;
End use studies so that water efficiency programs can be well designed Impact of roster systems on peak demands and ultimately on water system design standards Ongoing viability of surface storage yields to determine supply/demand gaps Clear customer usage trends across the multitude of water supply schemes throughout the state so that ‘hot spots’ for supply security can be determined 7
The Water Corporation has then invested in both the assessment and implementation of technology where this has been appropriate. From climate independent water sources (desalination, groundwater replenishment) through more efficient use of existing water sources (leakage monitoring, pressure management, smart metering) appropriate technologies have been used to secure the water supply for the future. The Water Forever document pulls all of these elements together. It reviews the risks to water supply, now and over the next 50 years, and articulates the roadmap that the Water Corporation intends to follow to mitigate the risks and ensure secure water supply to its customers.